SSM-SpringMVC-25：SpringMVC异常顶级之自定义异常解析器

------------吾亦无他,唯手熟尔，谦卑若愚，好学若饥-------------

上篇博客相信大家也看到了，自定义异常，用了SimpleMappingExceptionResolver这个解析器，本次要讲的是自定义异常解析器：

自己定义的异常解析器，实现了HandlerExceptionResolver,一会再在xml中配置一道，我把需要改或者新建的三处放在前面，下面的与上篇博客的一样（不过我也放上来），看着来把，活学活用

案例

　　1，自定义异常解析器MyHandlerExceptionResolver：

package cn.dawn.day17selfexceptionresolver.resolver;

import cn.dawn.day17selfexceptionresolver.userexception.UserageException;
import cn.dawn.day17selfexceptionresolver.userexception.UsernameException;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * Created by Dawn on 2018/3/30.
 */
public class MyHandlerExceptionResolver implements HandlerExceptionResolver {
    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        ModelAndView modelAndView=new ModelAndView();
        /*返回的异常对象*/
        modelAndView.addObject("ex",ex);
        /*判断去那个页面*/
        if(ex instanceof UsernameException){
            modelAndView.setViewName("name");
        }
        if(ex instanceof UserageException){
            modelAndView.setViewName("age");
        }

        return modelAndView;
    }
}

　　2.自己的xml大配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       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">

    <!--包扫描器-->
    <context:component-scan base-package="cn.dawn.day17selfexceptionresolver"></context:component-scan>
    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/day17/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <!--自己的异常解析器-->
    <bean class="cn.dawn.day17selfexceptionresolver.resolver.MyHandlerExceptionResolver"></bean>

</beans>

　　3.讲web.xml中央调度器的上下文配置位置改为你现在这个配置xml

　　下面的上篇博客就有，不过我也再放一份，ok

　　4.UserageException自定义异常

package cn.dawn.day17selfexceptionresolver.userexception;

/**
 * Created by Dawn on 2018/3/30.
 */
public class UserageException extends Exception {
    public UserageException() {
        super();
    }

    public UserageException(String message) {
        super(message);
    }
}

　　5.UsernameException自定义异常

package cn.dawn.day17selfexceptionresolver.userexception;

/**
 * Created by Dawn on 2018/3/30.
 */
public class UsernameException extends Exception {
    public UsernameException() {
        super();
    }

    public UsernameException(String message) {
        super(message);
    }
}

　　6.自定义的处理器和处理方法

package cn.dawn.day17selfexceptionresolver;

import cn.dawn.day17selfexceptionresolver.userexception.UserageException;
import cn.dawn.day17selfexceptionresolver.userexception.UsernameException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * Created by Dawn on 2018/3/28.
 */
@Controller
public class ZDYExceptionController {
    @RequestMapping("/zidingyiException")
    public String zidingyiException(String username,Integer userage) throws Exception {
        if(!username.equals("admin")){
            throw new UsernameException("登陆名不正确");
        }
        if(userage<){
            throw new UserageException("未成年，走开");
        }
        return "success";
    }
}

　　7.jsp页面

　　　　7.1login.jsp

<%@ page  pageEncoding="UTF-8" contentType="text/html;charset=UTF-8" language="java" isELIgnored="false"  %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>登录</h2>
<form action="${pageContext.request.contextPath}/zidingyiException" method="post">

    用户名:<input name="username">
    年龄:<input name="userage">

    <input type="submit" value="登录"/>
</form>
</body>
</html>

　　　　7.2success.jsp

<%@ page language="java" pageEncoding="utf-8" isELIgnored="false" %>
<html>
<body>
<%--<img src="data:image/1.jpg">--%>
<h2>Success!</h2>
</body>
</html>

　　　　7.3error.jsp

<%@ page  pageEncoding="UTF-8" contentType="text/html;charset=UTF-8" language="java" isELIgnored="false"  %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>ERROR</h2>
<p>${ex.message}</p>
服务器被猴子砍了，攻城狮在抢修中，还杀了个程序猿祭天
</body>
</html>

　　　　7.4age.jsp

<%@ page  pageEncoding="UTF-8" contentType="text/html;charset=UTF-8" language="java" isELIgnored="false"  %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>年龄错误ERROR</h2>
<p>${ex.message}</p>
服务器被猴子砍了，攻城狮在抢修中，还杀了个程序猿祭天
</body>
</html>

　　　　7.5name.jsp

<%@ page  pageEncoding="UTF-8" contentType="text/html;charset=UTF-8" language="java" isELIgnored="false"  %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>名字错误ERROR</h2>
<p>${ex.message}</p>
服务器被猴子砍了，攻城狮在抢修中，还杀了个程序猿祭天
</body>
</html>

　　8.启动tomcat，访问login.jsp