HttpClient使用

引入jar

<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.4</version>
		</dependency>

工具类

package top.lilixin.util;/**
 * Created by lilixin on 08/08/2017.
 */

/**
 * @author lilixin
 * @create 2017-08-08 3:18 PM
 **/

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
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;

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

public class HttpClientUtil {
    /**
     * 发送 post请求访问本地应用并根据传递参数不同返回不同结果
     */
    public static String post(String url,Map<String,String> params) {

        // 创建默认的httpClient实例.
        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建httppost
        HttpPost httppost = new HttpPost(url);
        // 创建参数队列
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        for (String pkey : params.keySet()) {
            formparams.add(new BasicNameValuePair(pkey, params.get(pkey)));
        }

        UrlEncodedFormEntity uefEntity;
        try {
            uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
            httppost.setEntity(uefEntity);
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    return EntityUtils.toString(entity, "UTF-8");
                }
            } finally {
                if(response != null){
                    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 {
                if(httpclient != null){
                    httpclient.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /**
     * 发送 get请求
     */
    public static String get(String url) {
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            // 创建httpget.
            HttpGet httpget = new HttpGet(url);
            // 执行get请求.
            CloseableHttpResponse response = null;
            try {
                response = httpclient.execute(httpget);
                // 获取响应实体
                HttpEntity entity = response.getEntity();
                // 打印响应状态
                if (entity != null) {
                    return EntityUtils.toString(entity);
                }

            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (ParseException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

            return null;

        }finally {
            if (httpclient != null){
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}