1. 依赖：

<dependency>
    <groupId>org.apache.httpcomponents</groupId>            
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>

2.使用

package com.sky;

import lombok.extern.slf4j.Slf4j;
import netscape.javascript.JSObject;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import javax.swing.text.html.parser.Entity;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

@Slf4j
@SpringBootTest
public class TestHttpClient {

    @Test
    public void doGet () throws IOException {
        //1.创建HttpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //2.创建HttpGet对象
        HttpGet httpGet = new HttpGet("http://localhost:8080/user/shop/status");
        //3.使用HttpClient发起请求
        CloseableHttpResponse response = httpClient.execute(httpGet);
        //4.解析响应
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);
        //5.获取响应体
        HttpEntity entity = response.getEntity();
        System.out.println(entity);
        //6.获取响应内容
        String string = EntityUtils.toString(entity);
        System.out.println(string);
        //6.关闭资源
        httpClient.close();
        response.close();
    }


    @Test
    public void doPost() throws JSONException, IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost("http://localhost:8080/admin/employee/login");

        //设置请求体
        JSONObject jsonObject=new JSONObject();
        jsonObject.put("username","admin");
        jsonObject.put("password","123456");
        StringEntity stringEntity = new StringEntity(jsonObject.toString());
        stringEntity.setContentEncoding("UTF-8");
        stringEntity.setContentType("application/json");
        httpPost.setEntity(stringEntity);

        //发起请求
        CloseableHttpResponse response = httpClient.execute(httpPost);
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println("statusCode = " + statusCode);

        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity);
        System.out.println("string = " + string);

    }

}