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android/app/src/main/AndroidManifest.xml

@@ -4,12 +4,13 @@
 
     <application
         android:allowBackup="true"
-        android:label="Car Maintenance"
+        android:label="@string/app_name"
         android:icon="@drawable/ic_launcher"
         android:roundIcon="@drawable/ic_launcher"
         android:supportsRtl="true"
         android:usesCleartextTraffic="true"
         android:theme="@style/Theme.CarMaintenance">
+        <activity android:name=".CustomerAppointmentActivity" />
         <activity android:name=".RoleHomeActivity" />
         <activity
             android:name=".LoginActivity"

android/app/src/main/java/com/carmaintenance/ApiService.java

@@ -7,4 +7,19 @@ import retrofit2.http.POST;
 public interface ApiService {
     @POST("auth/login")
     Call<ApiResult<LoginResponse>> login(@Body LoginRequest request);
+
+    @retrofit2.http.GET("customers/user/{userId}")
+    Call<ApiResult<Customer>> getCustomerByUserId(@retrofit2.http.Path("userId") int userId);
+
+    @retrofit2.http.GET("vehicles/customer/{customerId}")
+    Call<ApiResult<java.util.List<Vehicle>>> getVehiclesByCustomerId(@retrofit2.http.Path("customerId") int customerId);
+
+    @retrofit2.http.GET("appointments/customer/{customerId}")
+    Call<ApiResult<java.util.List<Appointment>>> getAppointmentsByCustomerId(@retrofit2.http.Path("customerId") int customerId);
+
+    @retrofit2.http.POST("appointments")
+    Call<ApiResult<Appointment>> createAppointment(@retrofit2.http.Body AppointmentCreateRequest request);
+
+    @retrofit2.http.PUT("appointments/{id}/cancel")
+    Call<ApiResult<Appointment>> cancelAppointment(@retrofit2.http.Path("id") int id);
 }

android/app/src/main/java/com/carmaintenance/Appointment.java

@@ -0,0 +1,44 @@
+package com.carmaintenance;
+
+public class Appointment {
+    private Integer appointmentId;
+    private Integer customerId;
+    private Integer vehicleId;
+    private String serviceType;
+    private String appointmentTime;
+    private String contactPhone;
+    private String description;
+    private String status;
+
+    public Integer getAppointmentId() {
+        return appointmentId;
+    }
+
+    public Integer getCustomerId() {
+        return customerId;
+    }
+
+    public Integer getVehicleId() {
+        return vehicleId;
+    }
+
+    public String getServiceType() {
+        return serviceType;
+    }
+
+    public String getAppointmentTime() {
+        return appointmentTime;
+    }
+
+    public String getContactPhone() {
+        return contactPhone;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+}

android/app/src/main/java/com/carmaintenance/AppointmentAdapter.java

@@ -0,0 +1,79 @@
+package com.carmaintenance;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Button;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class AppointmentAdapter extends RecyclerView.Adapter<AppointmentAdapter.ViewHolder> {
+    public interface OnCancelListener {
+        void onCancel(Appointment appointment);
+    }
+
+    private final List<Appointment> items = new ArrayList<>();
+    private final Map<Integer, Vehicle> vehicleMap;
+    private final OnCancelListener cancelListener;
+
+    public AppointmentAdapter(Map<Integer, Vehicle> vehicleMap, OnCancelListener cancelListener) {
+        this.vehicleMap = vehicleMap;
+        this.cancelListener = cancelListener;
+    }
+
+    public void setItems(List<Appointment> appointments) {
+        items.clear();
+        if (appointments != null) {
+            items.addAll(appointments);
+        }
+        notifyDataSetChanged();
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_appointment, parent, false);
+        return new ViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+        Appointment appointment = items.get(position);
+        Vehicle vehicle = vehicleMap.get(appointment.getVehicleId());
+        String plate = vehicle != null ? vehicle.getLicensePlate() : "-";
+
+        holder.summary.setText(ServiceTypeMapper.toDisplay(appointment.getServiceType()) + " - " + plate);
+        holder.detail.setText(holder.itemView.getContext().getString(R.string.appointment_time_label, appointment.getAppointmentTime()));
+        holder.status.setText(ServiceTypeMapper.statusDisplay(appointment.getStatus()));
+
+        boolean canCancel = "pending".equalsIgnoreCase(appointment.getStatus());
+        holder.cancelButton.setVisibility(canCancel ? View.VISIBLE : View.GONE);
+        holder.cancelButton.setOnClickListener(v -> cancelListener.onCancel(appointment));
+    }
+
+    @Override
+    public int getItemCount() {
+        return items.size();
+    }
+
+    static class ViewHolder extends RecyclerView.ViewHolder {
+        final TextView summary;
+        final TextView detail;
+        final TextView status;
+        final Button cancelButton;
+
+        ViewHolder(@NonNull View itemView) {
+            super(itemView);
+            summary = itemView.findViewById(R.id.appointmentSummary);
+            detail = itemView.findViewById(R.id.appointmentDetail);
+            status = itemView.findViewById(R.id.appointmentStatus);
+            cancelButton = itemView.findViewById(R.id.cancelAppointmentButton);
+        }
+    }
+}

