学习Acegi-认证(authentication)

   最近两星期在学习acegi，过程中感谢JavaEye，SpringSide和在网上提供acegi学习心得的网友们。
为了加深自己的认识,准备写下一些DEMO,希望可以给准备学习acegi的同学一些帮助。
      作为安全服务离不开认证和授权这两个主要组成部分。而这篇文章就是针对acegi的认证服务。
                                                                              学习Acegi-认证(authentication)
代码环境基于:
JDK1.5
acegi1.0.3
spring2.0

IDE基于:
Eclipse3.2+MyEclipse5.0.1

面向人员：
熟悉Eclipse＋MyEclipse开发但刚开始了解acegi的人员。如果你是高手请指出文章不足之处。

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
费话说一句(占些字数):这是因为代码运行需要这两个包的支持。

2.修改WEB-INF下的web.xml文件,内容如下:

< web - app version = " 2.4 "  xmlns = " http://java.sun.com/xml/ns/j2ee "
    xmlns:xsi = " http://www.w3.org/2001/XMLSchema-instance "
    xsi:schemaLocation = " http://java.sun.com/xml/ns/j2ee 
    http: // java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

     < display - name > acegi Example of liuyxit
    
    
     < context - param >
         < param - name > contextConfigLocation
         < param - value >
            classpath:spring / applicationContext.xml
        
    

    
     < filter >
         < filter - name > Acegi Filter Chain Proxy
         < filter - class >
            org.acegisecurity.util.FilterToBeanProxy
        
         < init - param >
             < param - name > targetClass
             < param - value >
                org.acegisecurity.util.FilterChainProxy
            
        
    

     < filter - mapping >
         < filter - name > Acegi Filter Chain Proxy
         < url - pattern > /*
    

    
    
        
            org.springframework.web.context.ContextLoaderListener
        
    

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:

< 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 " >
    
    
     < bean id = " filterChainProxy "   class = " org.acegisecurity.util.FilterChainProxy " >
       < property name = " filterInvocationDefinitionSource " >
          < value >
            CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
            PATTERN_TYPE_APACHE_ANT
             /** =authenticationProcessingFilter,exceptionTranslationFilter
         
      
       
    
   
    
    
        
        
        
        
        
       
   
   
      
         
            
            
         
      
      
    
                
        
    
       
          
              
                liuyxit=123,ROLE_SUPERVISOR
                user1=user1,ROLE_USER
                user2=user2,disabled,ROLE_USER   
              
          
    
    
    
        
            
                
                
            
        
        
            
                
            
        
        

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。
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。

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。

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)

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。

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。

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 " %>

< html >
< head >
     
     < META HTTP - EQUIV = " Refresh "  CONTENT = " 0;URL=userinfo.jsp " >


< body >
< p > Loading 

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.* " %>
<%
    String path  =  request.getContextPath();
    String basePath  =  request.getScheme()  +   " :// "
             +  request.getServerName()  +   " : "   +  request.getServerPort()
             +  path  +   " / " ;
%>


< html >
     < head >
         < base href = " <%=basePath%> " >

         < title > My JSP  ‘ pass.jsp ‘  starting page

         < 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 " >
        

    

     < 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( "
注销 " );
            } else {
                out.print( " 当前没有有效的用户 " );
                out.print( "
登陆 " );
            }
         %>
        
        
    

 

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
  
   < body >
     < h1 > Login

     < P > Valid users:
     < P >
     < P > username  < b > liuyxit , password  < b > 123  (supervisor)
     < P > username  < b > user1 , password  < b > user1  (normal user)
     < p > username  < b > user2 , password  < b > user2  (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()  %>
      
       <%
          } // end if
       %>

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

         < tr >< td colspan = ‘ 2 ‘ >< input name = " submit "  type = " submit " >
         < tr >< td colspan = ‘ 2 ‘ >< input name = " reset "  type = " reset " >
      

    

  

6,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。

7.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。在applicationContext.xml中加入如下红色部分：

< 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 " >
    
    
     < bean id = " filterChainProxy "   class = " org.acegisecurity.util.FilterChainProxy " >
       < property name = " filterInvocationDefinitionSource " >
          < value >
            CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
            PATTERN_TYPE_APACHE_ANT
             /** =authenticationProcessingFilter,logoutFilter,rememberMeProcessingFilter,exceptionTranslationFilter
         
      
       
    
   
    
    
        
        
        
        
    
    
    
              class="org.acegisecurity.ui.rememberme.RememberMeProcessingFilter">
                          ref="authenticationManager"/>
        
        
              class="org.acegisecurity.ui.rememberme.TokenBasedRememberMeServices">
        
        
      
              class="org.acegisecurity.providers.rememberme.RememberMeAuthenticationProvider">
        
       
    
    
    
       
      
         
              
              
         
      
   
    
   
   
      
         
            
            
         
      
      
    
                
        
    
       
          
              
                liuyxit=123,ROLE_SUPERVISOR
                user1=user1,ROLE_USER
                user2=user2,disabled,ROLE_USER   
              
          
    
    
    
        
            
                
                
            
        
        
            
                
            
        
        

