这几天学习了一下Spring Security3.1，从官网下载了Spring Security3.1版本进行练习，经过多次尝试才摸清了其中的一些原理。本人不才，希望能帮助大家。还有，这次我第二次写博客啊，文体不是很行。希望 能让观看者不产生疲惫的感觉，我已经心满意足了。
一、数据库结构
先来看一下数据库结构，采用的是基于角色-资源-用户的权限管理设计。(MySql数据库)
为了节省篇章，只对比较重要的字段进行注释。
1.用户表Users
CREATE TABLE `users` (
-- 账号是否有限 1. 是 0.否
`enable` int(11) default NULL,
`password` varchar(255) default NULL,
`account` varchar(255) default NULL,
`id` int(11) NOT NULL auto_increment,
PRIMARY KEY (`id`)
)
2.角色表Roles
CREATE TABLE `roles` (
`enable` int(11) default NULL,
`name` varchar(255) default NULL,
`id` int(11) NOT NULL auto_increment,
PRIMARY KEY (`id`)
)
3 用户_角色表users_roles
CREATE TABLE `users_roles` (
--用户表的外键
`uid` int(11) default NULL,
--角色表的外键
`rid` int(11) default NULL,
`urId` int(11) NOT NULL auto_increment,
PRIMARY KEY (`urId`),
KEY `rid` (`rid`),
KEY `uid` (`uid`),
CONSTRAINT `users_roles_ibfk_1` FOREIGN KEY (`rid`) REFERENCES `roles` (`id`),
CONSTRAINT `users_roles_ibfk_2` FOREIGN KEY (`uid`) REFERENCES `users` (`id`)
)
4.资源表resources
CREATE TABLE `resources` (
`memo` varchar(255) default NULL,
-- 权限所对应的url地址
`url` varchar(255) default NULL,
--优先权
`priority` int(11) default NULL,
--类型
`type` int(11) default NULL,
--权限所对应的编码，例201代表发表文章
`name` varchar(255) default NULL,
`id` int(11) NOT NULL auto_increment,
PRIMARY KEY (`id`)
)
5.角色_资源表roles_resources
CREATE TABLE `roles_resources` (
`rsid` int(11) default NULL,
`rid` int(11) default NULL,
`rrId` int(11) NOT NULL auto_increment,
PRIMARY KEY (`rrId`),
KEY `rid` (`rid`),
KEY `roles_resources_ibfk_2` (`rsid`),
CONSTRAINT `roles_resources_ibfk_2` FOREIGN KEY (`rsid`) REFERENCES `resources` (`id`),
CONSTRAINT `roles_resources_ibfk_1` FOREIGN KEY (`rid`) REFERENCES `roles` (`id`)
)
二、系统配置
所需要的jar包，请自行到官网下 载，我用的是Spring Security3.1.0.RC1版的。把dist下的除了源码件包导入就行了。还有那些零零碎的 数据库驱动啊，log4j.jar等等，我相信在用Spring Security之前，大家已经会的了。
1） web.xml
<!-- Spring -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml,classpath:applicationContext-security.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 权限 -->
<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>
这里主要是配置了让容器启动的时候加载application-security.xml和Spring Security的权限过滤器代理,让其过滤所有的客服请求。 2）application-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-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.1.xsd">
<global-method-security pre-post-annotations="enabled" />
<!-- 该路径下的资源不用过滤 -->
<http pattern="/js/**" security="none"/>
<http use-expressions="true" auto-config="true">
<form-login />
<logout/>
<!-- 实现免登陆验证 -->
<remember-me />
<session-management invalid-session-url="/timeout.jsp">
<concurrency-control max-sessions="10" error-if-maximum-exceeded="true" />
</session-management>
<custom-filter ref="myFilter" before="FILTER_SECURITY_INTERCEPTOR"/>
</http>
<!-- 配置过滤器 -->
<beans:bean id="myFilter" class="com.huaxin.security.MySecurityFilter">
<!-- 用户拥有的权限 -->
<beans:property name="authenticationManager" ref="myAuthenticationManager" />
<!-- 用户是否拥有所请求资源的权限 -->
<beans:property name="accessDecisionManager" ref="myAccessDecisionManager" />
<!-- 资源与权限对应关系 -->
<beans:property name="securityMetadataSource" ref="mySecurityMetadataSource" />
</beans:bean>
<!-- 实现了UserDetailsService的Bean -->
<authentication-manager alias="myAuthenticationManager">
<authentication-provider user-service-ref="myUserDetailServiceImpl" />
</authentication-manager>
<beans:bean id="myAccessDecisionManager" class="com.huaxin.security.MyAccessDecisionManager"></beans:bean>
<beans:bean id="mySecurityMetadataSource" class="com.huaxin.security.MySecurityMetadataSource">