android/app/src/main/java/com/carmaintenance/AppointmentCreateRequest.java

@@ -0,0 +1,20 @@
+package com.carmaintenance;
+
+public class AppointmentCreateRequest {
+    private final Integer customerId;
+    private final Integer vehicleId;
+    private final String serviceType;
+    private final String appointmentTime;
+    private final String contactPhone;
+    private final String description;
+
+    public AppointmentCreateRequest(Integer customerId, Integer vehicleId, String serviceType,
+                                    String appointmentTime, String contactPhone, String description) {
+        this.customerId = customerId;
+        this.vehicleId = vehicleId;
+        this.serviceType = serviceType;
+        this.appointmentTime = appointmentTime;
+        this.contactPhone = contactPhone;
+        this.description = description;
+    }
+}

android/app/src/main/java/com/carmaintenance/Customer.java

@@ -0,0 +1,24 @@
+package com.carmaintenance;
+
+public class Customer {
+    private Integer customerId;
+    private Integer userId;
+    private String realName;
+    private String phone;
+
+    public Integer getCustomerId() {
+        return customerId;
+    }
+
+    public Integer getUserId() {
+        return userId;
+    }
+
+    public String getRealName() {
+        return realName;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+}

android/app/src/main/java/com/carmaintenance/CustomerAppointmentActivity.java

@@ -0,0 +1,306 @@
+package com.carmaintenance;
+
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.view.View;
+import android.widget.ArrayAdapter;
+import android.app.DatePickerDialog;
+import android.app.TimePickerDialog;
+import android.widget.Button;
+import android.widget.DatePicker;
+import android.widget.EditText;
+import android.widget.ProgressBar;
+import android.widget.Spinner;
+import android.widget.TimePicker;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Locale;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class CustomerAppointmentActivity extends AppCompatActivity {
+    private Spinner vehicleSpinner;
+    private Spinner serviceTypeSpinner;
+    private EditText appointmentTimeInput;
+    private EditText contactPhoneInput;
+    private EditText descriptionInput;
+    private ProgressBar progressBar;
+    private AppointmentAdapter adapter;
+    private final Calendar appointmentCalendar = Calendar.getInstance();
+    private final SimpleDateFormat appointmentFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss", Locale.CHINA);
+
+    private final List<Vehicle> vehicles = new ArrayList<>();
+    private final Map<Integer, Vehicle> vehicleMap = new HashMap<>();
+    private Integer customerId;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_customer_appointment);
+
+        vehicleSpinner = findViewById(R.id.vehicleSpinner);
+        serviceTypeSpinner = findViewById(R.id.serviceTypeSpinner);
+        appointmentTimeInput = findViewById(R.id.appointmentTimeInput);
+        contactPhoneInput = findViewById(R.id.contactPhoneInput);
+        descriptionInput = findViewById(R.id.descriptionInput);
+        progressBar = findViewById(R.id.appointmentProgress);
+        Button submitButton = findViewById(R.id.submitAppointmentButton);
+        RecyclerView recyclerView = findViewById(R.id.appointmentRecycler);
+
+        adapter = new AppointmentAdapter(vehicleMap, this::cancelAppointment);
+        recyclerView.setAdapter(adapter);
+
+        serviceTypeSpinner.setAdapter(new ArrayAdapter<>(
+                this,
+                android.R.layout.simple_spinner_dropdown_item,
+                ServiceTypeMapperOptions.getServiceTypes()
+        ));
+
+        appointmentTimeInput.setOnClickListener(v -> openDatePicker());
+        appointmentTimeInput.setOnFocusChangeListener((v, hasFocus) -> {
+            if (hasFocus) {
+                openDatePicker();
+            }
+        });
+
+        submitButton.setOnClickListener(v -> submitAppointment());
+
+        loadCustomerContext();
+    }
+
+    private void loadCustomerContext() {
+        setLoading(true);
+        int userId = new UserSession(this).getUserId();
+        if (userId == 0) {
+            toast(R.string.error_missing_user);
+            setLoading(false);
+            return;
+        }
+
+        ApiClient.getService().getCustomerByUserId(userId).enqueue(new Callback<ApiResult<Customer>>() {
+            @Override
