1.介绍

HttpClient是Apache Jakarta Common下的子项目，可以用来提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包，并且它支持HTTP协议最新的版本和建议

依赖：

核心API：

①HTTPClient

②HTTPClients

③CloseableHttpClient

④HttpGet

⑤HttpPost

发送请求步骤：

①创建HttpClient对象

②创建Http请求对象

③调用HttpClient的execute方法发送请求

2.入门案例

发送Get请求方法代码：

/***  测试通过httpclient发送Get方式的请求*/@Testpublic void testGET()throws Exception{//创建httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//创建请求对象HttpGet httpGet = new HttpGet("http://localhost:8080/user/shop/status");//发送请求,接受响应结果CloseableHttpResponse response = httpClient.execute(httpGet);//获取服务端返回的状态码int statusCode = response.getStatusLine().getStatusCode();System.out.println("服务端返回的状态码为："+statusCode);HttpEntity entity = response.getEntity();String body = EntityUtils.toString(entity);System.out.println("服务端返回的数据为："+body);//关闭资源response.close();httpClient.close();}

发送Post请求方法代码：

/***  测试通过httpclient发送Get方式的请求*/@Testpublic void testPost()throws Exception{//创建httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//创建请求对象HttpPost httpPost = new HttpPost("http://localhost:8080/admin/employee/login");JSONObject jsonObject = new JSONObject();jsonObject.put("username","admin");jsonObject.put("password","123456");StringEntity entity = new StringEntity(jsonObject.toString());//指定请求编码方式entity.setContentEncoding("utf-8");//数据格式entity.setContentType("application/json");httpPost.setEntity(entity);//发送请求CloseableHttpResponse response = httpClient.execute(httpPost);//解析返回结果int statusCode = response.getStatusLine().getStatusCode();System.out.println("响应码为："+ statusCode);HttpEntity entity1 = response.getEntity();String body = EntityUtils.toString(entity1);System.out.println("响应数据为："+body);//关闭资源response.close();httpClient.close();}