工作是spring 项目一般都是使用ResTemplate 但是还是有些项目中会用到httpClient，没有毛用。

 <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>${httpclient.vesion}</version>
        </dependency>

package com.example.demo;import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.util.Date;
import java.util.UUID;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;import javax.xml.ws.spi.http.HttpContext;import org.apache.http.Header;
import org.apache.http.HeaderIterator;
import org.apache.http.ProtocolVersion;
import org.apache.http.RequestLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.params.HttpParams;
import org.springframework.boot.autoconfigure.elasticsearch.jest.HttpClientConfigBuilderCustomizer;import com.alibaba.fastjson.JSON;
import com.example.demo.domain.User;
import com.fasterxml.jackson.annotation.JsonFormat;public class HttpClient {public static void main(String[] args) {ThreadPoolExecutor executor = new ThreadPoolExecutor(20, 20, 30,TimeUnit.SECONDS, new LinkedBlockingDeque());for(int i = 1; i<100; i++) {HttpClientBuilder builder = HttpClientBuilder.create();CloseableHttpClient client = builder.build();HttpPost request = new HttpPost("http://localhost:9090/user/save");User user = new User();user.setUserName(UUID.randomUUID().toString().substring(0,10));user.setAge(i%100);user.setPassword(UUID.randomUUID().toString());Date date = new Date();user.setCreateDate(date);user.setUpdateDate(new Date());executor.submit(()-> {try {request.setEntity(new StringEntity(JSON.toJSONString(user)));request.setHeader("content-type","application/json;charset=UTF-8");CloseableHttpResponse response = client.execute(request);client.close();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}});}}
}

2.okHttpClient

3.restTemplate