+            public void onResponse(Call<ApiResult<Customer>> call, Response<ApiResult<Customer>> response) {
+                if (!response.isSuccessful() || response.body() == null || response.body().getData() == null) {
+                    toast(R.string.error_load_customer);
+                    setLoading(false);
+                    return;
+                }
+                customerId = response.body().getData().getCustomerId();
+                loadVehiclesAndAppointments();
+            }
+
+            @Override
+            public void onFailure(Call<ApiResult<Customer>> call, Throwable t) {
+                toast(getString(R.string.error_network) + t.getMessage());
+                setLoading(false);
+            }
+        });
+    }
+
+    private void loadVehiclesAndAppointments() {
+        if (customerId == null) {
+            setLoading(false);
+            return;
+        }
+
+        ApiClient.getService().getVehiclesByCustomerId(customerId).enqueue(new Callback<ApiResult<List<Vehicle>>>() {
+            @Override
+            public void onResponse(Call<ApiResult<List<Vehicle>>> call, Response<ApiResult<List<Vehicle>>> response) {
+                vehicles.clear();
+                vehicleMap.clear();
+
+                if (response.isSuccessful() && response.body() != null && response.body().getData() != null) {
+                    vehicles.addAll(response.body().getData());
+                }
+
+                for (Vehicle v : vehicles) {
+                    if (v.getVehicleId() != null) {
+                        vehicleMap.put(v.getVehicleId(), v);
+                    }
+                }
+
+                List<String> labels = new ArrayList<>();
+                labels.add(getString(R.string.select_vehicle));
+                for (Vehicle v : vehicles) {
+                    labels.add(v.getLicensePlate() + " - " + v.getBrand() + " " + v.getModel());
+                }
+                vehicleSpinner.setAdapter(new ArrayAdapter<>(
+                        CustomerAppointmentActivity.this,
+                        android.R.layout.simple_spinner_dropdown_item,
+                        labels
+                ));
+
+                loadAppointments();
+            }
+
+            @Override
+            public void onFailure(Call<ApiResult<List<Vehicle>>> call, Throwable t) {
+                toast(getString(R.string.error_network) + t.getMessage());
+                setLoading(false);
+            }
+        });
+    }
+
+    private void loadAppointments() {
+        if (customerId == null) {
+            setLoading(false);
+            return;
+        }
+        ApiClient.getService().getAppointmentsByCustomerId(customerId).enqueue(new Callback<ApiResult<List<Appointment>>>() {
+            @Override
+            public void onResponse(Call<ApiResult<List<Appointment>>> call, Response<ApiResult<List<Appointment>>> response) {
+                setLoading(false);
+                if (!response.isSuccessful() || response.body() == null) {
+                    toast(R.string.error_load_appointments);
+                    return;
+                }
+                adapter.setItems(response.body().getData());
+            }
+
+            @Override
+            public void onFailure(Call<ApiResult<List<Appointment>>> call, Throwable t) {
+                setLoading(false);
+                toast(getString(R.string.error_network) + t.getMessage());
+            }
+        });
+    }
+
+    private void submitAppointment() {
+        if (customerId == null) {
+            toast(R.string.error_load_customer);
+            return;
+        }
+        if (vehicleSpinner.getSelectedItemPosition() == 0) {
+            toast(R.string.error_select_vehicle);
+            return;
+        }
+
+        String appointmentTime = appointmentTimeInput.getText() != null ? appointmentTimeInput.getText().toString().trim() : "";
+        String contactPhone = contactPhoneInput.getText() != null ? contactPhoneInput.getText().toString().trim() : "";
+        String description = descriptionInput.getText() != null ? descriptionInput.getText().toString().trim() : "";
+
+        if (TextUtils.isEmpty(appointmentTime)) {
+            toast(R.string.error_select_time);
+            return;
+        }
+        if (TextUtils.isEmpty(contactPhone)) {
+            toast(R.string.error_contact_phone);
+            return;
+        }
+
