创建工程spring-security-demo ,pom.xml内容
<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>cn.itcast.demo</groupId>
<artifactId>spring-security-demo</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<properties>
<spring.version>4.2.4.RELEASE</spring.version>
</properties>
<dependencies>
<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-webmvc</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>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-web</artifactId>
<version>4.1.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-config</artifactId>
<version>4.1.0.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<!-- java编译插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<configuration>
<!-- 指定端口 -->
<port>9090</port>
<!-- 请求路径 -->
<path>/</path>
</configuration>
</plugin>
</plugins>
</build>
</project>
创建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_2_5.xsd"
version="2.5">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-security.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<filter>
<filter-name>springSecurityFilterChain</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
（3）创建index.html
（4）创建spring 配置文件spring-security.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security"
xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd">
<!-- 页面拦截规则 -->
<http use-expressions="false">
<!-- /**包括子目录 /*只包含根目录，不包含子目录 -->
<intercept-url pattern="/**" access="ROLE_USER" />
<form-login/>
</http>
<!-- 认证管理器 -->
<authentication-manager>
<authentication-provider>
<user-service>
<user name="admin" password="123456" authorities="ROLE_USER"/>
</user-service>
</authentication-provider>
</authentication-manager>
</beans:beans>
intercept-url 表示拦截页面
/* 表示的是该目录下的资源，只包括本级目录不包括下级目录
/** 表示的是该目录以及该目录下所有级别子目录的资源
form-login 为开启表单登陆
use-expressions 为是否使用使用 Spring 表达式语言（ SpEL ），默认为true ,如果开启，则拦截的配置应该写成以下形式
<intercept-url pattern="/**" access="hasRole('ROLE_USER')" />用户自定义登录页
（1）构建登陆页：
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登陆</title>
</head>
<body>
<form action='/login' method='POST'>
<table>
<tr>
<td>用户名:</td>
<td><input type='text' name='username' value=''></td>
</tr>
<tr>
<td>密码:</td>
<td><input type='password' name='password' /></td>
</tr>
<tr>
<td colspan='2'><input name="submit" type="submit"
value="登陆" /></td>
</tr>
</table>
</form>
</body>
</html>
（2）构建登陆失败页 login_error.html
（3）修改 spring 配置文件spring-security.xml
<!-- 以下页面不被拦截 -->
<http pattern="/login.html" security="none"></http>
<http pattern="/login_error.html" security="none"></http>
<!-- 页面拦截规则 -->
<http use-expressions="false">
<intercept-url pattern="/*" access="ROLE_USER" />
<form-login login-page="/login.html" default-target-url="/index.html" authentication-failure-url="/login_error.html"/>
<csrf disabled="true"/>
</http>
security="none" 设置此资源不被拦截.
如果你没有设置登录页security="none" ，将会出现以下错误
因为登录页会被反复重定向。
login-page：指定登录页面。
authentication-failure-url：指定了身份验证失败时跳转到的页面。
default-target-url：指定了成功进行身份验证和授权后默认呈现给用户的页面。
csrf disabled="true" 关闭csrf ,如果不加会出现错误
CSRF（Cross-site request forgery）跨站请求伪造，也被称为“One Click Attack”或者Session Riding，
通常缩写为CSRF或者XSRF，是一种对网站的恶意利用。
