org.apache.http.client.HttpClient

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import org.apache.http.HttpResponse;

import org.apache.http.NameValuePair;

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.protocol.HTTP;

import org.apache.http.util.EntityUtils;

public class HttpClientTests {

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

HttpClient client=new DefaultHttpClient();

//POST url

String posturl="http://localhost:8080/a.action";

//建立HttpPost对象

HttpPost httpPost=new HttpPost(posturl);

//建立一个NameValuePair数组，用于存储欲传递的参数

List params=new ArrayList();

//添加参数

params.add(new BasicNameValuePair("start", "0"));

params.add(new BasicNameValuePair("size", "14"));

params.add(new BasicNameValuePair("sortType", "hot"));

//设置编码

httpPost.setEntity(new UrlEncodedFormEntity(params,HTTP.UTF_8));

//发送Post,并返回一个HttpResponse对象  

HttpResponse response=new DefaultHttpClient().execute(httpPost);

//可以得到指定的header

//      Header header = response.getFirstHeader("Content-Length");

// String Length=header.getValue(); 

// System.out.println(header.getName());

//如果状态码是200，则正常返回

if(response.getStatusLine().getStatusCode()==200){

//获得返回的字符串

String result=EntityUtils.toString(response.getEntity());

//打印输出

System.err.println(result);

//如果是下载的文件，可以用response.getEntity().getContent返回InputStream 

}

}

}