170621、springboot编程之全局异常捕获

1、创建GlobalExceptionHandler.java，在类上注解@ControllerAdvice，在方法上注解@ExceptionHandler(value = Exception.class)，Exception.class表示拦截所有的异常信息

package com.rick.common.handler;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.util.IOUtils;
import com.rick.common.ResultJson;
import com.rick.common.exception.BusinessException;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(value = Exception.class)
    public ModelAndView defaultErrorHandler(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex){
        response.setContentType(MediaType.APPLICATION_JSON_UTF8_VALUE);
        System.out.println("=====================全局异常信息捕获=======================");

        String msg;
        if(ex instanceof BusinessException){
            msg = ex.getMessage();
        } else {
            msg = "操作异常!";
        }
        ex.printStackTrace();
        PrintWriter out = null;
        try {
            out = response.getWriter();
            out.print(JSON.toJSON(ResultJson.buildFailInstance(msg)).toString());
        } catch(Exception e){
            e.printStackTrace();
        } finally {
            IOUtils.close(out);
        }

        return null;
    }
}

2、测试异常信息，在 HelloController.java中制造异常信息

@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String hello(){
        System.out.println(1/0);//制造异常信息
        return "Hello World!";
    }
}

3、效果展示

访问http://localhost:8080/hello，后台抛出异常信息

页面展示效果