+        Vehicle selectedVehicle = vehicles.get(vehicleSpinner.getSelectedItemPosition() - 1);
+        String serviceType = ServiceTypeMapperOptions.getServiceTypeValue(serviceTypeSpinner.getSelectedItemPosition());
+
+        setLoading(true);
+        AppointmentCreateRequest request = new AppointmentCreateRequest(
+                customerId,
+                selectedVehicle.getVehicleId(),
+                serviceType,
+                appointmentTime,
+                contactPhone,
+                description
+        );
+
+        ApiClient.getService().createAppointment(request).enqueue(new Callback<ApiResult<Appointment>>() {
+            @Override
+            public void onResponse(Call<ApiResult<Appointment>> call, Response<ApiResult<Appointment>> response) {
+                setLoading(false);
+                if (!response.isSuccessful() || response.body() == null || response.body().getCode() != 200) {
+                    toast(R.string.error_submit_appointment);
+                    return;
+                }
+                appointmentTimeInput.setText("");
+                contactPhoneInput.setText("");
+                descriptionInput.setText("");
+                toast(R.string.success_submit_appointment);
+                loadAppointments();
+            }
+
+            @Override
+            public void onFailure(Call<ApiResult<Appointment>> call, Throwable t) {
+                setLoading(false);
+                toast(getString(R.string.error_network) + t.getMessage());
+            }
+        });
+    }
+
+    private void cancelAppointment(Appointment appointment) {
+        if (appointment.getAppointmentId() == null) {
+            return;
+        }
+        setLoading(true);
+        ApiClient.getService().cancelAppointment(appointment.getAppointmentId()).enqueue(new Callback<ApiResult<Appointment>>() {
+            @Override
+            public void onResponse(Call<ApiResult<Appointment>> call, Response<ApiResult<Appointment>> response) {
+                setLoading(false);
+                if (!response.isSuccessful() || response.body() == null || response.body().getCode() != 200) {
+                    toast(R.string.error_cancel_appointment);
+                    return;
+                }
+                toast(R.string.success_cancel_appointment);
+                loadAppointments();
+            }
+
+            @Override
+            public void onFailure(Call<ApiResult<Appointment>> call, Throwable t) {
+                setLoading(false);
+                toast(getString(R.string.error_network) + t.getMessage());
+            }
+        });
+    }
+
+    private void setLoading(boolean loading) {
+        progressBar.setVisibility(loading ? View.VISIBLE : View.GONE);
+    }
+
+    private void openDatePicker() {
+        DatePickerDialog dialog = new DatePickerDialog(
+                this,
+                (DatePicker view, int year, int month, int dayOfMonth) -> {
+                    appointmentCalendar.set(Calendar.YEAR, year);
+                    appointmentCalendar.set(Calendar.MONTH, month);
+                    appointmentCalendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
+                    openTimePicker();
+                },
+                appointmentCalendar.get(Calendar.YEAR),
+                appointmentCalendar.get(Calendar.MONTH),
+                appointmentCalendar.get(Calendar.DAY_OF_MONTH)
+        );
+        dialog.show();
+    }
+
+    private void openTimePicker() {
+        TimePickerDialog dialog = new TimePickerDialog(
+                this,
+                (TimePicker view, int hourOfDay, int minute) -> {
+                    appointmentCalendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
+                    appointmentCalendar.set(Calendar.MINUTE, minute);
+                    appointmentCalendar.set(Calendar.SECOND, 0);
+                    appointmentTimeInput.setText(appointmentFormat.format(appointmentCalendar.getTime()));
+                },
+                appointmentCalendar.get(Calendar.HOUR_OF_DAY),
+                appointmentCalendar.get(Calendar.MINUTE),
+                true
+        );
+        dialog.show();
+    }
+
+    private void toast(int resId) {
+        Toast.makeText(this, resId, Toast.LENGTH_SHORT).show();
+    }
+
+    private void toast(String text) {
+        Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
+    }
+}

