SpringMVC08AnnotationException 注解异常

　　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>
    <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) {
        Age = age;
    }
}

　　3.1：用户异常

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

　　3.2：用户名异常

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

　　3.3：年龄异常

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

　　4.异常解析器（谁继承它，谁就拥有异常解析）

import cn.happy.exceptions.AgeException;
import cn.happy.exceptions.NameException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;
public class BaseController {
    //解析异常
    @ExceptionHandler
    public ModelAndView resolveException(Exception ex) {
        ModelAndView mv = new ModelAndView();
        mv.setViewName("/error.jsp");
        if (ex instanceof NameException) {
            mv.setViewName("/error/NameException.jsp");
        } else if (ex instanceof AgeException) {
            mv.setViewName("/error/AgeException.jsp");
        }
        return mv;
    }
}

　　5.处理器

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.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class FirstController extends BaseController {
    @RequestMapping("/first")
    public String doFirst(String name, int age) throws UserInfoException {
        if (!"admin".equals(name)) {
            throw new NameException("用户名错误");
        } else if (age > 60) {
            throw new AgeException("年龄错误");
        }
        return "/index.jsp";
    }
}

　　6.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"
       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">

    <context:component-scan base-package="cn.happy"/>
</beans>

　　7.1：视图（年龄异常页面）

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

　　7.2.视图（用户名异常页面）

<%@ 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>

　　7.3视图（登录页面）

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

　　7.4：视图（异常页面）

<%@ 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>

　　7.5：视图（登录成功页面）

<html>
<body>
<h2>Hello World!</h2>
</body>
</html>

　　测试页面：测试登录成功

　　测试页面：测试用户名异常

　　测试页面：测试年龄异常