addd

backend/pom.xml

@@ -0,0 +1,66 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.springframework.boot</groupId>
+    <artifactId>spring-boot-starter-parent</artifactId>
+    <version>3.3.2</version>
+    <relativePath/>
+  </parent>
+  <groupId>com.community</groupId>
+  <artifactId>community-activities</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <name>community-activities</name>
+  <description>Community solar-term activity system</description>
+  <properties>
+    <java.version>17</java.version>
+    <maven.compiler.release>17</maven.compiler.release>
+  </properties>
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-validation</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.mybatis.spring.boot</groupId>
+      <artifactId>mybatis-spring-boot-starter</artifactId>
+      <version>3.0.3</version>
+    </dependency>
+    <dependency>
+      <groupId>com.mysql</groupId>
+      <artifactId>mysql-connector-j</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>cn.dev33</groupId>
+      <artifactId>sa-token-spring-boot3-starter</artifactId>
+      <version>1.38.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.security</groupId>
+      <artifactId>spring-security-crypto</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <optional>true</optional>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>

backend/schema.sql

@@ -0,0 +1,48 @@
+create database if not exists community_activity default character set utf8mb4 collate utf8mb4_general_ci;
+use community_activity;
+
+create table if not exists sys_user (
+  id bigint primary key auto_increment,
+  username varchar(64) not null unique,
+  password_hash varchar(255) not null,
+  nickname varchar(64) not null,
+  phone varchar(32),
+  role varchar(32) not null default 'user',
+  created_at datetime not null,
+  updated_at datetime not null
+);
+
+create table if not exists activity (
+  id bigint primary key auto_increment,
+  title varchar(255) not null,
+  term varchar(64) not null,
+  summary varchar(255),
+  content text,
+  location varchar(255) not null,
+  start_time datetime not null,
+  end_time datetime not null,
+  signup_start datetime not null,
+  signup_end datetime not null,
+  quota int not null,
+  status varchar(32) not null,
+  cover_url varchar(255),
+  created_by bigint,
+  created_at datetime not null,
+  updated_at datetime not null,
+  index idx_activity_status (status),
+  index idx_activity_time (start_time)
+);
+
+create table if not exists activity_signup (
+  id bigint primary key auto_increment,
+  activity_id bigint not null,
+  user_id bigint not null,
+  status varchar(32) not null,
+  checkin_status varchar(32) not null,
+  signed_at datetime not null,
+  canceled_at datetime,
+  checkin_at datetime,
+  unique key uk_activity_user (activity_id, user_id),
+  index idx_activity (activity_id),
+  index idx_user (user_id)
+);

backend/src/main/java/com/community/app/CommunityApplication.java

@@ -0,0 +1,13 @@
+package com.community.app;
+
+import org.mybatis.spring.annotation.MapperScan;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+@MapperScan("com.community.app.mapper")
+public class CommunityApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(CommunityApplication.class, args);
+    }
+}

backend/src/main/java/com/community/app/config/GlobalExceptionHandler.java

@@ -0,0 +1,33 @@
+package com.community.app.config;
+
+import com.community.app.dto.ApiResponse;
+import cn.dev33.satoken.exception.NotLoginException;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+    @ExceptionHandler(IllegalStateException.class)
+    public ApiResponse<Void> handleIllegalState(IllegalStateException ex) {
+        return ApiResponse.fail(ex.getMessage());
+    }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ApiResponse<Void> handleValidation(MethodArgumentNotValidException ex) {
+        String message = ex.getBindingResult().getFieldErrors().isEmpty()
+                ? "参数错误"
+                : ex.getBindingResult().getFieldErrors().get(0).getDefaultMessage();
+        return ApiResponse.fail(message);
+    }
+
+    @ExceptionHandler(NotLoginException.class)
+    public ApiResponse<Void> handleNotLogin(NotLoginException ex) {
+        return ApiResponse.fail("未登录或登录已失效");
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ApiResponse<Void> handleOther(Exception ex) {
+        return ApiResponse.fail("服务器异常");
+    }
+}

backend/src/main/java/com/community/app/config/SaTokenConfig.java

@@ -0,0 +1,32 @@
+package com.community.app.config;
+
+import cn.dev33.satoken.stp.StpInterface;
+import com.community.app.entity.User;
+import com.community.app.service.UserService;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.Collections;
+import java.util.List;
+
+@Configuration
+public class SaTokenConfig {
+    @Bean
+    public StpInterface stpInterface(UserService userService) {
+        return new StpInterface() {
+            @Override
+            public List<String> getPermissionList(Object loginId, String loginType) {
+                return Collections.emptyList();
+            }
+
+            @Override
+            public List<String> getRoleList(Object loginId, String loginType) {
+                User user = userService.findById(Long.valueOf(loginId.toString()));
+                if (user == null) {
+                    return Collections.emptyList();
+                }
+                return Collections.singletonList(user.getRole());
+            }
+        };
+    }
+}

backend/src/main/java/com/community/app/config/WebConfig.java

@@ -0,0 +1,35 @@
+package com.community.app.config;
+
+import cn.dev33.satoken.interceptor.SaInterceptor;
+import cn.dev33.satoken.stp.StpUtil;
+import cn.dev33.satoken.context.SaHolder;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class WebConfig implements WebMvcConfigurer {
+    @Override
+    public void addCorsMappings(CorsRegistry registry) {
+        registry.addMapping("/**")
+                .allowedOrigins("*")
+                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
+                .allowedHeaders("*")
+                .allowCredentials(false)
+                .maxAge(3600);
+    }
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(new SaInterceptor(handle -> {
+                    String method = SaHolder.getRequest().getMethod();
+                    if ("OPTIONS".equalsIgnoreCase(method)) {
+                        return;
+                    }
+                    StpUtil.checkLogin();
+                }))
+                .addPathPatterns("/api/**")
+                .excludePathPatterns("/api/auth/**", "/api/public/**");
+    }
+}