<beans:constructor-arg name="resourcesDao" ref="resourcesDao"></beans:constructor-arg>
</beans:bean>
<beans:bean id="myUserDetailServiceImpl" class="com.huaxin.security.MyUserDetailServiceImpl">
<beans:property name="usersDao" ref="usersDao"></beans:property>
</beans:bean>
</beans:beans>
我们在第二个http标签下配置一个我们自定义的继承了org.springframework.security.access.intercept.AbstractSecurityInterceptor的Filter，并注入其
必须的3个组件authenticationManager、accessDecisionManager和securityMetadataSource。其作用上面已经注释了。
<custom-filter ref="myFilter" before="FILTER_SECURITY_INTERCEPTOR"/> 这里的FILTER_SECURITY_INTERCEPTOR是Spring Security默认的Filter，
我们自定义的Filter必须在它之前，过滤客服请求。接下来看下我们最主要的myFilter吧。
3）myFilter
(1) MySecurityFilter.java 过滤用户请求
public class MySecurityFilter extends AbstractSecurityInterceptor implements Filter {
//与applicationContext-security.xml里的myFilter的属性securityMetadataSource对应，
//其他的两个组件，已经在AbstractSecurityInterceptor定义
private FilterInvocationSecurityMetadataSource securityMetadataSource;
@Override
public SecurityMetadataSource obtainSecurityMetadataSource() {
return this.securityMetadataSource;
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
FilterInvocation fi = new FilterInvocation(request, response, chain);
invoke(fi);
}
private void invoke(FilterInvocation fi) throws IOException, ServletException {
// object为FilterInvocation对象
//super.beforeInvocation(fi);源码
//1.获取请求资源的权限
//执行Collection<ConfigAttribute> attributes = SecurityMetadataSource.getAttributes(object);
//2.是否拥有权限
//this.accessDecisionManager.decide(authenticated, object, attributes);
InterceptorStatusToken token = super.beforeInvocation(fi);
try {
fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
} finally {
super.afterInvocation(token, null);
}
}
public FilterInvocationSecurityMetadataSource getSecurityMetadataSource() {
return securityMetadataSource;
}
public void setSecurityMetadataSource(FilterInvocationSecurityMetadataSource securityMetadataSource) {
this.securityMetadataSource = securityMetadataSource;
}
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
public void destroy() {
// TODO Auto-generated method stub
}
@Override
public Class<? extends Object> getSecureObjectClass() {
//下面的MyAccessDecisionManager的supports方面必须放回true,否则会提醒类型错误
return FilterInvocation.class;
}
}
核心的InterceptorStatusToken token = super.beforeInvocation(fi);会调用我们定义的accessDecisionManager:decide(Object object)和securityMetadataSource :getAttributes(Object object)方法。
（2）MySecurityMetadataSource.java
//1 加载资源与权限的对应关系
public class MySecurityMetadataSource implements FilterInvocationSecurityMetadataSource {
//由spring调用
public MySecurityMetadataSource(ResourcesDao resourcesDao) {
this.resourcesDao = resourcesDao;
loadResourceDefine();
}
private ResourcesDao resourcesDao;
private static Map<String, Collection<ConfigAttribute>> resourceMap = null;
public ResourcesDao getResourcesDao() {
return resourcesDao;
}
public void setResourcesDao(ResourcesDao resourcesDao) {
this.resourcesDao = resourcesDao;
}
public Collection<ConfigAttribute> getAllConfigAttributes() {
// TODO Auto-generated method stub
return null;
}
public boolean supports(Class<?> clazz) {
// TODO Auto-generated method stub
return true;
}
//加载所有资源与权限的关系
private void loadResourceDefine() {
if(resourceMap == null) {
resourceMap = new HashMap<String, Collection<ConfigAttribute>>();
List<Resources> resources = this.resourcesDao.findAll();
for (Resources resource : resources) {
Collection<ConfigAttribute> configAttributes = new ArrayList<ConfigAttribute>();
