Springboot全局异常处理GlobalExceptionHandler

全局异常处理

自定义异常

在应用开发过程当中，除系统自身的异常外，不一样业务场景中用到的异常也不同，为了与标题 轻松搞定全局异常 更加的贴切，定义个本身的异常，看看如何捕获…

package com.baizhi.exception;

public class CustomException extends RuntimeException {

    private static final long serialVersionUID = 4564124491192825748L;

    private int code;

    public CustomException() {
        super();
    }

    public CustomException(int code, String message) {
        super(message);
        this.setCode(code);
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }
}
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异常信息模板

定义返回的异常信息的格式，这样异常信息风格更为统一

public class ErrorResponseEntity {

    private int code;
    private String message;
    // 省略 get set
}
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异常处理（关键）

注解概述

• @ControllerAdvice 捕获 Controller 层抛出的异常，若是添加 @ResponseBody 返回信息则为JSON格式。
• @RestControllerAdvice 至关于 @ControllerAdvice 与 @ResponseBody 的结合体。
• @ExceptionHandler 统一处理一种类的异常，减小代码重复率，下降复杂度。

建立一个 GlobalExceptionHandler 类，并添加上 @RestControllerAdvice 注解就能够定义出异常通知类了，而后在定义的方法中添加上 @ExceptionHandler 便可实现异常的捕捉…

package com.baizhi.controller;
import com.baizhi.exception.CustomException;
import com.baizhi.exception.ErrorResponseEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.method.annotation.MethodArgumentTypeMismatchException;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


@RestControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {


    /**
     * 定义要捕获的异常 能够多个 @ExceptionHandler({})
     *
     * @param request  request
     * @param e        exception
     * @param response response
     * @return 响应结果
     */
    @ExceptionHandler(CustomException.class)
    public ErrorResponseEntity customExceptionHandler(HttpServletRequest request, final Exception e, HttpServletResponse response) {
        response.setStatus(HttpStatus.BAD_REQUEST.value());
        CustomException exception = (CustomException) e;
        return new ErrorResponseEntity(exception.getCode(), exception.getMessage());
    }

    /**
     * 捕获  RuntimeException 异常
     * TODO  若是你以为在一个 exceptionHandler 经过  if (e instanceof xxxException) 太麻烦
     * TODO  那么你还能够本身写多个不一样的 exceptionHandler 处理不一样异常
     *
     * @param request  request
     * @param e        exception
     * @param response response
     * @return 响应结果
     */
    @ExceptionHandler(RuntimeException.class)
    public ErrorResponseEntity runtimeExceptionHandler(HttpServletRequest request, final Exception e, HttpServletResponse response) {
        response.setStatus(HttpStatus.BAD_REQUEST.value());
        RuntimeException exception = (RuntimeException) e;
        return new ErrorResponseEntity(400, exception.getMessage());
    }

    /**
     * 通用的接口映射异常处理方
     */
    @Override
    protected ResponseEntity<Object> handleExceptionInternal(Exception ex, Object body, HttpHeaders headers,
                                                             HttpStatus status, WebRequest request) {
        if (ex instanceof MethodArgumentNotValidException) {
            MethodArgumentNotValidException exception = (MethodArgumentNotValidException) ex;
            return new ResponseEntity<>(new ErrorResponseEntity(status.value(), exception.getBindingResult().getAllErrors().get(0).getDefaultMessage()), status);
        }
        if (ex instanceof MethodArgumentTypeMismatchException) {
            MethodArgumentTypeMismatchException exception = (MethodArgumentTypeMismatchException) ex;
            logger.error("参数转换失败，方法：" + exception.getParameter().getMethod().getName() + "，参数：" + exception.getName()
                    + ",信息：" + exception.getLocalizedMessage());
            return new ResponseEntity<>(new ErrorResponseEntity(status.value(), "参数转换失败"), status);
        }
        return new ResponseEntity<>(new ErrorResponseEntity(status.value(), "参数转换失败"), status);
    }
}
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