android httpclient请求数据关闭问题

/**
 * 数据请求
 * 
 * @param url
 * @return
 */
public static String queryStringForPost(String url) {

// String s_url = ""; String realurl = s_url + url;
HttpPost request = HttpUtil.getHttpPost(realurl);
String result = null;
try {
HttpResponse response = HttpUtil.getHttpResponse(request);
if (response.getStatusLine().getStatusCode() == 200) { result = EntityUtils.toString(response.getEntity());
return result;
}
} catch (ClientProtocolException e) {
e.printStackTrace();
result = "网络异常！";
return result;
} catch (IOException e) {
e.printStackTrace();
result = "网络异常！";
return result;
}
return null;
} // 异常的方法
public static HttpResponse getHttpResponse(HttpPost request)
throws ClientProtocolException, IOException {
HttpResponse response = new DefaultHttpClient().execute(request);
return response;
} /**
 * 此应用所有网络连接使用一个httpClient
 * 
 * @return
 */
private HttpClient createHttpClient() {
Log.i(APP, "CREATE HTTPCLIENT");
HttpParams httpParams = new BasicHttpParams();
HttpProtocolParams.setVersion(httpParams, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(httpParams,
HTTP.DEFAULT_CONTENT_CHARSET);
HttpProtocolParams.setUseExpectContinue(httpParams, true); /* 连接超时 */
HttpConnectionParams.setConnectionTimeout(httpParams, 1000);
/* 请求超时 */
HttpConnectionParams.setSoTimeout(httpParams, 4000); SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(new Scheme("https", SSLSocketFactory
.getSocketFactory(), 443));
schemeRegistry.register(new Scheme("http", PlainSocketFactory
.getSocketFactory(), 80));
// 关键代码--事关线程安全。
ClientConnectionManager clientConnectionManager = new ThreadSafeClientConnManager(
httpParams, schemeRegistry);
return new DefaultHttpClient(clientConnectionManager, httpParams);
} public HttpClient getHttpClient() {
return httpClient;
} @Override
public void onLowMemory() { super.onLowMemory();
shutdownHttpClient();
} @Override
public void onTerminate() { super.onTerminate();
shutdownHttpClient();
} private void shutdownHttpClient() {
if (httpClient != null && httpClient.getConnectionManager() != null) {
httpClient.getConnectionManager().shutdown();
} }