EDUCODER头哥 SpringBoot 异常处理

极速版：

@ExceptionHandle 注解处理异常

java 复制代码

package net.educoder.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class Step1Controller {
    /**
     * 模拟 NullPointerException
     *
     * @return
     */
    @RequestMapping("/step1_1")
    public String showInfo() {
        String str = null;
        str.length();
        return "index";
    }

    /**
     * 模拟 ArithmeticException
     *
     * @return
     */
    @RequestMapping("/step1_2")
    public String showInfo2() {
        int a = 10 / 0;
        return "index";
    }


    /********** begin **********/


    /**
     * java.lang.ArithmeticException 异常处理器
     * <p>
     * 需求：
     * 1.捕捉该 Controller 类下的所有算术异常
     * 2.跳转 error1.html 页面
     */
    @ExceptionHandler(value = {java.lang.ArithmeticException.class})
    public String ArithmeticException() {
        return "error1";
    }
   
   


    /**
     * java.lang.NullPointerException 异常处理器
     * <p>
     * 需求：
     * 1.捕捉该 Controller 类下的所有空指针异常
     * 2.跳转 error2.html 页面
     */
    @ExceptionHandler(value = {java.lang.NullPointerException.class})
    public String NullPointerException() {
        return "error2";
    }
   
   

    /********** end **********/
}

@ControllerAdvice 注解处理异常

java 复制代码

package net.educoder.conf;

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;

/********** begin **********/

@ControllerAdvice
public class Step2Exception {


    /**
     * 需求：
     * 1.定义全局算术异常处理器，返回格式为：{"msg":"算术异常","code":-1}
     * 2.定义全局空指针异常处理器，返回格式为：{"msg":"空指针异常","code":-2}
     */
    @ResponseBody
    @ExceptionHandler(value = ArithmeticException.class)
    public Map<String, Object> ArithmeticExceptionHandler(Exception ex) {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("code", -1);
        map.put("msg", "算术异常");
        return map;
    }
    
    @ResponseBody
    @ExceptionHandler(value = NullPointerException.class)
    public Map<String, Object> NullPointerExceptionHandler(Exception ex) {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("code", -2);
        map.put("msg", "空指针异常");
        return map;
    }
   

    /********** end **********/
}

自定义 HandlerExceptionResolver 类处理异常

java 复制代码

package net.educoder.conf;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

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

@Configuration
public class GlobalException implements HandlerExceptionResolver {

    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest
            , HttpServletResponse httpServletResponse
            , Object o, Exception ex) {
        ModelAndView mv = new ModelAndView();

        /**
         * 需求：判断异常类型，如果异常类型为 ArithmeticException 页面跳转到 error1.html ，如果异常类型为 NullPointerException 页面跳转到 error2.html
         */
        /********** begin **********/
        if (ex instanceof ArithmeticException) {
            mv.setViewName("error1");
        }else{
            mv.setViewName("error2");
        }

        /********** end **********/
        return mv;
    }
}

以下是题目

@ExceptionHandle 注解处理异常

任务描述

本关任务：@ExceptionHandle 注解进行异常处理。