backend/src/main/java/com/community/app/controller/ActivityController.java

@@ -0,0 +1,105 @@
+package com.community.app.controller;
+
+import cn.dev33.satoken.annotation.SaCheckRole;
+import cn.dev33.satoken.stp.StpUtil;
+import com.community.app.dto.ActivityRequest;
+import com.community.app.dto.ActivityView;
+import com.community.app.dto.ApiResponse;
+import com.community.app.entity.User;
+import com.community.app.service.ActivityService;
+import com.community.app.service.SignupService;
+import com.community.app.service.UserService;
+import jakarta.validation.Valid;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/activities")
+public class ActivityController {
+    private final ActivityService activityService;
+    private final SignupService signupService;
+    private final UserService userService;
+
+    public ActivityController(ActivityService activityService, SignupService signupService, UserService userService) {
+        this.activityService = activityService;
+        this.signupService = signupService;
+        this.userService = userService;
+    }
+
+    @GetMapping
+    public ApiResponse<List<ActivityView>> list(@RequestParam(required = false) String status,
+                                                @RequestParam(required = false) String keyword) {
+        User user = currentUser();
+        if (user == null || !"admin".equals(user.getRole())) {
+            status = "published";
+        }
+        return ApiResponse.ok(activityService.list(status, keyword));
+    }
+
+    @GetMapping("/{id}")
+    public ApiResponse<ActivityView> detail(@PathVariable Long id) {
+        ActivityView view = activityService.getView(id);
+        if (view == null) {
+            return ApiResponse.fail("活动不存在");
+        }
+        User user = currentUser();
+        if (user == null || !"admin".equals(user.getRole())) {
+            if (!"published".equals(view.getStatus())) {
+                return ApiResponse.fail("活动未发布");
+            }
+        }
+        return ApiResponse.ok(view);
+    }
+
+    @SaCheckRole("admin")
+    @PostMapping
+    public ApiResponse<Void> create(@Valid @RequestBody ActivityRequest request) {
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        activityService.create(request, userId);
+        return ApiResponse.ok("创建成功", null);
+    }
+
+    @SaCheckRole("admin")
+    @PutMapping("/{id}")
+    public ApiResponse<Void> update(@PathVariable Long id, @Valid @RequestBody ActivityRequest request) {
+        activityService.update(id, request);
+        return ApiResponse.ok("更新成功", null);
+    }
+
+    @SaCheckRole("admin")
+    @PostMapping("/{id}/publish")
+    public ApiResponse<Void> publish(@PathVariable Long id) {
+        activityService.publish(id);
+        return ApiResponse.ok("已发布", null);
+    }
+
+    @SaCheckRole("admin")
+    @PostMapping("/{id}/close")
+    public ApiResponse<Void> close(@PathVariable Long id) {
+        activityService.close(id);
+        return ApiResponse.ok("已结束", null);
+    }
+
+    @PostMapping("/{id}/signup")
+    public ApiResponse<Void> signup(@PathVariable Long id) {
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        signupService.signup(id, userId);
+        return ApiResponse.ok("报名成功", null);
+    }
+
+    @PostMapping("/{id}/cancel")
+    public ApiResponse<Void> cancel(@PathVariable Long id) {
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        signupService.cancel(id, userId);
+        return ApiResponse.ok("已取消报名", null);
+    }
+
+    private User currentUser() {
+        if (!StpUtil.isLogin()) {
+            return null;
+        }
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        return userService.findById(userId);
+    }
+}

backend/src/main/java/com/community/app/controller/AdminController.java

@@ -0,0 +1,44 @@
+package com.community.app.controller;
+
+import cn.dev33.satoken.annotation.SaCheckRole;
+import com.community.app.dto.AdminSignupView;
+import com.community.app.dto.ApiResponse;
+import com.community.app.entity.User;
+import com.community.app.service.SignupService;
+import com.community.app.service.UserService;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/admin")
+@SaCheckRole("admin")
+public class AdminController {
+    private final SignupService signupService;
+    private final UserService userService;
+
+    public AdminController(SignupService signupService, UserService userService) {
+        this.signupService = signupService;
+        this.userService = userService;
+    }
+
+    @GetMapping("/activities/{id}/signups")
+    public ApiResponse<List<AdminSignupView>> listSignups(@PathVariable Long id) {
+        return ApiResponse.ok(signupService.listByActivity(id));
+    }
+
+    @PostMapping("/signups/{id}/checkin")
+    public ApiResponse<Void> checkin(@PathVariable Long id) {
+        signupService.checkin(id);
+        return ApiResponse.ok("签到成功", null);
+    }
+
+    @GetMapping("/users")
+    public ApiResponse<List<User>> listUsers() {
+        return ApiResponse.ok(userService.listAll());
+    }
+}

backend/src/main/java/com/community/app/controller/AuthController.java

@@ -0,0 +1,59 @@
+package com.community.app.controller;
+
+import cn.dev33.satoken.stp.StpUtil;
+import com.community.app.dto.ApiResponse;
+import com.community.app.dto.AuthRequest;
+import com.community.app.dto.AuthResponse;
+import com.community.app.dto.RegisterRequest;
+import com.community.app.entity.User;
+import com.community.app.service.UserService;
+import jakarta.validation.Valid;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/auth")
+public class AuthController {
+    private final UserService userService;
+
+    public AuthController(UserService userService) {
+        this.userService = userService;
+    }
+
+    @PostMapping("/login")
+    public ApiResponse<AuthResponse> login(@Valid @RequestBody AuthRequest request) {
+        User user = userService.findByUsername(request.getUsername());
+        if (user == null || !userService.verifyPassword(user, request.getPassword())) {
+            return ApiResponse.fail("用户名或密码错误");
+        }
+        StpUtil.login(user.getId());
+        AuthResponse response = new AuthResponse();
+        response.setToken(StpUtil.getTokenValue());
+        response.setUserId(user.getId());
+        response.setUsername(user.getUsername());
+        response.setNickname(user.getNickname());
+        response.setRole(user.getRole());
+        return ApiResponse.ok("登录成功", response);
+    }
+
+    @PostMapping("/register")
+    public ApiResponse<AuthResponse> register(@Valid @RequestBody RegisterRequest request) {
+        User user = userService.register(request.getUsername(), request.getPassword(), request.getNickname(), request.getPhone());
+        StpUtil.login(user.getId());
+        AuthResponse response = new AuthResponse();
+        response.setToken(StpUtil.getTokenValue());
+        response.setUserId(user.getId());
+        response.setUsername(user.getUsername());
+        response.setNickname(user.getNickname());
+        response.setRole(user.getRole());
+        return ApiResponse.ok("注册成功", response);
+    }
+
+    @PostMapping("/logout")
+    public ApiResponse<Void> logout() {
+        StpUtil.logout();
+        return ApiResponse.ok("已退出", null);
+    }
+}

