SpringMVCDemo-登录小例子

项目全部目录：

1、使用Eclipse或者MyEclipse创建一个maven项目SpringMVCDemo，打开pom.xml配置Spring核心包

pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>SpringMVCDemo</groupId>
  <artifactId>SpringMVCDemo</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringMVCDemo Maven Webapp</name>
  <url>http://maven.apache.org</url>
   <properties>  
    <!-- spring版本号 -->  
    <spring.version>4.0.2.RELEASE</spring.version>  
    <!-- log4j日志文件管理包版本 -->  
    <slf4j.version>1.7.7</slf4j.version>  
    <log4j.version>1.2.17</log4j.version>  
  </properties> 
  
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

	<!-- spring核心包 -->  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-core</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-web</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-oxm</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-tx</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-jdbc</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-webmvc</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-aop</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-context-support</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-test</artifactId>  
        <version>${spring.version}</version>  
    </dependency> 
    
    <!-- 日志文件管理包 -->  
    <!-- log start -->  
    <dependency>  
        <groupId>log4j</groupId>  
        <artifactId>log4j</artifactId>  
        <version>${log4j.version}</version>  
    </dependency>  
      
    <!-- 格式化对象，方便输出日志 -->  
    <dependency>  
        <groupId>com.alibaba</groupId>  
        <artifactId>fastjson</artifactId>  
        <version>1.1.41</version>  
    </dependency>  

    <dependency>  
        <groupId>org.slf4j</groupId>  
        <artifactId>slf4j-api</artifactId>  
        <version>${slf4j.version}</version>  
    </dependency>  

    <dependency>  
        <groupId>org.slf4j</groupId>  
        <artifactId>slf4j-log4j12</artifactId>  
        <version>${slf4j.version}</version>  
    </dependency>    
    <!-- log end -->  

  </dependencies>
  <build>
    <finalName>SpringMVCDemo</finalName>
  </build>
</project>

2、配置web.xml：

<?xml version="1.0" encoding="UTF-8"?>  

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns="http://java.sun.com/xml/ns/javaee"  
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"  
    version="3.0">  
    <display-name>Archetype Created Web Application</display-name>  
  
  <!-- 设置静态文件访问  -->
  <servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.jpg</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.js</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.css</url-pattern>
  </servlet-mapping>
  
  <!-- 编码过滤器 -->  
  <filter>  
      <filter-name>encodingFilter</filter-name>  
      <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  
      <async-supported>true</async-supported>  
      <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>  
    
  <!-- 配置log4j.xml监听器 -->  
  <listener>  
      <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>  
  </listener>  
  <context-param>  
      <param-name>log4jConfigLocation</param-name>  
      <param-value>classpath:log4j.properties</param-value>  
  </context-param> 
  
  <!-- 定义Spring MVC的前端控制器 -->
  <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>  
        <async-supported>true</async-supported>  
   </servlet> 
  
  <servlet-mapping>
  	<servlet-name>SpringMVC</servlet-name>
  	<url-pattern>/</url-pattern>
  </servlet-mapping>
  
</web-app>

3、创建在webapp目录下login.jsp、在WEB-INF目录下创建jsp文件夹，并在jspwen文件夹内创建wellcome.jsp

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index.jps：（解释，不管是否已经登录，重新访问页面都是先跳转到登录界面）

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
	String path = request.getContextPath();
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
		response.sendRedirect(path + "/login.jsp");
%>
</body>
</html>

login.jsp：（使用到了bootstrap，请自行下载bootstrap.min.css，放在css目录，或者如下放在webapp中创建的bootstrap/css目录下，引入即可）

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
	String path = request.getContextPath();
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Login</title>
<link href="bootstrap/css/bootstrap.min.css" rel="stylesheet" media="screen">
</head>
<body>
	<div style="height: 100px"></div>

	<div style="width: 300px; margin: auto;">
		<h2>Welcome to you !</h2>
		<br>
		<form action="login" method="post">
			<fieldset>
				<legend>Login</legend>
				<input type="text" id="username" name="username">
				<input type="password" id="password" name="password"><br>
				<button type="submit" class="btn">Login</button>
				<button type="reset" class="btn">Reset</button>
			</fieldset>
		</form>
	</div>
</body>
</html>

wellcome.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
	String path = request.getContextPath();
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>欢迎${sessionScope.loginUser}登录系统</h1>
</body>
</html>

