连接池

package cn.lala.crawler.httpclient.test;import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
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.util.EntityUtils;import java.io.IOException;@SuppressWarnings("all")
public class HttpClientPoolManagerTest {public static void main(String[] args) throws IOException {//创建连接池管理器PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();//设置最大连接数connectionManager.setMaxTotal(200);//设置每个主机的最大连接数，指定访问每一个网站的连接数，不会影响其他网站的访问connectionManager.setDefaultMaxPerRoute(20);//使用连接池管理器获取连接并发起请求get(connectionManager);get(connectionManager);//}private static void get(PoolingHttpClientConnectionManager connectionManager) throws IOException {//使用连接池管理器获取连接CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(connectionManager).build();//打印连接，如果两次打印的内存的地址值不一样，证明是不同的连接//org.apache.http.impl.client.InternalHttpClient@5af3afd9//org.apache.http.impl.client.InternalHttpClient@33f676f6System.out.println(httpClient);//HttpGet httpGet = new HttpGet("https://www.baidu.com");CloseableHttpResponse response = httpClient.execute(httpGet);if(response.getStatusLine().getStatusCode()==200){String html = EntityUtils.toString(response.getEntity(), "UTF-8");System.out.println("请求成功，数据的长度是:"+html.length());}}
}

设置请求参数

package cn.lala.crawler.httpclient.test;import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;import java.io.IOException;@SuppressWarnings("all")
public class HttpClientRequestConfigTest {public static void main(String[] args) {CloseableHttpClient httpClient = HttpClients.createDefault();//不带参数的get请求HttpGet httpGet = new HttpGet("https://www.baidu.com/"); //创建连接请求参数//构建请求配置信息RequestConfig config = RequestConfig.custom().setConnectTimeout(1000)//创建连接的最长时间.setConnectionRequestTimeout(500)//从连接池获取连接的最长时间.setSocketTimeout(10 * 1000)//设置传输数据的最长时间.build();//把请求参数设置到httpGet中httpGet.setConfig(config);CloseableHttpResponse response = null;try {response = httpClient.execute(httpGet);if (response.getStatusLine().getStatusCode() == 200) {String html = EntityUtils.toString(response.getEntity(), "UTF-8");System.out.println("请求成功，数据的长度是:" + html.length());}} catch (IOException e) {throw new RuntimeException(e);} finally {if (response != null) {try { //关闭responseresponse.close();//关闭httpClienthttpClient.close();} catch (IOException e) {throw new RuntimeException(e);}}}}
}