backend/src/main/java/com/community/app/controller/PublicController.java

@@ -0,0 +1,36 @@
+package com.community.app.controller;
+
+import com.community.app.dto.ActivityView;
+import com.community.app.dto.ApiResponse;
+import com.community.app.service.ActivityService;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/public")
+public class PublicController {
+    private final ActivityService activityService;
+
+    public PublicController(ActivityService activityService) {
+        this.activityService = activityService;
+    }
+
+    @GetMapping("/activities")
+    public ApiResponse<List<ActivityView>> list(@RequestParam(required = false) String keyword) {
+        return ApiResponse.ok(activityService.list("published", keyword));
+    }
+
+    @GetMapping("/activities/{id}")
+    public ApiResponse<ActivityView> detail(@PathVariable Long id) {
+        ActivityView view = activityService.getView(id);
+        if (view == null || !"published".equals(view.getStatus())) {
+            return ApiResponse.fail("活动不存在或未发布");
+        }
+        return ApiResponse.ok(view);
+    }
+}

backend/src/main/java/com/community/app/controller/UserController.java

@@ -0,0 +1,37 @@
+package com.community.app.controller;
+
+import cn.dev33.satoken.stp.StpUtil;
+import com.community.app.dto.ApiResponse;
+import com.community.app.dto.SignupView;
+import com.community.app.entity.User;
+import com.community.app.service.SignupService;
+import com.community.app.service.UserService;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/me")
+public class UserController {
+    private final UserService userService;
+    private final SignupService signupService;
+
+    public UserController(UserService userService, SignupService signupService) {
+        this.userService = userService;
+        this.signupService = signupService;
+    }
+
+    @GetMapping
+    public ApiResponse<User> me() {
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        return ApiResponse.ok(userService.findById(userId));
+    }
+
+    @GetMapping("/signups")
+    public ApiResponse<List<SignupView>> mySignups() {
+        Long userId = Long.valueOf(StpUtil.getLoginId().toString());
+        return ApiResponse.ok(signupService.listByUser(userId));
+    }
+}

backend/src/main/java/com/community/app/dto/ActivityRequest.java

@@ -0,0 +1,124 @@
+package com.community.app.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import java.time.LocalDateTime;
+
+public class ActivityRequest {
+    @NotBlank
+    private String title;
+    @NotBlank
+    private String term;
+    private String summary;
+    private String content;
+    @NotBlank
+    private String location;
+    @NotNull
+    private LocalDateTime startTime;
+    @NotNull
+    private LocalDateTime endTime;
+    @NotNull
+    private LocalDateTime signupStart;
+    @NotNull
+    private LocalDateTime signupEnd;
+    @NotNull
+    private Integer quota;
+    private String status;
+    private String coverUrl;
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getTerm() {
+        return term;
+    }
+
+    public void setTerm(String term) {
+        this.term = term;
+    }
+
+    public String getSummary() {
+        return summary;
+    }
+
+    public void setSummary(String summary) {
+        this.summary = summary;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public String getLocation() {
+        return location;
+    }
+
+    public void setLocation(String location) {
+        this.location = location;
+    }
+
+    public LocalDateTime getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(LocalDateTime startTime) {
+        this.startTime = startTime;
+    }
+
+    public LocalDateTime getEndTime() {
+        return endTime;
+    }
+
+    public void setEndTime(LocalDateTime endTime) {
+        this.endTime = endTime;
+    }
+
+    public LocalDateTime getSignupStart() {
+        return signupStart;
+    }
+
+    public void setSignupStart(LocalDateTime signupStart) {
+        this.signupStart = signupStart;
+    }
+
+    public LocalDateTime getSignupEnd() {
+        return signupEnd;
+    }
+
+    public void setSignupEnd(LocalDateTime signupEnd) {
+        this.signupEnd = signupEnd;
+    }
+
+    public Integer getQuota() {
+        return quota;
+    }
+
+    public void setQuota(Integer quota) {
+        this.quota = quota;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCoverUrl() {
+        return coverUrl;
+    }
+
+    public void setCoverUrl(String coverUrl) {
+        this.coverUrl = coverUrl;
+    }
+}

backend/src/main/java/com/community/app/dto/ActivityView.java

@@ -0,0 +1,132 @@
+package com.community.app.dto;
+
+import java.time.LocalDateTime;
+
+public class ActivityView {
+    private Long id;
+    private String title;
+    private String term;
+    private String summary;
+    private String content;
+    private String location;
+    private LocalDateTime startTime;
+    private LocalDateTime endTime;
+    private LocalDateTime signupStart;
+    private LocalDateTime signupEnd;
+    private Integer quota;
+    private String status;
+    private String coverUrl;
+    private Long signupCount;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getTerm() {
+        return term;
+    }
+
+    public void setTerm(String term) {
+        this.term = term;
+    }
+
+    public String getSummary() {
+        return summary;
+    }
+
+    public void setSummary(String summary) {
+        this.summary = summary;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public String getLocation() {
+        return location;
+    }
+
+    public void setLocation(String location) {
+        this.location = location;
+    }
+
+    public LocalDateTime getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(LocalDateTime startTime) {
+        this.startTime = startTime;
+    }
+
+    public LocalDateTime getEndTime() {
+        return endTime;
+    }
+
+    public void setEndTime(LocalDateTime endTime) {
+        this.endTime = endTime;
+    }
+
+    public LocalDateTime getSignupStart() {
+        return signupStart;
+    }
+
+    public void setSignupStart(LocalDateTime signupStart) {
+        this.signupStart = signupStart;
+    }
+
+    public LocalDateTime getSignupEnd() {
+        return signupEnd;
+    }
+
+    public void setSignupEnd(LocalDateTime signupEnd) {
+        this.signupEnd = signupEnd;
+    }
+
+    public Integer getQuota() {
+        return quota;
+    }
+
+    public void setQuota(Integer quota) {
+        this.quota = quota;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCoverUrl() {
+        return coverUrl;
+    }
+
+    public void setCoverUrl(String coverUrl) {
+        this.coverUrl = coverUrl;
+    }
+
+    public Long getSignupCount() {
+        return signupCount;
+    }
+
+    public void setSignupCount(Long signupCount) {
+        this.signupCount = signupCount;
+    }
+}

