SpringBoot2系列——全局异常处理

前言

• 本文只做记录，不做具体源码解析。
• 博主也是初学，系列文章只做入门，不建议当做范文。

代码实现

项目结构

• GlobalException.java是全局异常处理类
• MyJwtException.java是自定义的异常处理类

GlobalException.java实现全局异常捕获并返回json。

package com.itheima.boot.exception;

import com.itheima.boot.utils.Resp;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;


@ControllerAdvice
@ResponseBody
@Slf4j
public class GlobalException {
    /**
     * 全局异常捕获
     */
    @ExceptionHandler(Exception.class)
    public Resp exceptionHandler(Exception e) {
        WriteException(e);
        return Resp.error().msg(e.getMessage());

    }

    @ExceptionHandler(MyJwtException.class)
    public Resp JwtExceptionHandler(Exception e) {
        // 获取response重写状态码
        ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        assert requestAttributes != null;
        HttpServletResponse response = requestAttributes.getResponse();
        assert response != null;
        response.setStatus(403);
        // 写异常日志
        WriteException(e);
        return Resp.error().code(40300).msg("token校验失败！");
    }

    /**
     * 把异常写进日志
     */
    private void WriteException(Exception e) {
        StringWriter sw = null;
        PrintWriter pw = null;
        try {
            sw = new StringWriter();
            pw = new PrintWriter(sw);
            e.printStackTrace(pw);
            log.error(sw.toString());
        } finally {
            if (sw != null) {
                try {
                    sw.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
            if (pw != null) {
                pw.close();
            }
        }
    }
}

MyJwtException.java是自定义的异常类，继承RuntimeException实现。

package com.itheima.boot.exception;

public class MyJwtException extends RuntimeException {
    public MyJwtException(String message) {
        super(message);
    }
}

业务中需要的位置抛出MyJwtException

try {
    int a = 10/0;
}catch(Exception e) {
    throw new MyJwtException ("token验证失败");
}