自定义异常处理可以帮助我们更好地管理应用程序中的异常，并返回统一的错误响应。
1. 自定义异常类
定义自己的异常类，继承自 RuntimeException 或其他异常类。
public class MyException extends RuntimeException {private String msg;public MyException(String msg) {super(msg);this.msg = msg;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}
}2. 使用 @ControllerAdvice 和 @ExceptionHandler
@ControllerAdvice 是一个全局的异常处理类，它可以处理整个应用程序中抛出的异常。@ExceptionHandler 用于指定处理特定异常的方法。
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;@ControllerAdvice
public class MyExceptionHandler {@ExceptionHandler(MyException.class)public ResponseEntity<String> MyExceptionHandle(Exception e){return new ResponseEntity<String>(e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);}@ExceptionHandler(Exception.class)public ResponseEntity<String> exceptionHandle(Exception e){e.printStackTrace();return new ResponseEntity<String>(e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);}}
3. 创建控制器类，在 Controller 中抛出异常
import com.qvtu.web.exception.MyException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
@RequestMapping("/dish")
public class DishController {@RequestMapping("/del/{i}")public ResponseEntity<String> delDish(@PathVariable String i) {Integer id=Integer.valueOf(i);if (id<0){throw new MyException("参数错误！");}return new ResponseEntity<>("del success", HttpStatus.OK);}
}
4. 运行测试
启动程序，在浏览器中访问http://localhost:8080/dish/del/1
在浏览器中访问http://localhost:8080/dish/del/-1
在浏览器中访问http://localhost:8080/dish/del/a
