HTTPClient使用

平时工作中难免需要调用http接口来获取数据，尤其对于json的标准数据。一下为在httpclient4.2中使用的方式

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
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.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.PoolingClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;

public class HttpClientGetTest {
	static String url = "http://localhost/index.do";
	private static PoolingClientConnectionManager cm = new PoolingClientConnectionManager();
	private static HttpClient hc = new DefaultHttpClient(cm);

	public static void main(String[] args) {
		cm.setMaxTotal(100);
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("action", "aaa"));
//增加请求参数
		params.add(new BasicNameValuePair("name", "true"));
		
		String body = post(url, params);
		long startTime = new Date().getTime();
		body = get(url, params);
		System.out.println(new Date().getTime() - startTime);
		body = get(url, params);
		System.out.println(new Date().getTime() - startTime);
		body = get(url, params);
		System.out.println(new Date().getTime() - startTime);
		body = get(url, params);
		System.out.println(new Date().getTime() - startTime);
		System.out.println(body);
		hc.getConnectionManager().shutdown();
	}

	/**
	 * // Post请求 貌似post不能用
	 * 
	 * @param url
	 * @param params
	 * @return
	 */
	public static String post(String url, List<NameValuePair> params) {
		String body = null;
		try {
			// Post请求
			HttpPost httppost = new HttpPost(url);
			// 设置参数
			httppost.setEntity(new UrlEncodedFormEntity(params, "utf-8"));
			// 发送请求
			HttpResponse httpresponse = hc.execute(httppost);
			// 获取返回数据
			HttpEntity entity = httpresponse.getEntity();
			body = EntityUtils.toString(entity);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (ClientProtocolException e) {
			e.printStackTrace();
		} catch (ParseException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return body;
	}
	/**
	 * Get请求
	 * 
	 * @param url
	 * @param params
	 * @return
	 */
	public static String get(String url, List<NameValuePair> params) {
		String body = null;
		try {
			// Get请求
			HttpGet httpget = new HttpGet(url);
			// 设置参数
			String str = EntityUtils.toString(new UrlEncodedFormEntity(params,
					"utf-8"));
			// for (NameValuePair nameValuePair : params) {
			// httppost.getParams().setParameter(nameValuePair.getName(),
			// nameValuePair.getValue());
			// }
			// httpget.setURI(new URI(httpget.getURI().toString() + "?" +
			// URLEncodedUtils.format(params, "UTF-8")));
			httpget.setURI(new URI(httpget.getURI().toString() + "?" + str));
			// 发送请求
			HttpContext context = new BasicHttpContext();
			HttpResponse httpresponse = hc.execute(httpget, context);
			// 获取返回数据
			HttpEntity entity = httpresponse.getEntity();
			body = EntityUtils.toString(entity);
			
		} catch (ParseException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (URISyntaxException e) {
			e.printStackTrace();
		}finally{
			httpget.releaseConnection();
		}
		return body;
	}
}