Springboot：统一异常处理

1. 实现思路：

1. 需要配合@ExceptionHandler使用。
2. 当将异常抛到controller时,可以对异常进行统一处理,规定返回的json格式或是跳转到一个错误页面

2. 首先创建全局异常捕捉处理类：GlobleExceptionHandler.java

package com.ieslab.powergrid.demosvr.utils;

import com.ieslab.powergrid.demosvr.entity.MyException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.HashMap;
import java.util.Map;

/** <p>Title: GlobleExceptionHandler </p>
 * <p>Description: 全局异常捕捉处理</p>
 *
 * @author houpeibin
 * @date 2020-2-20 下午7:15:30
 * @version V1.0
 */
@ControllerAdvice
public class GlobleExceptionHandler {

    @ResponseBody
    @ExceptionHandler(value = Exception.class)
    public Map errorHandler(Exception ex) {
        Map map = new HashMap();
        map.put("code", 400);
        //判断异常的类型,返回不一样的返回值
        if(ex instanceof MissingServletRequestParameterException){
            map.put("msg","缺少必需参数："+((MissingServletRequestParameterException) ex).getParameterName());
        }
        else if(ex instanceof MyException){
            map.put("msg","这是自定义异常");
        }
        return map;
    }
}

3.创建自定义异常类：MyException.java

package com.ieslab.powergrid.demosvr.entity;

import lombok.Data;
import org.springframework.web.bind.annotation.RestController;

//自定义异常类
@Data
public class MyException extends RuntimeException {
    private long code;
    private String msg;

    public MyException(Long code, String msg){
        super(msg);
        this.code = code;
        this.msg = msg;
    }

    public MyException(String msg){
        super(msg);
        this.msg = msg;
    }
}

4.创建TestController.java

package com.ieslab.powergrid.demosvr.controller;

import com.ieslab.powergrid.demosvr.entity.MyException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/** <p>Title: TestController </p>
 * <p>Description: 测试全局异常捕获功能</p>
 *
 * @author houpeibin
 * @date 2020-2-20 下午7:15:30
 * @version V1.0
 */
@RestController
public class TestController {
    @RequestMapping("testException")
    public String testException() throws Exception{
        throw new MissingServletRequestParameterException("name","String");
    }

    @RequestMapping("testMyException")
    public String testMyException() throws MyException {
        throw new MyException("i am a myException");
    }
}

这个controller类型中，定义了两个方法，都是直接抛出异常，看看是否能够被统一异常类捕获，请运行程序后访问：http://localhost:8080/testException

访问：http://localhost:8080/testMyException

5.总结

统一异常处理集成完毕，是不是很简单？？？