(1). 概述
在前一篇,分析CAS自定义了一堆Filter(注意:Filter是有顺序的),在这一篇开始按照顺序对Filter源码的剖析,在这一小篇,主要剖析:ClientInfoThreadLocalFilter
(2). 看下ClientInfoThreadLocalFilter是在什么时机初始化的
@Configuration("casCoreAuditConfiguration")
@EnableAspectJAutoProxy(proxyTargetClass = true)
@EnableConfigurationProperties(CasConfigurationProperties.class)
@Slf4j
public class CasCoreAuditConfiguration {
// **************************************************************************************
// FilterRegistrationBean是Spring提供给开发使用,主要用来注册Filter的,Web容器(比如:Tomcat)会回调这些方法.
// **************************************************************************************
@Bean
public FilterRegistrationBean casClientInfoLoggingFilter() {
// cas.audit.engine
val audit = casProperties.getAudit().getEngine();
val bean = new FilterRegistrationBean<ClientInfoThreadLocalFilter>();
// Filter
bean.setFilter(new ClientInfoThreadLocalFilter());
// 过滤的请求
bean.setUrlPatterns(CollectionUtils.wrap("/*"));
bean.setName("CAS Client Info Logging Filter");
// 是支持异步
bean.setAsyncSupported(true);
// 优先级是最高的
bean.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
// 以下这些都是构建Filter需要的参数
// 定义从request中获取client的ip地址的协议头名称
// cas.audit.engine.alternateClientAddrHeaderName
val initParams = new HashMap<String, String>();
if (StringUtils.isNotBlank(audit.getAlternateClientAddrHeaderName())) {
initParams.put(ClientInfoThreadLocalFilter.CONST_IP_ADDRESS_HEADER, audit.getAlternateClientAddrHeaderName());
}
// 定义从request中获取server的ip地址的协议头名称(与useServerHostAddress是排它的)
// cas.audit.engine.alternateServerAddrHeaderName
if (StringUtils.isNotBlank(audit.getAlternateServerAddrHeaderName())) {
initParams.put(ClientInfoThreadLocalFilter.CONST_SERVER_IP_ADDRESS_HEADER, audit.getAlternateServerAddrHeaderName());
}
// 是否使用服务器的IP地址信息
// cas.audit.engine.useServerHostAddress
initParams.put(ClientInfoThreadLocalFilter.CONST_USE_SERVER_HOST_ADDRESS, String.valueOf(audit.isUseServerHostAddress()));
bean.setInitParameters(initParams);
return bean;
} // end casClientInfoLoggingFilter
}
(3). ClientInfoThreadLocalFilter
// 1. 实现:Filter
public class ClientInfoThreadLocalFilter implements Filter {
public static final String CONST_IP_ADDRESS_HEADER = "alternativeIpAddressHeader";
public static final String CONST_SERVER_IP_ADDRESS_HEADER = "alternateServerAddrHeaderName";
public static final String CONST_USE_SERVER_HOST_ADDRESS = "useServerHostAddress";
private String alternateLocalAddrHeaderName;
private boolean useServerHostAddress;
private String alternateServerAddrHeaderName;
@Override
public void destroy() {
// nothing to do here
}
@Override
public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain filterChain) throws IOException, ServletException {
try {
// 3. 创建ClientInfo对象
final ClientInfo clientInfo =
new ClientInfo((HttpServletRequest) request,
this.alternateServerAddrHeaderName,
this.alternateLocalAddrHeaderName,
this.useServerHostAddress);
// ***********************************************************************
// 4. 把ClientInfo与线程上下文进行绑定
// ***********************************************************************
ClientInfoHolder.setClientInfo(clientInfo);
// 5. 继续执行过滤器
filterChain.doFilter(request, response);
} finally {
// ***********************************************************************
// 6. 清除线程上下文信息.