android/app/src/main/java/com/carmaintenance/LoginActivity.java

@@ -41,7 +41,7 @@ public class LoginActivity extends AppCompatActivity {
         String password = textOf(passwordInput);
 
         if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
-            showError("Username and password are required.");
+            showError(getString(R.string.error_required));
             return;
         }
 
@@ -54,13 +54,13 @@ public class LoginActivity extends AppCompatActivity {
                 setLoading(false);
 
                 if (!response.isSuccessful() || response.body() == null) {
-                    showError("Login failed. Please try again.");
+                    showError(getString(R.string.error_login_failed));
                     return;
                 }
 
                 ApiResult<LoginResponse> result = response.body();
                 if (result.getCode() != 200 || result.getData() == null) {
-                    showError(result.getMessage() != null ? result.getMessage() : "Login failed.");
+                    showError(result.getMessage() != null ? result.getMessage() : getString(R.string.error_login_failed));
                     return;
                 }
 
@@ -69,6 +69,10 @@ public class LoginActivity extends AppCompatActivity {
 
                 String role = data.getUserInfo() != null ? data.getUserInfo().getRole() : "unknown";
                 String displayName = data.getUserInfo() != null ? data.getUserInfo().getUsername() : username;
+                int userId = data.getUserInfo() != null && data.getUserInfo().getUserId() != null
+                        ? data.getUserInfo().getUserId()
+                        : 0;
+                new UserSession(LoginActivity.this).save(userId, displayName, role);
 
                 Intent intent = new Intent(LoginActivity.this, RoleHomeActivity.class);
                 intent.putExtra("role", role);
@@ -80,7 +84,7 @@ public class LoginActivity extends AppCompatActivity {
             @Override
             public void onFailure(Call<ApiResult<LoginResponse>> call, Throwable t) {
                 setLoading(false);
-                showError("Network error: " + t.getMessage());
+                showError(getString(R.string.error_network) + t.getMessage());
             }
         });
     }

android/app/src/main/java/com/carmaintenance/RoleHomeActivity.java

@@ -28,24 +28,36 @@ public class RoleHomeActivity extends AppCompatActivity {
             username = "user";
         }
 
-        userInfo.setText("Welcome " + username + " (" + role + ")");
+        userInfo.setText(getString(R.string.welcome_format, username, role));
 
         if ("admin".equalsIgnoreCase(role)) {
-            primaryAction.setText("Manage Users");
-            secondaryAction.setText("Manage Orders");
+            primaryAction.setText(R.string.role_admin_primary);
+            secondaryAction.setText(R.string.role_admin_secondary);
+            primaryAction.setOnClickListener(v -> {});
+            secondaryAction.setOnClickListener(v -> {});
         } else if ("staff".equalsIgnoreCase(role)) {
-            primaryAction.setText("Search Vehicles");
-            secondaryAction.setText("Parts Lookup");
+            primaryAction.setText(R.string.role_staff_primary);
+            secondaryAction.setText(R.string.role_staff_secondary);
+            primaryAction.setOnClickListener(v -> {});
+            secondaryAction.setOnClickListener(v -> {});
         } else {
-            primaryAction.setText("My Vehicles");
-            secondaryAction.setText("My Appointments");
+            primaryAction.setText(R.string.role_customer_primary);
+            secondaryAction.setText(R.string.role_customer_secondary);
+            primaryAction.setOnClickListener(v -> openCustomerAppointment());
+            secondaryAction.setOnClickListener(v -> openCustomerAppointment());
         }
 
         logoutButton.setOnClickListener(v -> {
             new TokenStore(RoleHomeActivity.this).clear();
+            new UserSession(RoleHomeActivity.this).clear();
             Intent intent = new Intent(RoleHomeActivity.this, LoginActivity.class);
             intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
             startActivity(intent);
         });
     }
+
+    private void openCustomerAppointment() {
+        Intent intent = new Intent(RoleHomeActivity.this, CustomerAppointmentActivity.class);
+        startActivity(intent);
+    }
 }

android/app/src/main/java/com/carmaintenance/ServiceTypeMapper.java

@@ -0,0 +1,39 @@
+package com.carmaintenance;
+
+public class ServiceTypeMapper {
+    public static String toDisplay(String serviceType) {
+        if (serviceType == null) {
+            return "未知服务";
+        }
+        switch (serviceType) {
+            case "maintenance":
+                return "保养";
+            case "repair":
+                return "维修";
+            case "beauty":
+                return "美容";
+            case "insurance":
+                return "保险";
+            default:
+                return serviceType;
+        }
+    }
+
+    public static String statusDisplay(String status) {
+        if (status == null) {
+            return "状态：未知";
+        }
+        switch (status) {
+            case "pending":
+                return "状态：待确认";
+            case "confirmed":
+                return "状态：已确认";
+            case "completed":
+                return "状态：已完成";
+            case "cancelled":
+                return "状态：已取消";
+            default:
+                return "状态：" + status;
+        }
+    }
+}