//以权限名封装为Spring的security Object
ConfigAttribute configAttribute = new SecurityConfig(resource.getName());
configAttributes.add(configAttribute);
resourceMap.put(resource.getUrl(), configAttributes);
}
}
Set<Entry<String, Collection<ConfigAttribute>>> resourceSet = resourceMap.entrySet();
Iterator<Entry<String, Collection<ConfigAttribute>>> iterator = resourceSet.iterator();
}
//返回所请求资源所需要的权限
public Collection<ConfigAttribute> getAttributes(Object object) throws IllegalArgumentException {
String requestUrl = ((FilterInvocation) object).getRequestUrl();
System.out.println("requestUrl is " + requestUrl);
if(resourceMap == null) {
loadResourceDefine();
}
return resourceMap.get(requestUrl);
}
}
这里的resourcesDao，熟悉Dao设计模式和Spring 注入的朋友应该看得明白。
（3）MyUserDetailServiceImpl.java
public class MyUserDetailServiceImpl implements UserDetailsService {
private UsersDao usersDao;
public UsersDao getUsersDao() {
return usersDao;
}
public void setUsersDao(UsersDao usersDao) {
this.usersDao = usersDao;
}
public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
System.out.println("username is " + username);
Users users = this.usersDao.findByName(username);
if(users == null) {
throw new UsernameNotFoundException(username);
}
Collection<GrantedAuthority> grantedAuths = obtionGrantedAuthorities(users);
boolean enables = true;
boolean accountNonExpired = true;
boolean credentialsNonExpired = true;
boolean accountNonLocked = true;
User userdetail = new User(users.getAccount(), users.getPassword(), enables, accountNonExpired, credentialsNonExpired, accountNonLocked, grantedAuths);
return userdetail;
}
//取得用户的权限
private Set<GrantedAuthority> obtionGrantedAuthorities(Users user) {
Set<GrantedAuthority> authSet = new HashSet<GrantedAuthority>();
Set<Roles> roles = user.getRoles();
for(Roles role : roles) {
Set<Resources> tempRes = role.getResources();
for(Resources res : tempRes) {
authSet.add(new GrantedAuthorityImpl(res.getName()));
s }
}
return authSet;
}
}
(4) MyAccessDecisionManager.java
public class MyAccessDecisionManager implements AccessDecisionManager {
public void decide(Authentication authentication, Object object, Collection<ConfigAttribute> configAttributes) throws AccessDeniedException, InsufficientAuthenticationException {
if(configAttributes == null) {
return;
}
//所请求的资源拥有的权限(一个资源对多个权限)
Iterator<ConfigAttribute> iterator = configAttributes.iterator();
while(iterator.hasNext()) {
ConfigAttribute configAttribute = iterator.next();
//访问所请求资源所需要的权限
String needPermission = configAttribute.getAttribute();
System.out.println("needPermission is " + needPermission);
//用户所拥有的权限authentication
for(GrantedAuthority ga : authentication.getAuthorities()) {
if(needPermission.equals(ga.getAuthority())) {
return;
}
}
}
//没有权限
throw new AccessDeniedException(" 没有权限访问！ ");
}
public boolean supports(ConfigAttribute attribute) {
// TODO Auto-generated method stub
return true;
}
public boolean supports(Class<?> clazz) {
// TODO Auto-generated method stub
return true;
}
}
三、流程
1）容器启动(MySecurityMetadataSource：loadResourceDefine加载系统资源与权限列表)
2）用户发出请求
3）过滤器拦截(MySecurityFilter:doFilter)
4）取得请求资源所需权限(MySecurityMetadataSource:getAttributes)
5）匹配用户拥有权限和请求权限(MyAccessDecisionManager:decide)，如果用户没有相应的权限，
执行第6步，否则执行第7步。
6）登录
7）验证并授权(MyUserDetailServiceImpl:loadUserByUsername)
8）重复4,5
四、结束语
好了，终于写完了，回头看了一下，感觉不是怎么行。等我弄明白Spring Security它的原理之后，再回头修改下注释吧。大家觉得不妥的地方，可以留言，我会回复大家的。
原文出自：
http://blog.csdn.net/k10509806/article/details/6369131