feat: upgrade user management demo

2026-03-18 16:43:04 +08:00
parent e8afe9a5f4
commit 00306082fb
9 changed files with 753 additions and 464 deletions
--- a/src/main/java/com/example/demo/controller/UserController.java
+++ b/src/main/java/com/example/demo/controller/UserController.java
@@ -2,6 +2,7 @@ package com.example.demo.controller;

 import com.example.demo.common.ApiResponse;
 import com.example.demo.dto.UserRequest;
+import com.example.demo.dto.UserStatsResponse;
 import com.example.demo.model.User;
 import com.example.demo.service.UserService;
 import jakarta.validation.Valid;
@@ -24,31 +25,38 @@ public class UserController {
        return ApiResponse.ok(userService.findAll());
    }

+    @GetMapping("/stats")
+    public ApiResponse<UserStatsResponse> getUserStats() {
+        return ApiResponse.ok(userService.getStats());
+    }
+
+    @GetMapping("/search")
+    public ApiResponse<List<User>> searchUsers(@RequestParam(required = false) String keyword,
+                                               @RequestParam(required = false) String name) {
+        String term = keyword != null && !keyword.isBlank() ? keyword : name;
+        return ApiResponse.ok(userService.search(term));
+    }
+
    @GetMapping("/{id}")
    public ApiResponse<User> getUserById(@PathVariable Long id) {
        return ApiResponse.ok(userService.findById(id));
    }

    @PostMapping
-    public ApiResponse<User> createUser(@Valid @RequestBody UserRequest req) {
-        User user = new User(null, req.name(), req.email(), req.age());
-        return ApiResponse.ok("创建成功", userService.create(user));
+    public ApiResponse<User> createUser(@Valid @RequestBody UserRequest request) {
+        User user = new User(null, request.name(), request.email(), request.age());
+        return ApiResponse.ok("User created successfully", userService.create(user));
    }

    @PutMapping("/{id}")
-    public ApiResponse<User> updateUser(@PathVariable Long id, @Valid @RequestBody UserRequest req) {
-        User user = new User(id, req.name(), req.email(), req.age());
-        return ApiResponse.ok("更新成功", userService.update(id, user));
+    public ApiResponse<User> updateUser(@PathVariable Long id, @Valid @RequestBody UserRequest request) {
+        User user = new User(id, request.name(), request.email(), request.age());
+        return ApiResponse.ok("User updated successfully", userService.update(id, user));
    }

    @DeleteMapping("/{id}")
    public ApiResponse<Void> deleteUser(@PathVariable Long id) {
        userService.delete(id);
-        return ApiResponse.ok("删除成功", null);
-    }
-
-    @GetMapping("/search")
-    public ApiResponse<List<User>> searchUsers(@RequestParam String name) {
-        return ApiResponse.ok(userService.findByName(name));
+        return ApiResponse.ok("User deleted successfully", null);
    }
 }
--- a/src/main/java/com/example/demo/dto/UserRequest.java
+++ b/src/main/java/com/example/demo/dto/UserRequest.java
@@ -4,16 +4,21 @@ import jakarta.validation.constraints.Email;
 import jakarta.validation.constraints.Max;
 import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;

 public record UserRequest(
-        @NotBlank(message = "姓名不能为空")
+        @NotBlank(message = "Name is required")
+        @Size(max = 40, message = "Name must be at most 40 characters")
        String name,

-        @NotBlank(message = "邮箱不能为空")
-        @Email(message = "邮箱格式不正确")
+        @NotBlank(message = "Email is required")
+        @Email(message = "Email format is invalid")
        String email,