android/app/src/main/java/com/carmaintenance/ServiceTypeMapperOptions.java

@@ -0,0 +1,30 @@
+package com.carmaintenance;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ServiceTypeMapperOptions {
+    public static List<String> getServiceTypes() {
+        List<String> list = new ArrayList<>();
+        list.add("保养");
+        list.add("维修");
+        list.add("美容");
+        list.add("保险");
+        return list;
+    }
+
+    public static String getServiceTypeValue(int position) {
+        switch (position) {
+            case 0:
+                return "maintenance";
+            case 1:
+                return "repair";
+            case 2:
+                return "beauty";
+            case 3:
+                return "insurance";
+            default:
+                return "maintenance";
+        }
+    }
+}

android/app/src/main/java/com/carmaintenance/UserSession.java

@@ -0,0 +1,45 @@
+package com.carmaintenance;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+public class UserSession {
+    private static final String PREFS_NAME = "auth_prefs";
+    private static final String KEY_USER_ID = "user_id";
+    private static final String KEY_USERNAME = "username";
+    private static final String KEY_ROLE = "role";
+
+    private final SharedPreferences preferences;
+
+    public UserSession(Context context) {
+        this.preferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
+    }
+
+    public void save(int userId, String username, String role) {
+        preferences.edit()
+                .putInt(KEY_USER_ID, userId)
+                .putString(KEY_USERNAME, username)
+                .putString(KEY_ROLE, role)
+                .apply();
+    }
+
+    public int getUserId() {
+        return preferences.getInt(KEY_USER_ID, 0);
+    }
+
+    public String getUsername() {
+        return preferences.getString(KEY_USERNAME, "");
+    }
+
+    public String getRole() {
+        return preferences.getString(KEY_ROLE, "");
+    }
+
+    public void clear() {
+        preferences.edit()
+                .remove(KEY_USER_ID)
+                .remove(KEY_USERNAME)
+                .remove(KEY_ROLE)
+                .apply();
+    }
+}

android/app/src/main/java/com/carmaintenance/Vehicle.java

@@ -0,0 +1,24 @@
+package com.carmaintenance;
+
+public class Vehicle {
+    private Integer vehicleId;
+    private String licensePlate;
+    private String brand;
+    private String model;
+
+    public Integer getVehicleId() {
+        return vehicleId;
+    }
+
+    public String getLicensePlate() {
+        return licensePlate;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+
+    public String getModel() {
+        return model;
+    }
+}

android/app/src/main/res/layout/activity_customer_appointment.xml

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:padding="16dp">
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/appointment_title"
+            android:textSize="20sp"
+            android:textStyle="bold" />
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="@string/appointment_form_title"
+            android:textStyle="bold" />
+
+        <Spinner
+            android:id="@+id/vehicleSpinner"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp" />
+
+        <Spinner
+            android:id="@+id/serviceTypeSpinner"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp" />
+
+        <EditText
+            android:id="@+id/appointmentTimeInput"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:hint="@string/appointment_time_hint"
+            android:inputType="none"
+            android:focusable="false"
+            android:clickable="true" />
+
+        <EditText
+            android:id="@+id/contactPhoneInput"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:hint="@string/contact_phone"
+            android:inputType="phone" />
+
+        <EditText
+            android:id="@+id/descriptionInput"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:hint="@string/appointment_description"
+            android:minLines="2"
+            android:inputType="textMultiLine" />
+
+        <Button
+            android:id="@+id/submitAppointmentButton"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="@string/submit_appointment" />
+
+        <ProgressBar
+            android:id="@+id/appointmentProgress"
+            style="?android:attr/progressBarStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:layout_marginTop="12dp"
+            android:visibility="gone" />
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:text="@string/appointment_list_title"
+            android:textStyle="bold" />
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/appointmentRecycler"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
+    </LinearLayout>
+</ScrollView>

