从零搭建SpringBoot后台框架(四)——全局异常处理

一、为什么要处理全局异常

如下，当系统出现异常时，返回系统默认的错误信息，不是和前端约定的标准数据格式，给前端统一逻辑处理带来困难

{
    "timestamp": "2023-10-09T05:50:47.644+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "path": "/userInfo/testException"
}

二、添加业务异常类

package com.example.demo.common.http;

public class BusinessException extends RuntimeException {
    public BusinessException(String msg) {
        super(msg);
    }
}

三、配置全局异常处理类

1. RestCode下添加枚举BUSINESS_EXCEPTION("999998", "业务异常"),

2. RestResult添加默认无参构造函数

public RestResult() {

}

3. 添加全局异常处理类

package com.example.demo.common.http;

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(BusinessException.class)
    public RestResult handleBusinessException(BusinessException e) {
        e.printStackTrace();
        return new RestResult().setCode(RestCode.BUSINESS_EXCEPTION.getCode()).setMsg(e.getMessage());
    }

    @ExceptionHandler(Exception.class)
    public RestResult<String> handleException(Exception e) {
        e.printStackTrace();
        return new RestResult().setCode(RestCode.FAIL.getCode()).setMsg(e.getMessage());
    }
}

对业务异常统一拦截，返回错误码为"999998",对于其他异常，返回错误码为"999999"

四、功能验证

package com.example.demo.controller;

import com.example.demo.common.http.BusinessException;
import com.example.demo.common.http.RestResult;
import com.example.demo.model.UserInfo;
import com.example.demo.service.UserInfoService;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
@RequestMapping("userInfo")
public class UserInfoController {
    @Resource
    private UserInfoService userInfoService;

    @PostMapping("/selectById")
    public RestResult<UserInfo> selectById(Long id) {
        UserInfo userInfo = userInfoService.selectById(id);
        if (null == userInfo) {
            throw new BusinessException("用户不存在");
        }
        return RestResult.getSuccessResult(userInfo);
    }

    @PostMapping("/testException")
    public RestResult<UserInfo> testException(Long id) {
        UserInfo userInfo = null;
        userInfo.getId();
        return RestResult.getSuccessResult();
    }
}

访问http://localhost:8080/userInfo/selectById?id=3返回

{
    "code": "999998",
    "msg": "用户不存在",
    "data": null
}

访问http://localhost:8080/userInfo/testException?id=3返回

{
    "code": "999999",
    "msg": null,
    "data": null
}

五、项目地址

gitee

PS:可以通过tag下载本文对应的代码版本

六、结尾

全局异常处理已完成，有问题可以联系chenzhenlindx@qq.com

七、参考文章

1. 从零搭建自己的SpringBoot后台框架(五)