-        @Min(value = 1, message = "年龄最小为 1")
-        @Max(value = 120, message = "年龄最大为 120")
+        @NotNull(message = "Age is required")
+        @Min(value = 1, message = "Age must be at least 1")
+        @Max(value = 120, message = "Age must be at most 120")
        Integer age
-) {}
+) {
+}
--- a/src/main/java/com/example/demo/dto/UserStatsResponse.java
+++ b/src/main/java/com/example/demo/dto/UserStatsResponse.java
@@ -0,0 +1,9 @@
+package com.example.demo.dto;
+
+public record UserStatsResponse(
+        long totalUsers,
+        long adults,
+        long underThirty,
+        double averageAge
+) {
+}
--- a/src/main/java/com/example/demo/exception/DuplicateEmailException.java
+++ b/src/main/java/com/example/demo/exception/DuplicateEmailException.java
@@ -0,0 +1,7 @@
+package com.example.demo.exception;
+
+public class DuplicateEmailException extends RuntimeException {
+    public DuplicateEmailException(String message) {
+        super(message);
+    }
+}
--- a/src/main/java/com/example/demo/exception/GlobalExceptionHandler.java
+++ b/src/main/java/com/example/demo/exception/GlobalExceptionHandler.java
@@ -8,6 +8,7 @@ import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;

+import java.time.Instant;
 import java.util.HashMap;
 import java.util.Map;

@@ -15,24 +16,31 @@ import java.util.Map;
 public class GlobalExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
-    public ResponseEntity<ApiResponse<Void>> handleNotFound(ResourceNotFoundException e) {
+    public ResponseEntity<ApiResponse<Void>> handleNotFound(ResourceNotFoundException exception) {
        return ResponseEntity.status(HttpStatus.NOT_FOUND)
-                .body(ApiResponse.fail(404, e.getMessage()));
+                .body(ApiResponse.fail(404, exception.getMessage()));
+    }
+
+    @ExceptionHandler(DuplicateEmailException.class)
+    public ResponseEntity<ApiResponse<Void>> handleDuplicateEmail(DuplicateEmailException exception) {
+        return ResponseEntity.status(HttpStatus.CONFLICT)
+                .body(ApiResponse.fail(409, exception.getMessage()));
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
-    public ResponseEntity<ApiResponse<Map<String, String>>> handleValidation(MethodArgumentNotValidException e) {
+    public ResponseEntity<ApiResponse<Map<String, String>>> handleValidation(MethodArgumentNotValidException exception) {
        Map<String, String> errors = new HashMap<>();
-        for (FieldError error : e.getBindingResult().getFieldErrors()) {
+        for (FieldError error : exception.getBindingResult().getFieldErrors()) {
            errors.put(error.getField(), error.getDefaultMessage());
        }
+
        return ResponseEntity.badRequest()
-                .body(new ApiResponse<>(400, "参数校验失败", errors, java.time.Instant.now()));
+                .body(new ApiResponse<>(400, "Validation failed", errors, Instant.now()));
    }

    @ExceptionHandler(Exception.class)
-    public ResponseEntity<ApiResponse<Void>> handleAny(Exception e) {
+    public ResponseEntity<ApiResponse<Void>> handleAny(Exception exception) {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
-                .body(ApiResponse.fail(500, "服务器内部错误: " + e.getMessage()));
+                .body(ApiResponse.fail(500, "Unexpected server error"));
    }
 }
--- a/src/main/java/com/example/demo/service/UserService.java
+++ b/src/main/java/com/example/demo/service/UserService.java
@@ -1,65 +1,112 @@
 package com.example.demo.service;

+import com.example.demo.dto.UserStatsResponse;
+import com.example.demo.exception.DuplicateEmailException;
 import com.example.demo.exception.ResourceNotFoundException;
 import com.example.demo.model.User;
 import org.springframework.stereotype.Service;

-import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.Collectors;

