RestTemplate 配置链接池

一、添加依赖

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.9</version>
    <scope>compile</scope>
</dependency>

 二、配置

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.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
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.web.client.RestTemplate;

/**
 * http请求配置
 */
@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate httpRestTemplate() {
        ClientHttpRequestFactory factory = httpRequestFactory();
        RestTemplate restTemplate = new RestTemplate(factory);
        // 能够添加消息转换
        //restTemplate.setMessageConverters(...);
        // 能够增长拦截器
        //restTemplate.setInterceptors(...);
        return restTemplate;
    }

    public ClientHttpRequestFactory httpRequestFactory() {
        return new HttpComponentsClientHttpRequestFactory(restTemplateConfigHttpClient());
    }

    public HttpClient restTemplateConfigHttpClient() {
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();
        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(registry);
        // 设置整个链接池最大链接数 根据本身的场景决定
        // todo 后面调整从配置中心获取
        connectionManager.setMaxTotal(200);
        // 路由是对maxTotal的细分
        // todo 后面调整从配置中心获取
        connectionManager.setDefaultMaxPerRoute(100);
        RequestConfig requestConfig = RequestConfig.custom()
                // 服务器返回数据(response)的时间，超过该时间抛出read timeout
                // todo 后面调整从配置中心获取
                .setSocketTimeout(10000)
                // 链接上服务器(握手成功)的时间，超出该时间抛出connect timeout
                // todo 后面调整从配置中心获取
                .setConnectTimeout(5000)
                // 从链接池中获取链接的超时时间，超过该时间未拿到可用链接，
                // 会抛出org.apache.http.conn.ConnectionPoolTimeoutException:
                // Timeout waiting for connection from pool
                // todo 后面调整从配置中心获取
                .setConnectionRequestTimeout(5000)
                .build();
        return HttpClientBuilder.create()
                .setDefaultRequestConfig(requestConfig)
                .setConnectionManager(connectionManager)
                .build();
    }
}