SpringMVC06Exception 异常处理

　　1.配置web.xml文件

<!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>CharacterEncoding</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>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

　　2.实体类UserInfo

public class UserInfo {
    private String name;
    private Integer age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
}

　　3.1：自定义异常类（用户异常）

public class UserInfoException extends Exception {
    public UserInfoException() {
    }
    public UserInfoException(String message) {
        super(message);
    }
}

　　3.2：自定义异常类（用户名异常）

public class NameException extends UserInfoException {
    public NameException() {
    }
    public NameException(String message) {
        super(message);
    }
}

　　3.3：自定义异常类（年龄异常）

public class AgeException extends UserInfoException {
    public AgeException() {
    }
    public AgeException(String message) {
        super(message);
    }
}

　　4.处理器

import cn.happy.bean.UserInfo;
import cn.happy.exceptions.AgeException;
import cn.happy.exceptions.NameException;
import cn.happy.exceptions.UserInfoException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class FirstController {　　　//异常处理
    @RequestMapping("/first")
    public String doFirst() {
        int result = 5 / 0;
        return "/index.jsp";
    }
    //对象异常处理
    @RequestMapping("/multiException")
    public String doFirst(UserInfo info) throws UserInfoException {
        if (!info.getName().equals("admin")) {
            throw new NameException("用户名错误");
        } else if (info.getAge() > 60) {
            throw new AgeException("年龄错误");
        }
        return "/index.jsp";
    }
}

　　5.映射器

<?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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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">
    <context:component-scan base-package="cn.happy"/>
    <!--注解驱动-->
    <mvc:annotation-driven/>
    <!--异常处理器-->
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <property name="defaultErrorView" value="/error.jsp"/>
        <property name="exceptionAttribute" value="ex"/>
        <property name="exceptionMappings">
            <props>
                <prop key="cn.happy.exceptions.NameException">/NameException.jsp</prop>
                <prop key="cn.happy.exceptions.AgeException">/AgeException.jsp</prop>
            </props>
        </property>
    </bean>
</beans>

　　6.1：视图页面（登录页面）

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="/multiException" method="post">
    用户名：<input name="name"/>
    年龄：<input name="age"/>
    <input type="submit" value="登录"/>
</form>
</body>
</html>

　　6.2：视图页面（异常测试页面）

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>ErrorPage出错了</h2>
${ex.localizedMessage}
</body>
</html>

　　6.3：用户名异常（测试页）

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>用户名错误</h2>
</body>
</html>

　　6.4：年龄异常（测试页）

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>年龄错误</h2>
</body>
</html>