@Service
 public class UserService {

-    private final List<User> users = new ArrayList<>();
+    private final List<User> users = new CopyOnWriteArrayList<>();
    private final AtomicLong idGenerator = new AtomicLong(1);

    public UserService() {
-        users.add(new User(idGenerator.getAndIncrement(), "张三", "zhangsan@example.com", 25));
-        users.add(new User(idGenerator.getAndIncrement(), "李四", "lisi@example.com", 30));
-        users.add(new User(idGenerator.getAndIncrement(), "王五", "wangwu@example.com", 28));
+        users.add(new User(idGenerator.getAndIncrement(), "Alice Chen", "alice@example.com", 25));
+        users.add(new User(idGenerator.getAndIncrement(), "Brandon Li", "brandon@example.com", 30));
+        users.add(new User(idGenerator.getAndIncrement(), "Carol Wang", "carol@example.com", 28));
    }

    public List<User> findAll() {
-        return new ArrayList<>(users);
+        return users.stream()
+                .sorted((left, right) -> Long.compare(left.getId(), right.getId()))
+                .collect(Collectors.toList());
    }

    public User findById(Long id) {
        return users.stream()
-                .filter(u -> u.getId().equals(id))
+                .filter(user -> user.getId().equals(id))
                .findFirst()
-                .orElseThrow(() -> new ResourceNotFoundException("用户不存在: id=" + id));
+                .orElseThrow(() -> new ResourceNotFoundException("User not found: id=" + id));
    }

-    public List<User> findByName(String name) {
+    public List<User> search(String keyword) {
+        if (keyword == null || keyword.isBlank()) {
+            return findAll();
+        }
+
+        String normalizedKeyword = keyword.trim().toLowerCase();
        return users.stream()
-                .filter(u -> u.getName().contains(name))
+                .filter(user -> user.getName().toLowerCase().contains(normalizedKeyword)
+                        || user.getEmail().toLowerCase().contains(normalizedKeyword))
+                .sorted((left, right) -> Long.compare(left.getId(), right.getId()))
                .collect(Collectors.toList());
    }

    public User create(User user) {
-        user.setId(idGenerator.getAndIncrement());
-        users.add(user);
-        return user;
+        ensureEmailAvailable(user.getEmail(), null);
+        User normalized = normalize(user, idGenerator.getAndIncrement());
+        users.add(normalized);
+        return normalized;
    }

    public User update(Long id, User user) {
        findById(id);
-        user.setId(id);
-        for (int i = 0; i < users.size(); i++) {
-            if (users.get(i).getId().equals(id)) {
-                users.set(i, user);
-                return user;
+        ensureEmailAvailable(user.getEmail(), id);
+
+        User normalized = normalize(user, id);
+        for (int index = 0; index < users.size(); index++) {
+            if (users.get(index).getId().equals(id)) {
+                users.set(index, normalized);
+                return normalized;
            }
        }
-        throw new ResourceNotFoundException("用户不存在: id=" + id);
+
+        throw new ResourceNotFoundException("User not found: id=" + id);
    }

    public void delete(Long id) {
-        boolean removed = users.removeIf(u -> u.getId().equals(id));
+        boolean removed = users.removeIf(user -> user.getId().equals(id));
        if (!removed) {
-            throw new ResourceNotFoundException("用户不存在: id=" + id);
+            throw new ResourceNotFoundException("User not found: id=" + id);
        }
    }
+
+    public UserStatsResponse getStats() {
+        long totalUsers = users.size();
+        long adults = users.stream().filter(user -> user.getAge() >= 18).count();
+        long underThirty = users.stream().filter(user -> user.getAge() < 30).count();
+        double averageAge = users.stream()
+                .mapToInt(User::getAge)
+                .average()
+                .orElse(0.0);
+
+        return new UserStatsResponse(totalUsers, adults, underThirty, averageAge);
+    }
+
+    private void ensureEmailAvailable(String email, Long currentUserId) {
+        String normalizedEmail = email == null ? "" : email.trim().toLowerCase();
+        boolean exists = users.stream()
+                .anyMatch(user -> user.getEmail().equalsIgnoreCase(normalizedEmail)
+                        && (currentUserId == null || !user.getId().equals(currentUserId)));
+
+        if (exists) {
+            throw new DuplicateEmailException("A user with email " + normalizedEmail + " already exists.");
+        }
+    }
+
+    private User normalize(User user, Long id) {
+        return new User(
+                id,
+                user.getName().trim(),
+                user.getEmail().trim().toLowerCase(),
+                user.getAge()
+        );
+    }
 }