backend/src/main/java/com/community/app/dto/AdminSignupView.java

@@ -0,0 +1,105 @@
+package com.community.app.dto;
+
+import java.time.LocalDateTime;
+
+public class AdminSignupView {
+    private Long id;
+    private Long activityId;
+    private Long userId;
+    private String username;
+    private String nickname;
+    private String phone;
+    private String status;
+    private String checkinStatus;
+    private LocalDateTime signedAt;
+    private LocalDateTime canceledAt;
+    private LocalDateTime checkinAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getActivityId() {
+        return activityId;
+    }
+
+    public void setActivityId(Long activityId) {
+        this.activityId = activityId;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getNickname() {
+        return nickname;
+    }
+
+    public void setNickname(String nickname) {
+        this.nickname = nickname;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCheckinStatus() {
+        return checkinStatus;
+    }
+
+    public void setCheckinStatus(String checkinStatus) {
+        this.checkinStatus = checkinStatus;
+    }
+
+    public LocalDateTime getSignedAt() {
+        return signedAt;
+    }
+
+    public void setSignedAt(LocalDateTime signedAt) {
+        this.signedAt = signedAt;
+    }
+
+    public LocalDateTime getCanceledAt() {
+        return canceledAt;
+    }
+
+    public void setCanceledAt(LocalDateTime canceledAt) {
+        this.canceledAt = canceledAt;
+    }
+
+    public LocalDateTime getCheckinAt() {
+        return checkinAt;
+    }
+
+    public void setCheckinAt(LocalDateTime checkinAt) {
+        this.checkinAt = checkinAt;
+    }
+}

backend/src/main/java/com/community/app/dto/ApiResponse.java

@@ -0,0 +1,52 @@
+package com.community.app.dto;
+
+public class ApiResponse<T> {
+    private boolean success;
+    private String message;
+    private T data;
+
+    public ApiResponse() {
+    }
+
+    public ApiResponse(boolean success, String message, T data) {
+        this.success = success;
+        this.message = message;
+        this.data = data;
+    }
+
+    public static <T> ApiResponse<T> ok(T data) {
+        return new ApiResponse<>(true, "success", data);
+    }
+
+    public static <T> ApiResponse<T> ok(String message, T data) {
+        return new ApiResponse<>(true, message, data);
+    }
+
+    public static <T> ApiResponse<T> fail(String message) {
+        return new ApiResponse<>(false, message, null);
+    }
+
+    public boolean isSuccess() {
+        return success;
+    }
+
+    public void setSuccess(boolean success) {
+        this.success = success;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    public T getData() {
+        return data;
+    }
+
+    public void setData(T data) {
+        this.data = data;
+    }
+}

backend/src/main/java/com/community/app/dto/AuthRequest.java

@@ -0,0 +1,26 @@
+package com.community.app.dto;
+
+import jakarta.validation.constraints.NotBlank;
+
+public class AuthRequest {
+    @NotBlank
+    private String username;
+    @NotBlank
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+}

backend/src/main/java/com/community/app/dto/AuthResponse.java

@@ -0,0 +1,49 @@
+package com.community.app.dto;
+
+public class AuthResponse {
+    private String token;
+    private Long userId;
+    private String username;
+    private String nickname;
+    private String role;
+
+    public String getToken() {
+        return token;
+    }
+
+    public void setToken(String token) {
+        this.token = token;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getNickname() {
+        return nickname;
+    }
+
+    public void setNickname(String nickname) {
+        this.nickname = nickname;
+    }
+
+    public String getRole() {
+        return role;
+    }
+
+    public void setRole(String role) {
+        this.role = role;
+    }
+}

backend/src/main/java/com/community/app/dto/PageResponse.java

@@ -0,0 +1,32 @@
+package com.community.app.dto;
+
+import java.util.List;
+
+public class PageResponse<T> {
+    private long total;
+    private List<T> list;
+
+    public PageResponse() {
+    }
+
+    public PageResponse(long total, List<T> list) {
+        this.total = total;
+        this.list = list;
+    }
+
+    public long getTotal() {
+        return total;
+    }
+
+    public void setTotal(long total) {
+        this.total = total;
+    }
+
+    public List<T> getList() {
+        return list;
+    }
+
+    public void setList(List<T> list) {
+        this.list = list;
+    }
+}

backend/src/main/java/com/community/app/dto/RegisterRequest.java

@@ -0,0 +1,45 @@
+package com.community.app.dto;
+
+import jakarta.validation.constraints.NotBlank;
+
+public class RegisterRequest {
+    @NotBlank
+    private String username;
+    @NotBlank
+    private String password;
+    @NotBlank
+    private String nickname;
+    private String phone;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public String getNickname() {
+        return nickname;
+    }
+
+    public void setNickname(String nickname) {
+        this.nickname = nickname;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+}

backend/src/main/java/com/community/app/dto/SignupView.java

@@ -0,0 +1,114 @@
+package com.community.app.dto;
+
+import java.time.LocalDateTime;
+
+public class SignupView {
+    private Long id;
+    private Long activityId;
+    private String activityTitle;
+    private String term;
+    private String location;
+    private LocalDateTime startTime;
+    private LocalDateTime endTime;
+    private String status;
+    private String checkinStatus;
+    private LocalDateTime signedAt;
+    private LocalDateTime canceledAt;
+    private LocalDateTime checkinAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getActivityId() {
+        return activityId;
+    }
+
+    public void setActivityId(Long activityId) {
+        this.activityId = activityId;
+    }
+
+    public String getActivityTitle() {
+        return activityTitle;
+    }
+
+    public void setActivityTitle(String activityTitle) {
+        this.activityTitle = activityTitle;
+    }
+
+    public String getTerm() {
+        return term;
+    }
+
+    public void setTerm(String term) {
+        this.term = term;
+    }
+
+    public String getLocation() {
+        return location;
+    }
+
+    public void setLocation(String location) {
+        this.location = location;
+    }
+
+    public LocalDateTime getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(LocalDateTime startTime) {
+        this.startTime = startTime;
+    }
+
+    public LocalDateTime getEndTime() {
+        return endTime;
+    }
+
+    public void setEndTime(LocalDateTime endTime) {
+        this.endTime = endTime;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCheckinStatus() {
+        return checkinStatus;
+    }
+
+    public void setCheckinStatus(String checkinStatus) {
+        this.checkinStatus = checkinStatus;
+    }
+
+    public LocalDateTime getSignedAt() {
+        return signedAt;
+    }
+
+    public void setSignedAt(LocalDateTime signedAt) {
+        this.signedAt = signedAt;
+    }
+
+    public LocalDateTime getCanceledAt() {
+        return canceledAt;
+    }
+
+    public void setCanceledAt(LocalDateTime canceledAt) {
+        this.canceledAt = canceledAt;
+    }
+
+    public LocalDateTime getCheckinAt() {
+        return checkinAt;
+    }
+
+    public void setCheckinAt(LocalDateTime checkinAt) {
+        this.checkinAt = checkinAt;
+    }
+}

