配置异常解析器是为了给用户更好的体验，以至于不会出现一堆报错显示在页面上！
pom依赖，web.xml配置，springmvc配置，index页面见下
pom依赖
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<spring.version>5.2.6.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.1</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
</dependencies>
web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
springmvc.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 开启自动扫描 -->
<context:component-scan base-package="com.lp"/>
<!-- 注册SpringMVC注解开发驱动 -->
<mvc:annotation-driven/>
<!-- 视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/WEB-INF/pages/"></property>
<!-- 后缀 -->
<property name="suffix" value=".jsp"></property>
</bean>
<!-- 前端控制器，哪些静态资源不拦截-->
<mvc:resources mapping="/js/**" location="/js/"/>
<mvc:resources mapping="/css/**" location="/css/"/>
<mvc:resources mapping="/img/**" location="/img/"/>
<bean id="sysExceptionResolver" class="com.lp.exception.SysExceptionResolver"/>
</beans>
首页
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<body>
<h2>Hello World!</h2>
<h3>
<a href="/user/test">测试</a>
</h3>
</body>
</html>
首先，异常解析器我们需要定义一个异常类来继承Exception类
package com.lp.exception;
/**
* @Date 2020/6/5 15:19
* @Author luopeng
*/
public class SysException extends Exception {
private String msg;
public SysException(String msg) {
this.msg = msg;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
}
我们在控制层需要来捕捉异常
package com.lp.controller;
import com.lp.exception.SysException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
/**
* @Date 2020/6/5 15:11
* @Author luopeng
*/
@Controller
@RequestMapping("/user")
public class UserController {
@RequestMapping("/test")
public String test() throws Exception {
try {
System.out.println("异常测试！");
int i = 10 / 0;
return "success";
} catch (Exception e) {
e.printStackTrace();
throw new SysException("出现异常");
}
}
}
前部分工作做好了，我们需要配置一个异常解析器的类来实现HandlerExceptionResolver接口
package com.lp.exception;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @Date 2020/6/5 15:23
* @Author luopeng
*/
public class SysExceptionResolver implements HandlerExceptionResolver {
@Override
public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
//获取异常对象
SysException sysException = null;
//判断传过来的Exception是不是SysException类型
if (e instanceof SysException) {
sysException = (SysException) e;
} else {
sysException = new SysException("系统正在维护！");
}
ModelAndView modelAndView = new ModelAndView();
modelAndView.addObject("error", sysException.getMsg());
modelAndView.setViewName("error");
return modelAndView;
}
}
通过获得到的信息，将出现的异常发送给页面，用更好的形式，而不是一对异常堆栈信息
<%--
Created by IntelliJ IDEA.
User: LuoPeng
Date: 2020/6/5
Time: 15:46
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
<title>错误页面</title>
</head>
<body>
<h1>错了</h1>
<h2>${error}</h2>
</body>
</html>
此时当你运行程序，发生错误会跳转到友好的错误页面，显然我的页面就几个字，一点儿也不友好，但是我技术有限，写不来友好的前端页面！嘻嘻！