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:
cded
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

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