使用jetty 自带的http client！

一般情况下我们需要使用HttpClient时可供选择的技术有：
1、HttpURLConnection
2、Apache HttpClient
其他的除了写Socket 我都没有用过了。

偶然的机会发现Jetty 里面也自带了一个HttpClient，并且支持事件触发的处理方式。

HttpClient client = new HttpClient();
client.setConnectorType(HttpClient.CONNECTOR_SELECT_CHANNEL);
try
{
  client.start();
}
catch (Exception e)
{
  throw new ServletException(e);
}

// create the exchange object, which lets you define where you want to go
// and what you want to do once you get a response
ContentExchange exchange = new ContentExchange()
{
  // define the callback method to process the response when you get it back
  protected void onResponseComplete() throws IOException
  {
    super.onResponseComplete();
    String responseContent = this.getResponseContent();

    // do something with the response content
    ...
  }
};

exchange.setMethod("GET");
exchange.setURL("http://www.example.com/");

// start the exchange
client.send(exchange);

还可以使用同步的处理方式：

public static void main(String[] args)
        {
		HttpClient httpClient = new HttpClient();
                //set up httpClient
                httpClient.start();
		ContentExchange contentExchange = new ContentExchange();
                httpClient.setConnectorType(HttpClient.CONNECTOR_SELECT_CHANNEL);
		contentExchange.setURL("http://slashdot.org");
                httpClient.send();
                contentExchange.waitForDone();
		System.err.println("Response status: "+contentExchange.getResponseStatus());
	}

还可以方便的设置Proxy网关：

client.setProxy(new Address("proxy_address",proxy_port));
client.setProxyAuthentication(new ProxyAuthorization("user","password"));

jetty http client 感觉不错，比Apache HttpClient更加易用、小巧！