backend/src/main/java/com/community/app/entity/Activity.java

@@ -0,0 +1,150 @@
+package com.community.app.entity;
+
+import java.time.LocalDateTime;
+
+public class Activity {
+    private Long id;
+    private String title;
+    private String term;
+    private String summary;
+    private String content;
+    private String location;
+    private LocalDateTime startTime;
+    private LocalDateTime endTime;
+    private LocalDateTime signupStart;
+    private LocalDateTime signupEnd;
+    private Integer quota;
+    private String status;
+    private String coverUrl;
+    private Long createdBy;
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getTerm() {
+        return term;
+    }
+
+    public void setTerm(String term) {
+        this.term = term;
+    }
+
+    public String getSummary() {
+        return summary;
+    }
+
+    public void setSummary(String summary) {
+        this.summary = summary;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public String getLocation() {
+        return location;
+    }
+
+    public void setLocation(String location) {
+        this.location = location;
+    }
+
+    public LocalDateTime getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(LocalDateTime startTime) {
+        this.startTime = startTime;
+    }
+
+    public LocalDateTime getEndTime() {
+        return endTime;
+    }
+
+    public void setEndTime(LocalDateTime endTime) {
+        this.endTime = endTime;
+    }
+
+    public LocalDateTime getSignupStart() {
+        return signupStart;
+    }
+
+    public void setSignupStart(LocalDateTime signupStart) {
+        this.signupStart = signupStart;
+    }
+
+    public LocalDateTime getSignupEnd() {
+        return signupEnd;
+    }
+
+    public void setSignupEnd(LocalDateTime signupEnd) {
+        this.signupEnd = signupEnd;
+    }
+
+    public Integer getQuota() {
+        return quota;
+    }
+
+    public void setQuota(Integer quota) {
+        this.quota = quota;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCoverUrl() {
+        return coverUrl;
+    }
+
+    public void setCoverUrl(String coverUrl) {
+        this.coverUrl = coverUrl;
+    }
+
+    public Long getCreatedBy() {
+        return createdBy;
+    }
+
+    public void setCreatedBy(Long createdBy) {
+        this.createdBy = createdBy;
+    }
+
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(LocalDateTime createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public LocalDateTime getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(LocalDateTime updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+}

backend/src/main/java/com/community/app/entity/ActivitySignup.java

@@ -0,0 +1,78 @@
+package com.community.app.entity;
+
+import java.time.LocalDateTime;
+
+public class ActivitySignup {
+    private Long id;
+    private Long activityId;
+    private Long userId;
+    private String status;
+    private String checkinStatus;
+    private LocalDateTime signedAt;
+    private LocalDateTime canceledAt;
+    private LocalDateTime checkinAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getActivityId() {
+        return activityId;
+    }
+
+    public void setActivityId(Long activityId) {
+        this.activityId = activityId;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public String getCheckinStatus() {
+        return checkinStatus;
+    }
+
+    public void setCheckinStatus(String checkinStatus) {
+        this.checkinStatus = checkinStatus;
+    }
+
+    public LocalDateTime getSignedAt() {
+        return signedAt;
+    }
+
+    public void setSignedAt(LocalDateTime signedAt) {
+        this.signedAt = signedAt;
+    }
+
+    public LocalDateTime getCanceledAt() {
+        return canceledAt;
+    }
+
+    public void setCanceledAt(LocalDateTime canceledAt) {
+        this.canceledAt = canceledAt;
+    }
+
+    public LocalDateTime getCheckinAt() {
+        return checkinAt;
+    }
+
+    public void setCheckinAt(LocalDateTime checkinAt) {
+        this.checkinAt = checkinAt;
+    }
+}

backend/src/main/java/com/community/app/entity/User.java

@@ -0,0 +1,80 @@
+package com.community.app.entity;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import java.time.LocalDateTime;
+
+public class User {
+    private Long id;
+    private String username;
+    @JsonIgnore
+    private String passwordHash;
+    private String nickname;
+    private String phone;
+    private String role;
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPasswordHash() {
+        return passwordHash;
+    }
+
+    public void setPasswordHash(String passwordHash) {
+        this.passwordHash = passwordHash;
+    }
+
+    public String getNickname() {
+        return nickname;
+    }
+
+    public void setNickname(String nickname) {
+        this.nickname = nickname;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public String getRole() {
+        return role;
+    }
+
+    public void setRole(String role) {
+        this.role = role;
+    }
+
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(LocalDateTime createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public LocalDateTime getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(LocalDateTime updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+}

backend/src/main/java/com/community/app/mapper/ActivityMapper.java

@@ -0,0 +1,19 @@
+package com.community.app.mapper;
+
+import com.community.app.dto.ActivityView;
+import com.community.app.entity.Activity;
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
+
+public interface ActivityMapper {
+    int insert(Activity activity);
+
+    int update(Activity activity);
+
+    Activity findById(@Param("id") Long id);
+
+    ActivityView findViewById(@Param("id") Long id);
+
+    List<ActivityView> list(@Param("status") String status, @Param("keyword") String keyword);
+}

backend/src/main/java/com/community/app/mapper/SignupMapper.java

@@ -0,0 +1,28 @@
+package com.community.app.mapper;
+
+import com.community.app.dto.AdminSignupView;
+import com.community.app.dto.SignupView;
+import com.community.app.entity.ActivitySignup;
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
+
+public interface SignupMapper {
+    ActivitySignup findByActivityAndUser(@Param("activityId") Long activityId, @Param("userId") Long userId);
+
+    ActivitySignup findById(@Param("id") Long id);
+
+    int insert(ActivitySignup signup);
+
+    int updateStatus(@Param("id") Long id, @Param("status") String status, @Param("canceledAt") java.time.LocalDateTime canceledAt);
+
+    int resign(@Param("id") Long id, @Param("status") String status, @Param("signedAt") java.time.LocalDateTime signedAt);
+
+    int checkin(@Param("id") Long id, @Param("checkinStatus") String checkinStatus, @Param("checkinAt") java.time.LocalDateTime checkinAt);
+
+    long countSignedByActivity(@Param("activityId") Long activityId);
+
+    List<SignupView> listByUser(@Param("userId") Long userId);
+
+    List<AdminSignupView> listByActivity(@Param("activityId") Long activityId);
+}

