springboot使用RestTemplate+httpclient连接池发送http消息

简介

1. RestTemplate是spring支持的一个请求http rest服务的模板对象，性质上有点像jdbcTemplate
2. RestTemplate底层还是使用的httpclient（org.apache.http.client.HttpClient）发送请求的
3. HttpClient可以做连接池，而发送消息的工具类可以使用RestTemplate，所以如果你的项目需求http连接池，RestTemplate+httpclient连接池是一种不错的方式，可以节省开发工作，也可以更优雅的使用。

 

配置

1. maven依赖
   
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   <dependency>             <groupId>org.apache.httpcomponents</groupId>             <artifactId>httpclient</artifactId>             <version>4.5.6</version> </dependency>   <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId> </dependency>

   　　

2. Java配置类
   
   
   
   
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   package com.jinjian.rt.config;   import lombok.Data; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component;   @Component @ConfigurationProperties(prefix = "http-pool") @Data public class HttpPoolProperties {       private Integer maxTotal;     private Integer defaultMaxPerRoute;     private Integer connectTimeout;     private Integer connectionRequestTimeout;     private Integer socketTimeout;     private Integer validateAfterInactivity;   }

   　　
   
   
   
   

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   package com.jinjian.rt.config;   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.beans.factory.annotation.Autowired; 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;   @Configuration public class RestTemplateConfig {       @Autowired     private HttpPoolProperties httpPoolProperties;       @Bean     public RestTemplate restTemplate() {         return new RestTemplate(httpRequestFactory());     }       @Bean     public ClientHttpRequestFactory httpRequestFactory() {         return new HttpComponentsClientHttpRequestFactory(httpClient());     }       @Bean     public HttpClient httpClient() {         Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()                 .register("http", PlainConnectionSocketFactory.getSocketFactory())                 .register("https", SSLConnectionSocketFactory.getSocketFactory())                 .build();         PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(registry);         connectionManager.setMaxTotal(httpPoolProperties.getMaxTotal());         connectionManager.setDefaultMaxPerRoute(httpPoolProperties.getDefaultMaxPerRoute());         connectionManager.setValidateAfterInactivity(httpPoolProperties.getValidateAfterInactivity());         RequestConfig requestConfig = RequestConfig.custom()                 .setSocketTimeout(httpPoolProperties.getSocketTimeout()) //服务器返回数据(response)的时间，超过抛出read timeout                 .setConnectTimeout(httpPoolProperties.getConnectTimeout()) //连接上服务器(握手成功)的时间，超出抛出connect timeout                 .setConnectionRequestTimeout(httpPoolProperties.getConnectionRequestTimeout())//从连接池中获取连接的超时时间，超时间未拿到可用连接，会抛出org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool                 .build();         return HttpClientBuilder.create()                 .setDefaultRequestConfig(requestConfig)                 .setConnectionManager(connectionManager)                 .build();     } }

   　　

3. 使用方法

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   package com.jinjian.rt.service;   import com.jinjian.rt.dto.RuiooResponseEntity; import org.json.JSONException; import org.json.JSONObject; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.ResponseEntity; import org.springframework.stereotype.Service; import org.springframework.web.client.RestTemplate;   import java.io.IOException;   @Service public class TestService {       @Autowired     private RestTemplate restTemplate;       public void startTest() throws JSONException, IOException {           JSONObject jsonObject = new JSONObject();         jsonObject.put("first","jinjian");         jsonObject.put("second","aaaaaaa");           long start = System.currentTimeMillis();         //{1} 表示第一个占位符，也可以填写name,但是这是另一个getForEntity重载方法         //RuiooResponseEntity 为自定义dto         ResponseEntity<RuiooResponseEntity> entity = restTemplate.getForEntity("http://39.107.104.221/api/test/{1}", RuiooResponseEntity.class, 123);         long end = System.currentTimeMillis();         long cost = end - start;         System.out.println("耗时："+cost);         RuiooResponseEntity body = entity.getBody();         body.getData();         body.getStatus();         body.getMessage();         System.out.println("响应体："+ body);     } }