性能优化之 http连接池化

代码如下 优化原理就是原本的http连接是通过SimpleClientHttpRequestFactory创建（已注释）

每来一个请求就新创建一个，这里做到连接的复用

import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.web.client.RestTemplate;

/**
 * 小滴课堂,愿景：让技术不再难学
 *
 * @Description
 * @Author 二当家小D
 * @Remark 有问题直接联系我，源码-笔记-技术交流群
 * @Version 1.0
 **/

@Configuration
@EnableAsync
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory requestFactory){
        return new RestTemplate(requestFactory);
    }

//    @Bean
//    public ClientHttpRequestFactory clientHttpRequestFactory(){
//        SimpleClientHttpRequestFactory factory  = new SimpleClientHttpRequestFactory();
//        factory.setReadTimeout(10000);
//        factory.setConnectTimeout(10000);
//        return factory;
//    }

    @Bean
    public ClientHttpRequestFactory clientHttpRequestFactory(HttpClient httpClient){
        return  new HttpComponentsClientHttpRequestFactory(httpClient);
    }

    @Bean
    public HttpClient httpClient(){
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();

        //设置连接池最大是500个连接
        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
        connectionManager.setMaxTotal(500);
        //MaxPerRoute是对maxtotal的细分，每个主机的并发最大是300，route是指域名
        connectionManager.setDefaultMaxPerRoute(300);
        /**
         * 只请求 xdclass.net,最大并发300
         *
         * 请求 xdclass.net,最大并发300
         * 请求 open1024.com,最大并发200
         *
         * //MaxtTotal=400 DefaultMaxPerRoute=200
         * //只连接到http://xdclass.net时，到这个主机的并发最多只有200；而不是400；
         * //而连接到http://xdclass.net 和 http://open1024.com时，到每个主机的并发最多只有200；
         * // 即加起来是400（但不能超过400）；所以起作用的设置是DefaultMaxPerRoute。
         *
         */

        RequestConfig requestConfig = RequestConfig.custom()
                //返回数据的超时时间
                .setSocketTimeout(20000)
                //连接上服务器的超时时间
                .setConnectTimeout(10000)
                //从连接池中获取连接的超时时间
                .setConnectionRequestTimeout(1000)
                .build();

        CloseableHttpClient closeableHttpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig)
                .setConnectionManager(connectionManager)
                .build();

        return closeableHttpClient;
    }
}