SpringMVC的异常处理（超详细）

﹏ヽ暗。殇╰゛Y 2022-10-28 14:20 223阅读 0赞

### SpringMVC的异常处理 ###

*  异常处理思路
 *  异常处理
 *   *  先看下项目的目录结构
     *  演示程序异常
     *   *  演示效果
     *  异常处理步骤
     *   *  1、自定义异常类
         *  2、自定义异常处理器
         *  3、配置异常处理器
         *  异常处理效果演示

# 异常处理思路 #

> **Controller调用service，service调用dao，异常都是向上抛出的，最终有DispatcherServlet找异常处理器进行异常的处理。**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70]

# 异常处理 #

## 先看下项目的目录结构 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70 1]

## 演示程序异常 ##

**index.jsp：**

<%--
      Created by IntelliJ IDEA.
      User: Keafmd
      Date: 2021/2/6
      Time: 10:11
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
    
        <h1>异常处理</h1>
    
        <a href="user/testException">testException</a>
    
    </body>
    </html>

**UserController类：**

package com.keafmd.controller;
    
    import com.keafmd.exception.SysException;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    import java.sql.SQLOutput;
    
    /** * Keafmd * * @ClassName: UserController * @Description: * @author: 牛哄哄的柯南 * @date: 2021-02-06 10:14 */
    @Controller
    @RequestMapping("/user")
    public class UserController { 
    
        @RequestMapping("testException")
        public String testException() throws Exception{ 
            System.out.println("testException执行了。。。");
            //模拟异常
            int a = 10/0;
            return "success";
        }
    
    }

**success.jsp：**

<%--
      Created by IntelliJ IDEA.
      User: Keafmd
      Date: 2021/1/30
      Time: 15:09
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
        <h1>执行成功</h1>
    </body>
    </html>

> **配置好tomcat后开始执行。**

### 演示效果 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70 2]

> **点击testException后**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70 3]

> **这种显示非常不友好，我们需要处理下异常。**

## 异常处理步骤 ##

### 1、自定义异常类 ###

**SysException：**

package com.keafmd.exception;
    
    /** * Keafmd * * @ClassName: SysException * @Description: 自定义异常类 * @author: 牛哄哄的柯南 * @date: 2021-02-06 10:25 */
    public class SysException extends Exception{ 
    
        //存储提示信息
        private  String message;
    
        public SysException(String message) { 
            this.message = message;
        }
    
        public String getMessage() { 
            return message;
        }
    
        public void setMessage(String message) { 
            this.message = message;
        }
    
    }

### 2、自定义异常处理器 ###

**SysExceptionResolver：**

package com.keafmd.exception;
    
    import org.springframework.web.servlet.HandlerExceptionResolver;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /** * Keafmd * * @ClassName: SysExceptionResolver * @Description: 异常处理器 * @author: 牛哄哄的柯南 * @date: 2021-02-06 10:32 */
    public class SysExceptionResolver implements HandlerExceptionResolver { 
    
        /** * 处理异常的业务逻辑 * @param httpServletRequest * @param httpServletResponse * @param o * @param e * @return */
        @Override
        public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) { 
            //准备获取到异常对象
            SysException se = null;
            if(e instanceof SysException){ 
                se = (SysException)e;
            }else{ 
                se = new SysException("系统正在维护,请联系管理员。。。");
            }
            //创建ModelAndView对象
            ModelAndView mv = new ModelAndView();
            mv.addObject("errorMsg",se.getMessage());
            mv.setViewName("error");
            return mv;
        }
    }

**error.jsp：**

<%--
      Created by IntelliJ IDEA.
      User: Keafmd
      Date: 2021/2/6
      Time: 10:39
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
    
        ${ errorMsg}
    
    </body>
    </html>

### 3、配置异常处理器 ###

**在springmvc.xml里面进行配置：（添加如下配置信息）**

<bean id="sysExceptionResolver" class="com.keafmd.exception.SysExceptionResolver"/>

**springmvc.xml：**

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:mvc="http://www.springframework.org/schema/mvc"
           xmlns:context="http://www.springframework.org/schema/context"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation=" http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd">
    
        
        <context:component-scan base-package="com.keafmd"></context:component-scan>
    
        
        <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/WEB-INF/pages/"></property>
            <property name="suffix" value=".jsp"></property>
        </bean>
    
        
        <mvc:resources location="/css/" mapping="/css/**" />
        <mvc:resources location="/images/" mapping="/images/**" />
        <mvc:resources location="/js/" mapping="/js/**" />
    
        
        <mvc:annotation-driven/>
    
        
        <bean id="sysExceptionResolver" class="com.keafmd.exception.SysExceptionResolver"/>
    
    </beans>

**UserController类（包含异常处理）：**

package com.keafmd.controller;
    
    import com.keafmd.exception.SysException;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    import java.sql.SQLOutput;
    
    /** * Keafmd * * @ClassName: UserController * @Description: * @author: 牛哄哄的柯南 * @date: 2021-02-06 10:14 */
    @Controller
    @RequestMapping("/user")
    public class UserController { 
    
        @RequestMapping("testException")
        public String testException() throws Exception{ 
            System.out.println("testException执行了。。。");
    
            try { 
                //模拟异常
                int a = 10/0;
            } catch (Exception e) { 
                //控制台打印异常信息
                e.printStackTrace();
                //抛出自定义异常信息
                throw new SysException("查询所有用户出现错误了。。");
            }
            return "success";
        }
    
    }

### 异常处理效果演示 ###

**运行效果：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70 4]

> **点击testException后，显示我们自定义的异常信息。**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzg4MzkxNw_size_16_color_FFFFFF_t_70 5]

> **以上就是SpringMVC的异常处理的全部内容。**

**看完如果对你有帮助，感谢点赞支持！  
如果你是电脑端的话，看到右下角的 “一键三连” 了吗，没错点它\[哈哈\]**  
![在这里插入图片描述][20210115230629703.gif_pic_center]

**加油！**

**共同努力！**

**Keafmd**

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[20210115230629703.gif_pic_center]: /images/20221024/58ddee0ade6a4782932858119e17e9aa.png