feat: 全局异常

pom.xml

@@ -36,6 +36,12 @@
             <scope>test</scope>
         </dependency>
 
+        <!-- Bean Validation -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+
         <!-- Spring Data JPA -->
         <dependency>
             <groupId>org.springframework.boot</groupId>

src/main/java/com/example/demo/controller/UserController.java

@@ -6,6 +6,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
+import javax.validation.Valid;
 import java.util.List;
 
 @RestController
@@ -28,12 +29,12 @@ public class UserController {
     }
 
     @PostMapping
-    public User create(@RequestBody User user) {
+    public User create(@Valid @RequestBody User user) {
         return userService.save(user);
     }
 
     @PutMapping("/{id}")
-    public ResponseEntity<User> update(@PathVariable Long id, @RequestBody User user) {
+    public ResponseEntity<User> update(@PathVariable Long id, @Valid @RequestBody User user) {
         return userService.findById(id)
                 .map(existing -> {
                     existing.setName(user.getName());

src/main/java/com/example/demo/entity/User.java

@@ -1,6 +1,9 @@
 package com.example.demo.entity;
 
 import javax.persistence.*;
+import javax.validation.constraints.Email;
+import javax.validation.constraints.Min;
+import javax.validation.constraints.NotBlank;
 
 @Entity
 @Table(name = "t_user")
@@ -10,12 +13,16 @@ public class User {
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
+    @NotBlank(message = "姓名不能为空")
     @Column(nullable = false)
     private String name;
 
+    @NotBlank(message = "邮箱不能为空")
+    @Email(message = "邮箱格式不正确")
     @Column(nullable = false)
     private String email;
 
+    @Min(value = 0, message = "年龄不能小于0")
     private Integer age;
 
     public User() {

src/main/java/com/example/demo/exception/BusinessException.java

@@ -0,0 +1,22 @@
+package com.example.demo.exception;
+
+/**
+ * 业务异常
+ */
+public class BusinessException extends RuntimeException {
+
+    private final int code;
+
+    public BusinessException(int code, String message) {
+        super(message);
+        this.code = code;
+    }
+
+    public BusinessException(String message) {
+        this(400, message);
+    }
+
+    public int getCode() {
+        return code;
+    }
+}

src/main/java/com/example/demo/exception/GlobalExceptionHandler.java

@@ -0,0 +1,60 @@
+package com.example.demo.exception;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import javax.servlet.http.HttpServletRequest;
+import java.time.LocalDateTime;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);
+
+    /**
+     * 处理参数校验失败
+     */
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<Map<String, Object>> handleValidation(MethodArgumentNotValidException ex) {
+        String message = ex.getBindingResult().getFieldErrors().stream()
+                .map(FieldError::getDefaultMessage)
+                .collect(Collectors.joining("; "));
+        return buildResponse(HttpStatus.BAD_REQUEST, message);
+    }
+
+    /**
+     * 处理业务异常
+     */
+    @ExceptionHandler(BusinessException.class)
+    public ResponseEntity<Map<String, Object>> handleBusiness(BusinessException ex) {
+        log.warn("业务异常: code={}, message={}", ex.getCode(), ex.getMessage());
+        return buildResponse(HttpStatus.valueOf(ex.getCode()), ex.getMessage());
+    }
+
+    /**
+     * 处理其他未捕获异常
+     */
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<Map<String, Object>> handleException(Exception ex, HttpServletRequest request) {
+        log.error("请求 {} {} 发生异常", request.getMethod(), request.getRequestURI(), ex);
+        return buildResponse(HttpStatus.INTERNAL_SERVER_ERROR, "服务器内部错误");
+    }
+
+    private ResponseEntity<Map<String, Object>> buildResponse(HttpStatus status, String message) {
+        Map<String, Object> body = new LinkedHashMap<>();
+        body.put("timestamp", LocalDateTime.now().toString());
+        body.put("status", status.value());
+        body.put("error", status.getReasonPhrase());
+        body.put("message", message);
+        return ResponseEntity.status(status).body(body);
+    }
+}