4、在src/main/resources目录创建log4j.properties和spring-mvc.xml

log4j.properties：

#定义LOG输出级别  
log4j.rootLogger=INFO,Console,File  
#定义日志输出目的地为控制台  
log4j.appender.Console=org.apache.log4j.ConsoleAppender  
log4j.appender.Console.Target=System.out  
#可以灵活地指定日志输出格式，下面一行是指定具体的格式  
log4j.appender.Console.layout = org.apache.log4j.PatternLayout  
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n  
  
#文件大小到达指定尺寸的时候产生一个新的文件  
log4j.appender.File = org.apache.log4j.RollingFileAppender  
#指定输出目录  
log4j.appender.File.File = logs/ssm.log  
#定义文件最大大小  
log4j.appender.File.MaxFileSize = 10MB  
# 输出所以日志，如果换成DEBUG表示输出DEBUG以上级别日志  
log4j.appender.File.Threshold = ALL  
log4j.appender.File.layout = org.apache.log4j.PatternLayout  
log4j.appender.File.layout.ConversionPattern =[%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m%n  

spring-mvc.xml：

<?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:p="http://www.springframework.org/schema/p"  
    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-3.1.xsd    
                        http://www.springframework.org/schema/context    
                        http://www.springframework.org/schema/context/spring-context-3.1.xsd    
                        http://www.springframework.org/schema/mvc    
                        http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">  
    
    <!-- 自动扫描包，使SpringMVC认为包下用了@Controller注解的类是控制器 -->  
	<context:component-scan base-package="com.cn.controller" />
	
	<!--避免IE执行AJAX时，返回JSON出现下载文件 -->  
    <bean id="mappingJacksonHttpMessageConverter"  
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">  
        <property name="supportedMediaTypes">  
            <list>  
                <value>text/html;charset=UTF-8</value>  
            </list>  
        </property>  
    </bean>  
	
	 <!-- 启动SpringMVC的注解功能，完成请求和注解POJO的映射 -->  
    <bean  
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
        <property name="messageConverters">  
            <list>  
                <ref bean="mappingJacksonHttpMessageConverter" /> <!-- JSON转换器 -->  
            </list>  
        </property>  
    </bean>  
	
	<!-- 定义跳转的文件的前后缀 ，视图模式配置-->  
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <!-- 这里的配置我的理解是自动给后面action的方法return的字符串加上前缀和后缀，变成一个 可用的url地址 -->  
        <property name="prefix" value="/WEB-INF/jsp/" />  
        <property name="suffix" value=".jsp" />  
    </bean> 
</beans>

5、在src/main/java目录下创建包com.cn.controller、com.cn.entity，并在com.cn.entity包下创建User.java，在com.cn.controller包下创建LoginController.java

User.java：

package com.cn.entity;

public class User {

	private String username; //用户名
	private String password; //密码
	
	public User(){
		
	}

	public User(String username, String password) {
		super();
		this.username = username;
		this.password = password;
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	@Override
	public String toString() {
		return "User [username=" + username + ", password=" + password + "]";
	}
}

LoginController.java：

package com.cn.controller;

import javax.servlet.http.HttpSession;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.cn.entity.User;

/*
 * LoginController是一个基于注解的控制器，
 * 可以同时处理多个请求动作，并且无须实现任何借口。
 * org.springframework.stereotype.Controller注解用于指示该类是一个控制器
 * */
@Controller
public class LoginController {
	
	/**  
     * org.springframework.web.bind.annotation.RequestMapping注解  
     * 用来映射请求的URL和请求的方法等。本例用来映射"login"  
     * login只是一个普通方法。该方法返回一个包含视图路径或视图路径和模型的ModelAndView对象。  
     * */
	@RequestMapping(value="/login", method=RequestMethod.POST)
	public ModelAndView login(@ModelAttribute User user, HttpSession session) {

               String username = user.getUsername(); //获取form表单的username字段
		String password = user.getPassword(); //获取password
		System.out.println(username + " " + password); //在控制台输出

               ModelAndView mv = new ModelAndView(); //创建ModelAndView对象
		if("admin".equals(username) && "123456".equals(password)){
			//登录成功
			session.setAttribute("loginUser", username);
			mv.setViewName("wellcome"); //设置视图名称
		}else{
			//登录失败
			mv.setViewName("login");
		}
		return mv;
	}
}

6、将项目添加到Tomcat，启动Tomcat，访问http://localhost:8080/SpringMVCDemo