让Resin HttpProxyServlet支持多域名

<servlet>
  <servlet-name>http-proxy</servlet-name>
  <servlet-class>com.caucho.servlets.HttpProxyServlet</servlet-class>
  <init host='search.chinajavaworld.com:80' />
</servlet> 
 
<servlet-mapping url-pattern="/ajax/search/*" servlet-name="http-proxy" />

<%out.print(request.getHeader("Host"));%>

search.chinajavaworld.com

search.chinajavaworld.com

<servlet>
  <servlet-name>http-proxy</servlet-name>
  <servlet-class>com.caucho.servlets.HttpProxyServlet</servlet-class>
  <init host='search.chinajavaworld.com:80' />
  <init host='search.chinajavaworld-bbb.com:80' />
</servlet> 

search.chinajavaworld-bbb.com

  public Server nextServer(String mainHost) {
Server bestServer = null;
synchronized (this) {
String _URL = null;
for (int i = 0; i < _servers.length; i++) {
Server server = _servers[i];
if (server.getURL().indexOf(mainHost) != -1) {
//System.out.println("ok,found host.return server.");
bestServer = server;
break;
}
if (i == _servers.length - 1)
  _URL = server.getURL();
}
if (bestServer == null) {
//System.out.println(mainHost+" is not in server list. add now.");
String oldMainHost = getMainDomain(_URL);
_URL = _URL.replace(oldMainHost, mainHost);
String _host = getDomain(_URL);
bestServer = new Server(_host);
_hosts.add(_host);
Server[] servers = new Server[_servers.length + 1]; 
System.arraycopy(_servers, 0, servers, 0, _servers.length);
servers[_servers.length] = bestServer;
_servers = servers;
}
return bestServer;
}
}