httpclient工具类

import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.http.NameValuePair;
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.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
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;

httpclient.jar下载地址:http://download.csdn.net/download/cjava_math/9963817

public class HttpClientUtil {

public static String doGet(String url, Map<String, String> param) {    // 创建Httpclient对象    CloseableHttpClient httpclient = HttpClients.createDefault();    String resultString = "";    CloseableHttpResponse response = null;    try {        // 创建uri        URIBuilder builder = new URIBuilder(url);        if (param != null) {            for (String key : param.keySet()) {                builder.addParameter(key, param.get(key));            }        }        URI uri = builder.build();        // 创建http GET请求        HttpGet httpGet = new HttpGet(uri);        // 执行请求        response = httpclient.execute(httpGet);        // 判断返回状态是否为200        if (response.getStatusLine().getStatusCode() == 200) {            resultString = EntityUtils.toString(response.getEntity(), "UTF-8");        }    } catch (Exception e) {        e.printStackTrace();    } finally {        try {            if (response != null) {                response.close();            }            httpclient.close();        } catch (IOException e) {            e.printStackTrace();        }    }    return resultString;}public static String doGet(String url) {    return doGet(url, null);}public static String doPost(String url, Map<String, String> param) {    // 创建Httpclient对象    CloseableHttpClient httpClient = HttpClients.createDefault();    CloseableHttpResponse response = null;    String resultString = "";    try {        // 创建Http Post请求        HttpPost httpPost = new HttpPost(url);        // 创建参数列表        if (param != null) {            List<NameValuePair> paramList = new ArrayList<>();            for (String key : param.keySet()) {                paramList.add(new BasicNameValuePair(key, param.get(key)));            }            // 模拟表单            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);            httpPost.setEntity(entity);        }        // 执行http请求        response = httpClient.execute(httpPost);        resultString = EntityUtils.toString(response.getEntity(), "utf-8");    } catch (Exception e) {        e.printStackTrace();    } finally {        try {            response.close();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    return resultString;}public static String doPost(String url) {    return doPost(url, null);}public static String doPostJson(String url, String json) {    // 创建Httpclient对象    CloseableHttpClient httpClient = HttpClients.createDefault();    CloseableHttpResponse response = null;    String resultString = "";    try {        // 创建Http Post请求        HttpPost httpPost = new HttpPost(url);        // 创建请求内容        StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);        httpPost.setEntity(entity);        // 执行http请求        response = httpClient.execute(httpPost);        // 解析返回参数        resultString = EntityUtils.toString(response.getEntity(), "utf-8");    } catch (Exception e) {        e.printStackTrace();    } finally {        try {            response.close();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    return resultString;}

}