HttpClient4.5，连接池使用示例

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

import javax.net.ssl.SSLContext;

import org.apache.http.Consts;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
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.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
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.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

public class HttpClientUtil {
	
	private static PoolingHttpClientConnectionManager connManager = null;
	
	static{
		LayeredConnectionSocketFactory sslsf = null;
        try {
            sslsf = new SSLConnectionSocketFactory(SSLContext.getDefault());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        
        Registry
 
   socketFactoryRegistry = RegistryBuilder.
  
    create() .register("http", PlainConnectionSocketFactory.getSocketFactory()) .register("https", sslsf) .build(); connManager =new PoolingHttpClientConnectionManager(socketFactoryRegistry); connManager.setMaxTotal(200); connManager.setDefaultMaxPerRoute(50); } private static CloseableHttpClient getHttpClient() { RequestConfig requestConfig = RequestConfig.custom() .setConnectTimeout(3000) // 连接超时 .setSocketTimeout(3000) // 数据读取超时 .setConnectionRequestTimeout(5000) // 从连接池获取连接的超时时间 .build(); CloseableHttpClient httpClient = HttpClients.custom() .setConnectionManager(connManager) .setDefaultRequestConfig(requestConfig) .build(); return httpClient; } private HttpClientUtil() {}; public static String doGet(String url, Map
   
     params) { // 创建Httpclient对象 CloseableHttpClient httpClient = getHttpClient(); String resultString = ""; CloseableHttpResponse response = null; try { // 创建uri URIBuilder builder = new URIBuilder(url); if (params != null) { for (String key : params.keySet()) { builder.addParameter(key, params.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(), Consts.UTF_8); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (response != null) { response.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
    
      params) { // 创建Httpclient对象 CloseableHttpClient httpClient = getHttpClient(); CloseableHttpResponse response = null; String resultString = ""; try { // 创建Http Post请求 HttpPost httpPost = new HttpPost(url); // 创建参数列表 if (params != null) { List
     
       paramList = new ArrayList<>(); for (String key : params.keySet()) { paramList.add(new BasicNameValuePair(key, params.get(key))); } // 模拟表单 UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList,Consts.UTF_8); httpPost.setEntity(entity); } // 执行http请求 response = httpClient.execute(httpPost); resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8); } catch (Exception e) { e.printStackTrace(); } finally { try { if (response != null) { response.close(); } } catch (IOException e) { 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 = getHttpClient(); 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); resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8); } catch (Exception e) { e.printStackTrace(); } finally { try { if (response != null) { response.close(); } } catch (IOException e) { e.printStackTrace(); } } return resultString; } }