java模擬httppost遇到以下問題：

java.lang.NoClassDefFoundError: org/apache/http/params/SyncBasicHttpParams

package httpPost;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

public class TestH2 {
	public static void main(String[] args) {
		String url = "XXXXXX";
		String result = null;
		HttpPost httpRequst = new HttpPost(url);
		
		List<NameValuePair> params = new ArrayList<NameValuePair>();

		///
		HttpParams httpParameters = new BasicHttpParams();
		HttpConnectionParams.setConnectionTimeout(httpParameters, 10 * 1000);// 設定請求超時10秒
		HttpConnectionParams.setSoTimeout(httpParameters, 10 * 1000); // 設定等待資料超時10秒
		HttpConnectionParams.setSocketBufferSize((HttpParams) params, 8192);
		HttpClient httpclient = new DefaultHttpClient(httpParameters); // 此時構造DefaultHttpClient時將引數傳入
		///

		params.add(new BasicNameValuePair("str", "i am post string"));
		try {
			httpRequst.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
			
			HttpResponse httpResponse = new DefaultHttpClient().execute(httpRequst);
			
			if (httpResponse.getStatusLine().getStatusCode() == 200) {
				
				HttpEntity httpEntity = httpResponse.getEntity();
				result = EntityUtils.toString(httpEntity);// 取出應答字串
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			result = e.getMessage().toString();
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			result = e.getMessage().toString();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			result = e.getMessage().toString();
		}
		System.out.println(result);
	}
}