学习ACEGI

1.建立一个MyEclipse的WebProject，把下列jar文件拷贝到项目的WEB-INF/lib目录:
acegi-security-1.0.3.jar
spring2.0.jar
commons-codec-1.3.jar
2.修改WEB-INF下的web.xml文件,内容如下:

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

	<display-name>acegi Example of liuyxit</display-name>
	
	<!--
		定义应用的上下文参数，用于ContextLoaderListener	  
	-->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>
			classpath:spring/applicationContext.xml
		</param-value>
	</context-param>

	<!--acegi 的filter链代理-->
	<filter>
		<filter-name>Acegi Filter Chain Proxy</filter-name>
		<filter-class>
			org.acegisecurity.util.FilterToBeanProxy
		</filter-class>
		<init-param>
			<param-name>targetClass</param-name>
			<param-value>
				org.acegisecurity.util.FilterChainProxy
			</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>Acegi Filter Chain Proxy</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
	<!--
		装载应用软件的Spring上下文
		要由WebapplicationContextUtils.getWebApplicationnContext(servletContext)得到.
	-->
	<listener>
		<listener-class>
			org.springframework.web.context.ContextLoaderListener
		</listener-class>
	</listener>
</web-app>

其中FilterChainProxy实现了filter接口,它主要是实例化FilterChainProxy，并把所有动作交由FilterChainProxy处理。这样简化了web.xml的配置，并且充分利用了Spring IOC管理Bean的优势。

3.在src目录右键新建一个resource folder，在下面再建立acegi和spring目录
在spring目录中创建applicationContext.xml文件,内容:

<?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:aop="http://www.springframework.org/schema/aop"
	   xmlns:tx="http://www.springframework.org/schema/tx"
	   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"
           default-autowire="byName" default-lazy-init="true">
    
     <!--   ========================  FILTER CHAIN  =======================   --> 
     <bean id="filterChainProxy"   class="org.acegisecurity.util.FilterChainProxy"> 
       <property name="filterInvocationDefinitionSource"> 
          <value> 
            CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
            PATTERN_TYPE_APACHE_ANT
            /**=authenticationProcessingFilter,exceptionTranslationFilter
         </value>
      </property>
    </bean>   
    <!-- ======================== 认证filter ======================= -->
   
    <!-- 表单认证处理filter -->
    <bean id="authenticationProcessingFilter" class="org.acegisecurity.ui.webapp.AuthenticationProcessingFilter">
        <property name="authenticationManager" ref="authenticationManager"/>
        <property name="authenticationFailureUrl" value="/acegilogin.jsp?login_error=1"/>
        <property name="defaultTargetUrl" value="/userinfo.jsp"/>
        <property name="filterProcessesUrl" value="/j_acegi_security_check"/>
    </bean>    
       
   <!-- 认证管理器 -->
   <bean id="authenticationManager" class="org.acegisecurity.providers.ProviderManager">
      <property name="providers"><!-- 可有多个认证提供器,其中一个证通过就可以了 -->
         <list>
            <ref local="daoAuthenticationProvider"/>
         </list>
      </property>
   </bean>   
    <bean id="daoAuthenticationProvider" class="org.acegisecurity.providers.dao.DaoAuthenticationProvider">
        <property name="userDetailsService" ref="inMemoryDaoImpl"/>        
    </bean>    
    <!-- 用户资料-->
     <bean id="inMemoryDaoImpl" class="org.acegisecurity.userdetails.memory.InMemoryDaoImpl">  
        <property name="userMap">  
            <value>  
                liuyxit=123,ROLE_SUPERVISOR
                user1=user1,ROLE_USER
                user2=user2,disabled,ROLE_USER   
            </value>  
        </property>  
    </bean>
    <!-- 异常处理filter -->
    <bean id="exceptionTranslationFilter" class="org.acegisecurity.ui.ExceptionTranslationFilter">
        <property name="authenticationEntryPoint">
            <bean class="org.acegisecurity.ui.webapp.AuthenticationProcessingFilterEntryPoint">
                <property name="loginFormUrl" value="/acegilogin.jsp"/>
                <property name="forceHttps" value="false"/>
            </bean>
        </property>
        <property name="accessDeniedHandler">
            <bean class="org.acegisecurity.ui.AccessDeniedHandlerImpl">
                <property name="errorPage" value="/accessDenied.jsp"/>
            </bean>
        </property>
    </bean>    
</beans> 

