初识Spring Security

       xmlns:security="http://www.springframework.org/schema/security"
       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">

    <!--http元素用于定义Web相关权限控制。-->
    <!--intercept-url定义了一个权限控制的规则。
    pattern属性表示我们将对哪些url进行权限控制，其也可以是一个正则表达式，如上的写法表示我们将对所有的URL进行权限控制；
    access属性表示在请求对应的URL时需要什么权限，默认配置时它应该是一个以逗号分隔的角色列表，请求的用户只需拥有其中的一个角色就能成功访问对应的URL。
    这里的“ROLE_USER”表示请求的用户应当具有ROLE_USER角色。“ROLE_”前缀是一个提示Spring使用基于角色的检查的标记。-->
    <!--注：auto-config="true"时，SpringSecurity发现没有登录回自动创建登陆页面-->
    <security:http auto-config="true">
        <security:intercept-url pattern="/**" access="ROLE_USER"/>
    </security:http>

    <!--使用AuthenticationManager 进行认证相关配置-->
    <!--authentication-manager元素指定了一个AuthenticationManager，其需要一个AuthenticationProvider（对应authentication-provider元素）来进行真正的认证-->
    <security:authentication-manager>
        <security:authentication-provider>
            <security:user-service>
                <security:user name="user" password="user" authorities="ROLE_USER"/>
                <security:user name="admin" password="admin" authorities="ROLE_USER, ROLE_ADMIN"/>
            </security:user-service>
        </security:authentication-provider>
    </security:authentication-manager>
</beans>

 <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml,/WEB-INF/spring-security.xml</param-value>
    </context-param>

<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>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <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>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml,/WEB-INF/spring-security.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
</web-app>