backend/src/main/java/com/community/app/mapper/UserMapper.java

@@ -0,0 +1,16 @@
+package com.community.app.mapper;
+
+import com.community.app.entity.User;
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
+
+public interface UserMapper {
+    User findById(@Param("id") Long id);
+
+    User findByUsername(@Param("username") String username);
+
+    int insert(User user);
+
+    List<User> listAll();
+}

backend/src/main/java/com/community/app/service/ActivityService.java

@@ -0,0 +1,110 @@
+package com.community.app.service;
+
+import com.community.app.dto.ActivityRequest;
+import com.community.app.dto.ActivityView;
+import com.community.app.entity.Activity;
+import com.community.app.mapper.ActivityMapper;
+import com.community.app.mapper.SignupMapper;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Service
+public class ActivityService {
+    private final ActivityMapper activityMapper;
+    private final SignupMapper signupMapper;
+
+    public ActivityService(ActivityMapper activityMapper, SignupMapper signupMapper) {
+        this.activityMapper = activityMapper;
+        this.signupMapper = signupMapper;
+    }
+
+    public ActivityView getView(Long id) {
+        return activityMapper.findViewById(id);
+    }
+
+    public Activity getEntity(Long id) {
+        return activityMapper.findById(id);
+    }
+
+    public List<ActivityView> list(String status, String keyword) {
+        return activityMapper.list(status, keyword);
+    }
+
+    public Activity create(ActivityRequest request, Long creatorId) {
+        validateTimes(request);
+        Activity activity = new Activity();
+        applyRequest(activity, request);
+        activity.setCreatedBy(creatorId);
+        if (activity.getStatus() == null || activity.getStatus().isEmpty()) {
+            activity.setStatus("draft");
+        }
+        activityMapper.insert(activity);
+        return activity;
+    }
+
+    public void update(Long id, ActivityRequest request) {
+        validateTimes(request);
+        Activity activity = activityMapper.findById(id);
+        if (activity == null) {
+            throw new IllegalStateException("活动不存在");
+        }
+        activity.setId(id);
+        applyRequest(activity, request);
+        if (activity.getStatus() == null || activity.getStatus().isEmpty()) {
+            activity.setStatus("draft");
+        }
+        activityMapper.update(activity);
+    }
+
+    public void publish(Long id) {
+        Activity activity = activityMapper.findById(id);
+        if (activity == null) {
+            throw new IllegalStateException("活动不存在");
+        }
+        activity.setStatus("published");
+        activityMapper.update(activity);
+    }
+
+    public void close(Long id) {
+        Activity activity = activityMapper.findById(id);
+        if (activity == null) {
+            throw new IllegalStateException("活动不存在");
+        }
+        activity.setStatus("closed");
+        activityMapper.update(activity);
+    }
+
+    public long countSigned(Long activityId) {
+        return signupMapper.countSignedByActivity(activityId);
+    }
+
+    private void validateTimes(ActivityRequest request) {
+        LocalDateTime start = request.getStartTime();
+        LocalDateTime end = request.getEndTime();
+        LocalDateTime signupStart = request.getSignupStart();
+        LocalDateTime signupEnd = request.getSignupEnd();
+        if (start != null && end != null && end.isBefore(start)) {
+            throw new IllegalStateException("活动结束时间不能早于开始时间");
+        }
+        if (signupStart != null && signupEnd != null && signupEnd.isBefore(signupStart)) {
+            throw new IllegalStateException("报名结束时间不能早于开始时间");
+        }
+    }
+
+    private void applyRequest(Activity activity, ActivityRequest request) {
+        activity.setTitle(request.getTitle());
+        activity.setTerm(request.getTerm());
+        activity.setSummary(request.getSummary());
+        activity.setContent(request.getContent());
+        activity.setLocation(request.getLocation());
+        activity.setStartTime(request.getStartTime());
+        activity.setEndTime(request.getEndTime());
+        activity.setSignupStart(request.getSignupStart());
+        activity.setSignupEnd(request.getSignupEnd());
+        activity.setQuota(request.getQuota());
+        activity.setStatus(request.getStatus());
+        activity.setCoverUrl(request.getCoverUrl());
+    }
+}

backend/src/main/java/com/community/app/service/SignupService.java

@@ -0,0 +1,93 @@
+package com.community.app.service;
+
+import com.community.app.dto.AdminSignupView;
+import com.community.app.dto.SignupView;
+import com.community.app.entity.Activity;
+import com.community.app.entity.ActivitySignup;
+import com.community.app.mapper.ActivityMapper;
+import com.community.app.mapper.SignupMapper;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Service
+public class SignupService {
+    private final SignupMapper signupMapper;
+    private final ActivityMapper activityMapper;
+
+    public SignupService(SignupMapper signupMapper, ActivityMapper activityMapper) {
+        this.signupMapper = signupMapper;
+        this.activityMapper = activityMapper;
+    }
+
+    public void signup(Long activityId, Long userId) {
+        Activity activity = activityMapper.findById(activityId);
+        if (activity == null) {
+            throw new IllegalStateException("活动不存在");
+        }
+        if (!"published".equals(activity.getStatus())) {
+            throw new IllegalStateException("活动未发布或已结束");
+        }
+        LocalDateTime now = LocalDateTime.now();
+        if (activity.getSignupStart() != null && now.isBefore(activity.getSignupStart())) {
+            throw new IllegalStateException("报名尚未开始");
+        }
+        if (activity.getSignupEnd() != null && now.isAfter(activity.getSignupEnd())) {
+            throw new IllegalStateException("报名已结束");
+        }
+        long count = signupMapper.countSignedByActivity(activityId);
+        if (activity.getQuota() != null && count >= activity.getQuota()) {
+            throw new IllegalStateException("报名名额已满");
+        }
+
+        ActivitySignup existing = signupMapper.findByActivityAndUser(activityId, userId);
+        if (existing == null) {
+            ActivitySignup signup = new ActivitySignup();
+            signup.setActivityId(activityId);
+            signup.setUserId(userId);
+            signup.setStatus("SIGNED");
+            signup.setCheckinStatus("NOT");
+            signup.setSignedAt(now);
+            signupMapper.insert(signup);
+            return;
+        }
+        if ("SIGNED".equals(existing.getStatus())) {
+            throw new IllegalStateException("已报名该活动");
+        }
+        signupMapper.resign(existing.getId(), "SIGNED", now);
+    }
+
+    public void cancel(Long activityId, Long userId) {
+        ActivitySignup existing = signupMapper.findByActivityAndUser(activityId, userId);
+        if (existing == null || !"SIGNED".equals(existing.getStatus())) {
+            throw new IllegalStateException("未找到可取消的报名");
+        }
+        if ("CHECKED".equals(existing.getCheckinStatus())) {
+            throw new IllegalStateException("已签到的报名不可取消");
+        }
+        signupMapper.updateStatus(existing.getId(), "CANCELED", LocalDateTime.now());
+    }
+
+    public void checkin(Long signupId) {
+        ActivitySignup existing = signupMapper.findById(signupId);
+        if (existing == null) {
+            throw new IllegalStateException("报名记录不存在");
+        }
+        if (!"SIGNED".equals(existing.getStatus())) {
+            throw new IllegalStateException("该报名已取消，无法签到");
+        }
+        if ("CHECKED".equals(existing.getCheckinStatus())) {
+            throw new IllegalStateException("已完成签到");
+        }
+        signupMapper.checkin(signupId, "CHECKED", LocalDateTime.now());
+    }
+
+    public List<SignupView> listByUser(Long userId) {
+        return signupMapper.listByUser(userId);
+    }
+
+    public List<AdminSignupView> listByActivity(Long activityId) {
+        return signupMapper.listByActivity(activityId);
+    }
+}

