1.1 Spring Security简介
Spring Security是一个能够为基于Spring的企业应用系统提供声明式的安全访问控制解决方案的安全框架。它提供了一组可以在Spring应用上下文中配置的Bean，充分利用了Spring IoC，DI（控制反转Inversion of Control ,DI:Dependency Injection 依赖注入）和AOP（面向切面编程）功能，为应用系统提供声明式的安全访问控制功能，减少了为企业系统安全控制编写大量重复代码的工作。
1.2 Spring Security Demo
（1）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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.qiluo</groupId>
<artifactId>spring-security</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<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>1.8</source>
<target>1.8</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>
（2）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">
<display-name>spring-security</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<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"> <!-- 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> <!-- 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>
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。
配置说明：
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')" />
（4）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>