HttpClient使用HttpGet进行json数据传输

JSON字符串需要用urlencoding编码
对绝大多数HTTP client而言，URL长度都有上限，所以不能传太大的JSON，一般而言几K应该没问题，但是再长点就不好说了
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.List;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.HttpStatus;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.utils.URLEncodedUtils;
 import org.apache.http.impl.client.DefaultHttpClient;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.protocol.HTTP;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.json.JSONTokener;


 /**
  * 使用HttpClient请求页面并返回json格式数据.
  * 对方接收的也是json格式数据。
  * 因此使用HttpGet。
  * */
 public class Json {

     public static void main(String[] args) throws JSONException {

         JSONObject json = new JSONObject();
         List params = new ArrayList();
         params.add(new BasicNameValuePair("Name", "123"));
         params.add(new BasicNameValuePair("Pass", "123"));
         //要传递的参数.
         String url = "http://www.----aspx?" + URLEncodedUtils.format(params, HTTP.UTF_8); // urlencoding编码
         //拼接路径字符串将参数包含进去
         json = get(url);
         System.out.println(json.get("UserId"));

     }

     public static JSONObject get(String url) {

         HttpClient client = new DefaultHttpClient();
         HttpGet get = new HttpGet(url);
         JSONObject json = null;
         try {
             HttpResponse res = client.execute(get);
             if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                 HttpEntity entity = res.getEntity();
                 json = new JSONObject(new JSONTokener(new InputStreamReader(entity.getContent(), HTTP.UTF_8)));
             }
         } catch (Exception e) {
             throw new RuntimeException(e);

         } finally{
             //关闭连接 ,释放资源
             client.getConnectionManager().shutdown();
         }
         return json;
     }
 }