backend/src/main/java/com/community/app/service/UserService.java

@@ -0,0 +1,48 @@
+package com.community.app.service;
+
+import com.community.app.entity.User;
+import com.community.app.mapper.UserMapper;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class UserService {
+    private final UserMapper userMapper;
+    private final BCryptPasswordEncoder encoder = new BCryptPasswordEncoder();
+
+    public UserService(UserMapper userMapper) {
+        this.userMapper = userMapper;
+    }
+
+    public User findById(Long id) {
+        return userMapper.findById(id);
+    }
+
+    public User findByUsername(String username) {
+        return userMapper.findByUsername(username);
+    }
+
+    public User register(String username, String rawPassword, String nickname, String phone) {
+        if (userMapper.findByUsername(username) != null) {
+            throw new IllegalStateException("用户名已存在");
+        }
+        User user = new User();
+        user.setUsername(username);
+        user.setPasswordHash(encoder.encode(rawPassword));
+        user.setNickname(nickname);
+        user.setPhone(phone);
+        user.setRole("user");
+        userMapper.insert(user);
+        return user;
+    }
+
+    public boolean verifyPassword(User user, String rawPassword) {
+        return encoder.matches(rawPassword, user.getPasswordHash());
+    }
+
+    public List<User> listAll() {
+        return userMapper.listAll();
+    }
+}

backend/src/main/resources/application.yml

@@ -0,0 +1,25 @@
+server:
+  port: 8080
+
+spring:
+  datasource:
+    url: jdbc:mysql://localhost:3307/community_activity?useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true
+    username: root
+    password: qq5211314
+    driver-class-name: com.mysql.cj.jdbc.Driver
+  jackson:
+    time-zone: Asia/Shanghai
+    date-format: yyyy-MM-dd HH:mm:ss
+
+mybatis:
+  mapper-locations: classpath:mapper/*.xml
+  configuration:
+    map-underscore-to-camel-case: true
+
+sa-token:
+  token-name: satoken
+  timeout: 2592000
+  is-concurrent: true
+  is-share: true
+  token-style: uuid
+  active-timeout: 1800

backend/src/main/resources/mapper/ActivityMapper.xml

@@ -0,0 +1,92 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.community.app.mapper.ActivityMapper">
+  <resultMap id="ActivityMap" type="com.community.app.entity.Activity">
+    <id column="id" property="id"/>
+    <result column="title" property="title"/>
+    <result column="term" property="term"/>
+    <result column="summary" property="summary"/>
+    <result column="content" property="content"/>
+    <result column="content" property="content"/>
+    <result column="location" property="location"/>
+    <result column="start_time" property="startTime"/>
+    <result column="end_time" property="endTime"/>
+    <result column="signup_start" property="signupStart"/>
+    <result column="signup_end" property="signupEnd"/>
+    <result column="quota" property="quota"/>
+    <result column="status" property="status"/>
+    <result column="cover_url" property="coverUrl"/>
+    <result column="created_by" property="createdBy"/>
+    <result column="created_at" property="createdAt"/>
+    <result column="updated_at" property="updatedAt"/>
+  </resultMap>
+
+  <resultMap id="ActivityViewMap" type="com.community.app.dto.ActivityView">
+    <id column="id" property="id"/>
+    <result column="title" property="title"/>
+    <result column="term" property="term"/>
+    <result column="summary" property="summary"/>
+    <result column="location" property="location"/>
+    <result column="start_time" property="startTime"/>
+    <result column="end_time" property="endTime"/>
+    <result column="signup_start" property="signupStart"/>
+    <result column="signup_end" property="signupEnd"/>
+    <result column="quota" property="quota"/>
+    <result column="status" property="status"/>
+    <result column="cover_url" property="coverUrl"/>
+    <result column="signup_count" property="signupCount"/>
+  </resultMap>
+
+  <insert id="insert" useGeneratedKeys="true" keyProperty="id">
+    insert into activity (title, term, summary, content, location, start_time, end_time,
+      signup_start, signup_end, quota, status, cover_url, created_by, created_at, updated_at)
+    values (#{title}, #{term}, #{summary}, #{content}, #{location}, #{startTime}, #{endTime},
+      #{signupStart}, #{signupEnd}, #{quota}, #{status}, #{coverUrl}, #{createdBy}, now(), now())
+  </insert>
+
+  <update id="update">
+    update activity
+    set title = #{title},
+        term = #{term},
+        summary = #{summary},
+        content = #{content},
+        location = #{location},
+        start_time = #{startTime},
+        end_time = #{endTime},
+        signup_start = #{signupStart},
+        signup_end = #{signupEnd},
+        quota = #{quota},
+        status = #{status},
+        cover_url = #{coverUrl},
+        updated_at = now()
+    where id = #{id}
+  </update>
+
+  <select id="findById" resultMap="ActivityMap">
+    select * from activity where id = #{id}
+  </select>
+
+  <select id="findViewById" resultMap="ActivityViewMap">
+    select a.*, coalesce(sum(case when s.status = 'SIGNED' then 1 else 0 end), 0) as signup_count
+    from activity a
+    left join activity_signup s on a.id = s.activity_id
+    where a.id = #{id}
+    group by a.id
+  </select>
+
+  <select id="list" resultMap="ActivityViewMap">
+    select a.*, coalesce(sum(case when s.status = 'SIGNED' then 1 else 0 end), 0) as signup_count
+    from activity a
+    left join activity_signup s on a.id = s.activity_id
+    <where>
+      <if test="status != null and status != ''">
+        a.status = #{status}
+      </if>
+      <if test="keyword != null and keyword != ''">
+        and (a.title like concat('%', #{keyword}, '%') or a.term like concat('%', #{keyword}, '%'))
+      </if>
+    </where>
+    group by a.id
+    order by a.start_time desc
+  </select>
+</mapper>