// ***********************************************************************// ***********************************************************************
ClientInfoHolder.clear();
}
}
// ******************************************************************************
// 初始时,会被调用,就是上面配置的参数
// ******************************************************************************
@Override
public void init(final FilterConfig filterConfig) throws ServletException {
this.alternateLocalAddrHeaderName = filterConfig.getInitParameter(CONST_IP_ADDRESS_HEADER);
this.alternateServerAddrHeaderName = filterConfig.getInitParameter(CONST_SERVER_IP_ADDRESS_HEADER);
String useServerHostAddr = filterConfig.getInitParameter(CONST_USE_SERVER_HOST_ADDRESS);
if (useServerHostAddr != null && !useServerHostAddr.isEmpty()) {
this.useServerHostAddress = Boolean.valueOf(useServerHostAddr);
}
}
}
(4). ClientInfo
package org.apereo.inspektr.common.web;
import javax.servlet.http.HttpServletRequest;
import java.net.Inet4Address;
public class ClientInfo {
public static ClientInfo EMPTY_CLIENT_INFO = new ClientInfo();
// 服务器的ip地址信息
/** IP Address of the server (local). */
private final String serverIpAddress;
// 请求时,client的ip地址信息
/** IP Address of the client (Remote) */
private final String clientIpAddress;
private final String geoLocation;
private final String userAgent;
private ClientInfo() {
this(null);
}
public ClientInfo(final HttpServletRequest request) {
this(request, null, null, false);
}
// *************************************************************************************
// 读取request中部份信息,转换到当前模型上.
// *************************************************************************************
public ClientInfo(final HttpServletRequest request,
final String alternateServerAddrHeaderName,
final String alternateLocalAddrHeaderName,
final boolean useServerHostAddress) {
try {
String serverIpAddress = request != null ? request.getLocalAddr() : null;
String clientIpAddress = request != null ? request.getRemoteAddr() : null;
if (request == null) {
this.geoLocation = "unknown";
this.userAgent = "unknown";
} else {
// *************************************************************************************
// 1. cas.audit.engine.useServerHostAddress 与 cas.audit.engine.alternateServerAddrHeaderName 是排它的
// *************************************************************************************
if (useServerHostAddress) {
// 直接使用服务器本地的ip地址信息
serverIpAddress = Inet4Address.getLocalHost().getHostAddress();
} else if (alternateServerAddrHeaderName != null && !alternateServerAddrHeaderName.isEmpty()) {
// 从协议头获得服务器的ip的ip地址信息,如果取不到的话从request中获得localAddr
serverIpAddress = request.getHeader(alternateServerAddrHeaderName) != null ? request.getHeader(alternateServerAddrHeaderName) : request.getLocalAddr();
}
// *************************************************************************************
// 2. 读取协议头里client的ip地址信息,读取不到的情况下,获取:RemoteAddr
// *************************************************************************************
if (alternateLocalAddrHeaderName != null && !alternateLocalAddrHeaderName.isEmpty()) {
clientIpAddress = request.getHeader(alternateLocalAddrHeaderName) != null ? request.getHeader(alternateLocalAddrHeaderName) : request.getRemoteAddr();
}
// *************************************************************************************
// 3. 从请求头,获得:user-agent,如果,没有user-agent,则返回:unknown
// *************************************************************************************
String header = request.getHeader("user-agent");
this.userAgent = header == null ? "unknown" : header;
// *************************************************************************************
// 4. 从请求的参数中,获得:geolocation,如果,参数中不存在,则从协议头中获取.
// *************************************************************************************
String geo = request.getParameter("geolocation");
if (geo == null) {
geo = request.getHeader("geolocation");
}
this.geoLocation = geo == null ? "unknown" : geo;
}
// 最终赋值服务端的ip地址 和 client端的ip地址.
this.serverIpAddress = serverIpAddress == null ? "unknown" : serverIpAddress;
this.clientIpAddress = clientIpAddress == null ? "unknown" : clientIpAddress;
} catch (final Exception e) {
throw new RuntimeException(e);
}
}
// ... ...
}
(5). 总结
ClientInfoThreadLocalFilter的职责比较简单:
- 读取Request信息转换成:ClientInfo.
- 把ClientInfo与ThreadLocal进行绑定.
- 通过责任链,继续往下执行.
- 把ClientInfo与ThreadLocal进行解绑.
