spring security的springSecurityFilterChain怎么初始化的

了解springSecurityFilterChain怎么初始化之前有必要先了解下　spring 的namespacehandler

http://static.springsource.org/spring/docs/2.0.x/reference/extensible-xml.html

<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>

代码实现:

public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
throws ServletException, IOException {

// Lazily initialize the delegate if necessary.
Filter delegateToUse = null;
synchronized (this.delegateMonitor) {
if (this.delegate == null) {
WebApplicationContext wac = findWebApplicationContext();
if (wac == null) {
throw new IllegalStateException("No WebApplicationContext found: no ContextLoaderListener registered?");
}
this.delegate = initDelegate(wac);
}
delegateToUse = this.delegate;
}

// Let the delegate perform the actual doFilter operation.
invokeDelegate(delegateToUse, request, response, filterChain);
}

protected Filter initDelegate(WebApplicationContext wac) throws ServletException {
Filter delegate = wac.getBean(getTargetBeanName(), Filter.class);
if (isTargetFilterLifecycle()) {
delegate.init(getFilterConfig());
}
return delegate;
}

//此方法在父类GenericFilterBean的init方法中调用的
@Override
protected void initFilterBean() throws ServletException {
synchronized (this.delegateMonitor) {
if (this.delegate == null) {
// If no target bean name specified, use filter name.
if (this.targetBeanName == null) {
　　　　　　　　　　　　　　　　　　//如果我们没有指定targetBeanName　将默认取filter的名字 即springSecurityFilterChain
this.targetBeanName = getFilterName();
}

// Fetch Spring root application context and initialize the delegate early,
// if possible. If the root application context will be started after this
// filter proxy, we'll have to resort to lazy initialization.
WebApplicationContext wac = findWebApplicationContext();
if (wac != null) {
this.delegate = initDelegate(wac);
}
}
}
}

那么springSecurityFilterChain这个bean在哪里定义的呢

spring 的namespacehander在解析http://www.springframework.org/schema/security
命名空间的http元素时创建此bean的

参考:

Spring Security3源码分析-http标签解析