backend/src/main/resources/mapper/SignupMapper.xml

@@ -0,0 +1,92 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.community.app.mapper.SignupMapper">
+  <resultMap id="SignupMap" type="com.community.app.entity.ActivitySignup">
+    <id column="id" property="id"/>
+    <result column="activity_id" property="activityId"/>
+    <result column="user_id" property="userId"/>
+    <result column="status" property="status"/>
+    <result column="checkin_status" property="checkinStatus"/>
+    <result column="signed_at" property="signedAt"/>
+    <result column="canceled_at" property="canceledAt"/>
+    <result column="checkin_at" property="checkinAt"/>
+  </resultMap>
+
+  <resultMap id="SignupViewMap" type="com.community.app.dto.SignupView">
+    <id column="id" property="id"/>
+    <result column="activity_id" property="activityId"/>
+    <result column="activity_title" property="activityTitle"/>
+    <result column="term" property="term"/>
+    <result column="location" property="location"/>
+    <result column="start_time" property="startTime"/>
+    <result column="end_time" property="endTime"/>
+    <result column="status" property="status"/>
+    <result column="checkin_status" property="checkinStatus"/>
+    <result column="signed_at" property="signedAt"/>
+    <result column="canceled_at" property="canceledAt"/>
+    <result column="checkin_at" property="checkinAt"/>
+  </resultMap>
+
+  <resultMap id="AdminSignupViewMap" type="com.community.app.dto.AdminSignupView">
+    <id column="id" property="id"/>
+    <result column="activity_id" property="activityId"/>
+    <result column="user_id" property="userId"/>
+    <result column="username" property="username"/>
+    <result column="nickname" property="nickname"/>
+    <result column="phone" property="phone"/>
+    <result column="status" property="status"/>
+    <result column="checkin_status" property="checkinStatus"/>
+    <result column="signed_at" property="signedAt"/>
+    <result column="canceled_at" property="canceledAt"/>
+    <result column="checkin_at" property="checkinAt"/>
+  </resultMap>
+
+  <select id="findByActivityAndUser" resultMap="SignupMap">
+    select * from activity_signup where activity_id = #{activityId} and user_id = #{userId}
+  </select>
+
+  <select id="findById" resultMap="SignupMap">
+    select * from activity_signup where id = #{id}
+  </select>
+
+  <insert id="insert" useGeneratedKeys="true" keyProperty="id">
+    insert into activity_signup (activity_id, user_id, status, checkin_status, signed_at)
+    values (#{activityId}, #{userId}, #{status}, #{checkinStatus}, #{signedAt})
+  </insert>
+
+  <update id="updateStatus">
+    update activity_signup set status = #{status}, canceled_at = #{canceledAt} where id = #{id}
+  </update>
+
+  <update id="resign">
+    update activity_signup set status = #{status}, signed_at = #{signedAt}, canceled_at = null
+    where id = #{id}
+  </update>
+
+  <update id="checkin">
+    update activity_signup set checkin_status = #{checkinStatus}, checkin_at = #{checkinAt}
+    where id = #{id}
+  </update>
+
+  <select id="countSignedByActivity" resultType="long">
+    select count(1) from activity_signup where activity_id = #{activityId} and status = 'SIGNED'
+  </select>
+
+  <select id="listByUser" resultMap="SignupViewMap">
+    select s.id, s.activity_id, a.title as activity_title, a.term, a.location, a.start_time, a.end_time,
+           s.status, s.checkin_status, s.signed_at, s.canceled_at, s.checkin_at
+    from activity_signup s
+    join activity a on s.activity_id = a.id
+    where s.user_id = #{userId}
+    order by s.signed_at desc
+  </select>
+
+  <select id="listByActivity" resultMap="AdminSignupViewMap">
+    select s.id, s.activity_id, s.user_id, u.username, u.nickname, u.phone,
+           s.status, s.checkin_status, s.signed_at, s.canceled_at, s.checkin_at
+    from activity_signup s
+    join sys_user u on s.user_id = u.id
+    where s.activity_id = #{activityId}
+    order by s.signed_at desc
+  </select>
+</mapper>

backend/src/main/resources/mapper/UserMapper.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.community.app.mapper.UserMapper">
+  <resultMap id="UserMap" type="com.community.app.entity.User">
+    <id column="id" property="id"/>
+    <result column="username" property="username"/>
+    <result column="password_hash" property="passwordHash"/>
+    <result column="nickname" property="nickname"/>
+    <result column="phone" property="phone"/>
+    <result column="role" property="role"/>
+    <result column="created_at" property="createdAt"/>
+    <result column="updated_at" property="updatedAt"/>
+  </resultMap>
+
+  <select id="findById" resultMap="UserMap">
+    select * from sys_user where id = #{id}
+  </select>
+
+  <select id="findByUsername" resultMap="UserMap">
+    select * from sys_user where username = #{username}
+  </select>
+
+  <insert id="insert" useGeneratedKeys="true" keyProperty="id">
+    insert into sys_user (username, password_hash, nickname, phone, role, created_at, updated_at)
+    values (#{username}, #{passwordHash}, #{nickname}, #{phone}, #{role}, now(), now())
+  </insert>
+
+  <select id="listAll" resultMap="UserMap">
+    select * from sys_user order by id desc
+  </select>
+</mapper>