SpringBoot 整合 HttpClient

第一步：引入HttpClient 的jar包

　　1、httpClient 5.0 开始支持异步（Async）请求；

　　2、httpclient 版本过低上传文件会出，原因是 org.apache.http.entity.ContentType 没有方法 withParameters(final NameValuePair... params)；

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
</dependency>
<!-- httpClient文件上传需要 -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
</dependency>

第二步：创建一个httpClient的配置类

package com.123.lenovo.adapter.se.config;

import Java.security.KeyStore;
import javax.net.ssl.SSLContext;

import org.apache.http.HeaderElement;
import org.apache.http.HeaderElementIterator;
import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustAllStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicHeaderElementIterator;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.ssl.SSLContexts;
import org.elasticsearch.Build;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.123.lenovo.adapter.se.common.IdleConnectionEvictor;

@Configuration
public class HttpClientConfig {

@Value("${http_max_total}")
    private int maxTotal = 800;
   
    @Value("${http_default_max_perRoute}")
    private int defaultMaxPerRoute = 80;
   
    @Value("${http_validate_after_inactivity}")
    private int validateAfterInactivity = 1000;
   
    @Value("${http_connection_request_timeout}")
    private int connectionRequestTimeout = 5000;
   
    @Value("${http_connection_timeout}")
    private int connectTimeout = 10000;
   
    @Value("${http_socket_timeout}")
    private int socketTimeout = 20000;
   
    @Value("${waitTime}")
    private int waitTime = 30000;
   
    @Value("${idleConTime}")
    private int idleConTime = 3;
   
    @Value("${retryCount}")
    private int retryCount = 3;
   
    @Bean
    public PoolingHttpClientConnectionManager createPoolingHttpClientConnectionManager() {
        PoolingHttpClientConnectionManager poolmanager = new PoolingHttpClientConnectionManager();
        poolmanager.setMaxTotal(maxTotal);
        poolmanager.setDefaultMaxPerRoute(defaultMaxPerRoute);
        poolmanager.setValidateAfterInactivity(validateAfterInactivity);
        return poolmanager;
    }
   
    @Bean
    public CloseableHttpClient createHttpClient(PoolingHttpClientConnectionManager poolManager) {
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create().setConnectionManager(poolManager);
        httpClientBuilder.setKeepAliveStrategy(new ConnectionKeepAliveStrategy() {
           
            @Override
            public long getKeepAliveDuration(HttpResponse response, HttpContext context) {
                HeaderElementIterator iterator = new BasicHeaderElementIterator(response.headerIterator(HTTP.CONN_KEEP_ALIVE));
                while (iterator.hasNext()) {
                    HeaderElement headerElement = iterator.nextElement();
                    String param = headerElement.getName();
                    String value = headerElement.getValue();
                    if (null != value && param.equalsIgnoreCase("timeout")) {
                        return Long.parseLong(value) * 1000;
                    }
                }
                return 30 * 1000;
            }
        });
        httpClientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler(retryCount, false));
        return httpClientBuilder.build();
    }102   
    @Bean
    public RequestConfig createRequestConfig() {
        return RequestConfig.custom()
                .setConnectionRequestTimeout(connectionRequestTimeout)    // 从连接池中取连接的超时时间
                .setConnectTimeout(connectTimeout)                        // 连接超时时间
                .setSocketTimeout(socketTimeout)                        // 请求超时时间
                .build();
    }
   
    @Bean
    public IdleConnectionEvictor createIdleConnectionEvictor(PoolingHttpClientConnectionManager poolManager) {
        IdleConnectionEvictor idleConnectionEvictor = new IdleConnectionEvictor(poolManager, waitTime, idleConTime);
        return idleConnectionEvictor;
    }
   
}

第三步：创建httpClient的工具类