301，302 都是http狀态的編碼，都代表着某個url發生了轉移，不同之處在于：
301 redirect: 301 代表永久性轉移(permanently moved)。
302 redirect: 302 代表暫時性轉移(temporarily moved )。
這是很官方的說法，那麼它們的差別到底是什麼呢？
這裡隻說解決方法，不針對這2個狀态進行詳解。
/**
* 執行post送出
*
* @return
* @author shanhy
*/
private static string getpostresponse(string url, part[] parts) {
postmethod mpost = new postmethod(url);
mpost.addrequestheader("content", "text/html,charset=gbk");
mpost.setrequestentity(new multipartrequestentity(parts, mpost.getparams()));
try {
int statuscode = httpclient.executemethod(mpost);
string responsebody = "";
if (statuscode == httpstatus.sc_moved_permanently || statuscode == httpstatus.sc_moved_temporarily) {
header locationheader = mpost.getresponseheader("location");
string location = null;
if (locationheader != null) {
location = locationheader.getvalue();
responsebody = getpostresponse(location, parts);// 用跳轉後的頁面重新請求。
}
} else if (statuscode == httpstatus.sc_ok) {
responsebody = mpost.getresponsebodyasstring();
}
// system.out.println(responsebody);
if (statuscode == httpstatus.sc_ok) {// 成功
return null;
mpost.releaseconnection();
return responsebody;
} catch (httpexception e) {
e.printstacktrace();
} catch (unsupportedencodingexception e) {
} catch (ioexception e) {
}
return null;
}