[list=A]其中filterChainProxy就是由web.xml声明的filter(FilterToBeanProxy)的targetClass。它主要是装载filterInvocationDefinitionSource指定的filter类(例子中为authenticationProcessingFilter,exceptionTranslationFilter)，并顺序调用它们的doFilter方法，进行安全服务处理。[/list]
[list=B]而authenticationProcessingFilter是处理一个认证表单,登陆用的表单必须提交用户名和密码这两个参数给这个filter.由用户名和密码构造一个UsernamePasswordAuthenticationToken，将传给AuthenticationManager的authenticate方法进行认证处理。该filter默认处理filterProcessesUrl属性指定的URL，认证失败会转到authenticationFailureUrl，认证成功会转到defaultTargetUrl页面。[/list]
[list=C]AuthenticationManager顾名思义认证管理器,它只有一个接口方法authenticate用于返回认证结果，他的实现类由多个AuthenticationProvider进行投票，决定认证是否通过。[/list]
[list=D]daoAuthenticationProvider是检验用户录入的认证数据是否正确(说白了就是用户名和密码是否正确)[/list]
[list=E]inMemoryDaoImpl是给daoAuthenticationProvider提供系统的用户资料。而资料的来源是从配置中装载到内存的。[/list]
[list=F]当认证不通过时,AuthenticationManager的实现类AbstractAuthenticationManager会抛出AuthenticationException类型的异常。这时排在最后的exceptionTranslationFilter会捕获该异常，并转向authenticationEntryPoint。[/list]

4.在WebRoot下创建index.jsp(其实不要也没关系，主要是为了方便)，直接转向用户资料显示页。内容如下:

<%@ page language="java" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
    <META HTTP-EQUIV="Refresh" CONTENT="0;URL=userinfo.jsp">
</head>

<body>
<p>Loading ...</p>
</body>
</html>

5.在WebRoot下创建userinfo.jsp，用于显示当前登陆的用户信息。内容如下

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ page import="org.acegisecurity.context.SecurityContextHolder"%>
<%@ page import="org.acegisecurity.userdetails.*"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<title>My JSP 'pass.jsp' starting page</title>

		<meta http-equiv="pragma" content="no-cache">
		<meta http-equiv="cache-control" content="no-cache">
		<meta http-equiv="expires" content="0">
		<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
		<meta http-equiv="description" content="This is my page">
	</head>

	<body>
		当前用户:
		<%
			Object obj = SecurityContextHolder.getContext().getAuthentication();		
			if (null != obj){
				Object userDetail = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
				String username = "";
				if (userDetail instanceof UserDetails) {
					username = ((UserDetails) userDetail).getUsername();
				} else {
					username = userDetail.toString();
				}
				out.print(username);
				out.print("<br><a href=\"j_acegi_logout\">注销</a>");
			}else{
				out.print("当前没有有效的用户");
				out.print("<br><a href=\"acegilogin.jsp\">登陆</a>");
			}
		%>		
	</body>
</html>

6.在WebRoot下创建acegilogin.jsp

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ page import="org.acegisecurity.ui.AbstractProcessingFilter" %>
<%@ page import="org.acegisecurity.ui.webapp.AuthenticationProcessingFilter" %>
<%@ page import="org.acegisecurity.AuthenticationException" %>
<html>
  <head>
    <title>Login</title>
  </head>
  <body>
    <h1>Login</h1>

	<P>Valid users:
	<P>
	<P>username <b>liuyxit</b>, password <b>123</b> (supervisor)
	<P>username <b>user1</b>, password <b>user1</b> (normal user)
	<p>username <b>user2</b>, password <b>user2</b> (user disabled)
	<p>
    <%
    	String strError = request.getParameter("login_error");    	
    	if (null != strError){ 
     %>
      <font color="red">
        你的登陆失败,请重试。<BR><BR>
         原因: <%= ((AuthenticationException) session.getAttribute(AbstractProcessingFilter.ACEGI_SECURITY_LAST_EXCEPTION_KEY)).getMessage() %>
      </font>
      <%
      	}//end if
      %>

    <form action="j_acegi_security_check" method="POST">
      <table>
        <tr><td>User:</td><td><input type='text' name='j_username' value='<%= session.getAttribute(AuthenticationProcessingFilter.ACEGI_SECURITY_LAST_USERNAME_KEY) %>'></td></tr>
        <tr><td>Password:</td><td><input type='password' name='j_password'></td></tr>
        <tr><td><input type="checkbox" name="_acegi_security_remember_me"></td><td>2周内自动登录</td></tr>

        <tr><td colspan='2'><input name="submit" type="submit"></td></tr>
        <tr><td colspan='2'><input name="reset" type="reset"></td></tr>
      </table>
    </form>

  </body>
</html>

7.OK，发布项目，访问http://localhost:8080/acegiexample
这时index.jsp会自动转向userinfo.jsp,由于还没有用户登录,所以没有资料显示。按登陆链接进入登录页，登录成功后会看到显示用户名的页面（当然可以有更多的用户资料,但这仅仅是example）,不成功时会在登录页提示信息。我们可以用user1和user2登陆，可以分别测试登录成功和失败的流程。

8.可以看到登录页上有自动登陆功能，而userinfo.jsp页有注销功能。但还是不起作用，好，现在我们马上首手加入这两个功能。看acegi可以方便到什么程度。修改applicationContext.xml如下：

I did not understand the login failed part

你说的应该是登陆失败页面吧。就是输错密码，验证没通过的页面

yes, 就是输错密码，验证没通过的页面

女人！！！！！！！！！！！