HttpUtil

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

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * <p>Http工具类
 * <p>1、发送GET请求；
 * <p>2、发送POST请求。
 *
 */
public class HttpUtil {
	public static String doGet(String url){
		CloseableHttpClient httpclient = HttpClients.createDefault();
		try {
			HttpGet httpget = new HttpGet(url);
			System.out.println("executing request " + httpget.getURI());
			// 执行get请求.
			CloseableHttpResponse response = httpclient.execute(httpget);
			try {
				// 获取响应实体
				HttpEntity entity = response.getEntity();
				System.out.println("--------------------------------------");
				// 打印响应状态
				System.out.println(response.getStatusLine());
				if (entity != null) {
					return EntityUtils.toString(entity);
				}
				System.out.println("------------------------------------");
			} finally {
				response.close();
			}
		}catch (Exception e) {
			e.printStackTrace();
		} finally {
			// 关闭连接,释放资源
			try {
				httpclient.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return null;
	}

	/**
	 * post方式提交表单（模拟用户登录请求）
	 */
	public String postForm(String url,Map<String,String> params) {
		// 创建默认的httpClient实例.
		CloseableHttpClient httpclient = HttpClients.createDefault();
		HttpPost httppost = new HttpPost(url);
		// 创建参数队列
		List<BasicNameValuePair> formparams = new ArrayList<BasicNameValuePair>();
		for (Map.Entry<String, String> entry : params.entrySet()) {
			  formparams.add(new BasicNameValuePair( entry.getKey(),  entry.getValue()));
			}
		UrlEncodedFormEntity uefEntity;
		try {
			uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
			httppost.setEntity(uefEntity);
			System.out.println("executing request " + httppost.getURI());
			CloseableHttpResponse response = httpclient.execute(httppost);
			try {
				HttpEntity entity = response.getEntity();
				if (entity != null) {
					return EntityUtils.toString(entity, "UTF-8");
				}
			} finally {
				response.close();
			}
		} catch (ClientProtocolException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			// 关闭连接,释放资源
			try {
				httpclient.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return null;
	}

}