HttpClient 3_configuration

想多了解的人, 當然, 自己多看看 Java Doc 囉.
以下列出幾個常用的.

1. Add Headers

    GetMethod method = new GetMethod();
    method.addRequestHeader("headerName", "headerValue");
    // or 
    method.addRequestHeader(new Header("headerName", "headerValue"));

2. 設定 timeout 時間

    HttpMethodParams params = new HttpMethodParams();
    params.setSoTimeout(3000);

    // or 
    method.getParams().setSoTimeout(3000);

3. 多執行序下使用 HttpClient

    HttpClient client = new HttpClient(new MultiThreadedHttpConnectionManager());
    // or 
    MultiThreadedHttpConnectionManager config = new MultiThreadedHttpConnectionManager());
    // set other config
    HttpClient client = new HttpClient();
    client.setHttpConnectionManager(config);

補充: 如果您的程式會一直使用 httpclient 發送 request, 建意將 httpclient 宣告成只有一份(ex: static or singleton), 減少不必要要的 port 被開啟, 又要等待 system close.

4. 失敗時, retry 3 次

    // set per default
    client.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, 
new DefaultHttpMethodRetryHandler()); 
    // or 
    DefaultMethodRetryHandler retryhandler = new DefaultMethodRetryHandler(10, true);
    client.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, retryhandler);

    // 如果想了解哪些情況下, 才會 retry, 請參考官網 http://hc.apache.org/httpclient-3.x/tutorial.html
  

目前這些囉, 有想到什麼常用的到時候再補充唷.