android/app/src/main/res/layout/activity_login.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
@@ -10,7 +10,7 @@
         android:id="@+id/title"
         android:layout_width="0dp"
         android:layout_height="wrap_content"
-        android:text="Car Maintenance"
+        android:text="@string/login_title"
         android:textSize="24sp"
         android:textStyle="bold"
         app:layout_constraintTop_toTopOf="parent"

android/app/src/main/res/layout/activity_role_home.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
@@ -10,7 +10,7 @@
         android:id="@+id/welcomeTitle"
         android:layout_width="0dp"
         android:layout_height="wrap_content"
-        android:text="Role Home"
+        android:text="@string/welcome_title"
         android:textSize="22sp"
         android:textStyle="bold"
         app:layout_constraintTop_toTopOf="parent"
@@ -32,7 +32,7 @@
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_marginTop="24dp"
-        android:text="Primary Action"
+        android:text="@string/primary_action"
         app:layout_constraintTop_toBottomOf="@id/userInfo"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />
@@ -42,7 +42,7 @@
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_marginTop="12dp"
-        android:text="Secondary Action"
+        android:text="@string/secondary_action"
         app:layout_constraintTop_toBottomOf="@id/primaryAction"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />

android/app/src/main/res/layout/item_appointment.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:layout_marginBottom="8dp"
+    app:cardElevation="2dp"
+    app:cardUseCompatPadding="true">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:padding="12dp">
+
+        <TextView
+            android:id="@+id/appointmentSummary"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:textStyle="bold" />
+
+        <TextView
+            android:id="@+id/appointmentDetail"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="4dp" />
+
+        <TextView
+            android:id="@+id/appointmentStatus"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="4dp" />
+
+        <Button
+            android:id="@+id/cancelAppointmentButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:text="@string/cancel_appointment" />
+    </LinearLayout>
+</androidx.cardview.widget.CardView>

android/app/src/main/res/values/strings.xml

@@ -1,8 +1,42 @@
 <resources>
-    <string name="app_name">Car Maintenance</string>
-    <string name="login">Login</string>
-    <string name="username">Username</string>
-    <string name="password">Password</string>
-    <string name="role_home">Role Home</string>
-    <string name="logout">Logout</string>
+    <string name="app_name">车管家</string>
+    <string name="login">登录</string>
+    <string name="username">用户名</string>
+    <string name="password">密码</string>
+    <string name="role_home">角色主页</string>
+    <string name="logout">退出登录</string>
+    <string name="welcome_title">角色主页</string>
+    <string name="login_title">车管家</string>
+    <string name="primary_action">主要功能</string>
+    <string name="secondary_action">次要功能</string>
+    <string name="error_required">请输入用户名和密码</string>
+    <string name="error_login_failed">登录失败，请重试</string>
+    <string name="error_network">网络错误：</string>
+    <string name="role_admin_primary">用户管理</string>
+    <string name="role_admin_secondary">工单管理</string>
+    <string name="role_staff_primary">车辆查询</string>
+    <string name="role_staff_secondary">配件查询</string>
+    <string name="role_customer_primary">我的车辆</string>
+    <string name="role_customer_secondary">在线预约</string>
+    <string name="welcome_format">欢迎 %1$s（%2$s）</string>
+    <string name="appointment_title">在线预约</string>
+    <string name="appointment_form_title">提交预约</string>
+    <string name="appointment_list_title">我的预约</string>
+    <string name="appointment_time_hint">请选择预约时间</string>
+    <string name="contact_phone">联系电话</string>
+    <string name="appointment_description">预约说明</string>
+    <string name="submit_appointment">提交预约</string>
+    <string name="cancel_appointment">取消预约</string>
+    <string name="select_vehicle">请选择车辆</string>
+    <string name="appointment_time_label">预约时间：%1$s</string>
+    <string name="error_missing_user">用户信息缺失，请重新登录</string>
+    <string name="error_load_customer">获取客户信息失败</string>
+    <string name="error_load_appointments">加载预约失败</string>
+    <string name="error_select_vehicle">请选择车辆</string>
+    <string name="error_select_time">请选择预约时间</string>
+    <string name="error_contact_phone">请输入联系电话</string>
+    <string name="error_submit_appointment">预约提交失败</string>
+    <string name="success_submit_appointment">预约成功</string>
+    <string name="error_cancel_appointment">取消预约失败</string>
+    <string name="success_cancel_appointment">预约已取消</string>
 </resources>