另要注意：Acegi默认的自动登陆设定参数名为_acegi_security_remember_me，注销链接为/j_acegi_logout。

马上重启Tomcat测试看看^_^。

8.通常用户资料会放在数据库中，而不会放在配置文件，接着下面我们来再行修改一下。
首先创建要用到的用户表和权限表，并插入初始化数据：

CREATE TABLE USERS(
USERNAME VARCHAR( 50 ) NOT NULL PRIMARY KEY,
PASSWORD VARCHAR( 50 ) NOT NULL,
ENABLED BIT NOT NULL)

INSERT INTO USERS(username,password,enabled) values( ‘ liuyxit ‘ , ‘ 123 ‘ , ‘ 1 ‘ )
INSERT INTO USERS(username,password,enabled) values( ‘ user1 ‘ , ‘ user1 ‘ , ‘ 1 ‘ )
INSERT INTO USERS(username,password,enabled) values( ‘ user2 ‘ , ‘ user2 ‘ , ‘ 0 ‘ )

CREATE TABLE AUTHORITIES(
USERNAME VARCHAR( 50 ) NOT NULL,
AUTHORITY VARCHAR( 50 ) NOT NULL,
CONSTRAINT FK_AUTHORITIES_USERS FOREIGN KEY(USERNAME) REFERENCES USERS(USERNAME)
);

INSERT INTO AUTHORITIES(USERNAME,AUTHORITY) values( ‘ liuyxit ‘ , ‘ ROLE_SUPERVISOR ‘ )
INSERT INTO AUTHORITIES(USERNAME,AUTHORITY) values( ‘ user1 ‘ , ‘ ROLE_USER ‘ )
INSERT INTO AUTHORITIES(USERNAME,AUTHORITY) values( ‘ user2 ‘ , ‘ ROLE_USER ‘ )

这里我用的是acegi默认的数据结构，可以改只要你指定JdbcDaoImpl的authoritiesByUsernameQuery和usersByUsernameQuery属性就可以了。另AUTHORITIES表也要一同加入，原因acegi获得userDetail时，也会读取这个表的内容，否则会抛“nested exception is java.sql.SQLException: 对象名 ‘authorities‘ 无效”这个异常。

修改applicationContext.xml，变成如下：

< 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" >
    
     < bean  id ="dataSource"  class ="org.springframework.jdbc.datasource.DriverManagerDataSource" >
         < property  name ="driverClassName" >
            
             < value > net.sourceforge.jtds.jdbc.Driver             
        
         < property  name ="url" >
            
             < value > jdbc:jtds:sqlserver://localhost:1433/javauser
        
         < property  name ="username" >
             < value > sa
        
         < property  name ="password" >
             < value > javauser
        
    
  
    
     < bean  id ="filterChainProxy"  class ="org.acegisecurity.util.FilterChainProxy" >
       < property  name ="filterInvocationDefinitionSource" >
          < value >
            CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
            PATTERN_TYPE_APACHE_ANT
            /**=authenticationProcessingFilter,logoutFilter,rememberMeProcessingFilter,exceptionTranslationFilter
         
      
        
    
   
    
     < 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  id ="rememberMeProcessingFilter"
          class ="org.acegisecurity.ui.rememberme.RememberMeProcessingFilter" >
         < property  name ="authenticationManager"
                  ref ="authenticationManager" />
         < property  name ="rememberMeServices"  ref ="rememberMeServices" />
         
     < bean  id ="rememberMeServices"
          class ="org.acegisecurity.ui.rememberme.TokenBasedRememberMeServices" >
         < property  name ="userDetailsService"  ref ="jdbcDaoImpl" />
         < property  name ="key"  value ="javargb" />
       
     < bean  id ="rememberMeAuthenticationProvider"
          class ="org.acegisecurity.providers.rememberme.RememberMeAuthenticationProvider" >
         < property  name ="key"  value ="javargb" />
        
    
    
     < bean  id ="logoutFilter"  class ="org.acegisecurity.ui.logout.LogoutFilter" >
       < constructor-arg  value ="/acegilogin.jsp" />  
       < constructor-arg >
          < list >
               < ref  bean ="rememberMeServices" />
               < bean  class ="org.acegisecurity.ui.logout.SecurityContextLogoutHandler" />
         
      
   
    
   
    < bean  id ="authenticationManager"  class ="org.acegisecurity.providers.ProviderManager" >
       < property  name ="providers" >
          < list >
             < ref  local ="daoAuthenticationProvider" />
             < ref  local ="rememberMeAuthenticationProvider" />
         
      
       
     < bean  id ="daoAuthenticationProvider"  class ="org.acegisecurity.providers.dao.DaoAuthenticationProvider" >
         < property  name ="userDetailsService"  ref ="jdbcDaoImpl" />         
         
    
     < bean  id ="jdbcDaoImpl"  class ="org.acegisecurity.userdetails.jdbc.JdbcDaoImpl" >
         < property  name ="dataSource" >< ref  bean ="dataSource" />
    
    
    
     < 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" />
            
        
         < property  name ="accessDeniedHandler" >
             < bean  class ="org.acegisecurity.ui.AccessDeniedHandlerImpl" >
                 < property  name ="errorPage"  value ="/accessDenied.jsp" />
            
        
         

这时userDetailsService是通过实现类jdbcDaoImpl从数据库获得用户资料来作认证比较。

OK，大功告成。

后记：很少写技术文章，除了要坚持之外，文笔和思路都很重要。感觉自己的写作水平太差了，希望大家指出不合理的地方。有时间我会再写后篇《学习Acegi-授权(authorization)》,感谢大家把拙文看完，TKS!