HttpClient

是apache旗下的项目 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，并且支持HTTP协议最新的版本和建议
核心API

• HttpClient         
• HttpClients
• CloseableHttpClient
• HttpGet
• HttpPost

     发送请求步骤

• 创建HttpClient对象
• 创建Http请求对象
• 调用HttpClient的excute方法发送请求

HttpGet请求
 

@Test
	public void TestGet() throws IOException {
		//1.创建HttpClient对象
		CloseableHttpClient httpClient = HttpClients.createDefault();
		//2.创建Http请求对象
		HttpGet httpGet = new HttpGet("http://localhost:8080/user/shop/status");
		//3.发送请求
		CloseableHttpResponse response = httpClient.execute(httpGet) ;
			//获取请求返回的状态码
			int statusCode = response.getStatusLine().getStatusCode();
			System.out.println("返回的状态码:"+statusCode);
			//获取请求返回的数据
			HttpEntity entity = response.getEntity();
			String code = EntityUtils.toString(entity);
			System.out.println("返回的数据"+code);
		//4.关闭资源
		response.close();
		httpClient.close();
	}

Http的Post请求

@Test
	public void TestPost01() throws IOException {
		//1.创建HttpClient对象
		CloseableHttpClient httpClient = HttpClients.createDefault();
		//2.创建请求对象
		HttpPost httpPost = new HttpPost("http://localhost:8080/admin/employee/login");
		//3.发送请求
			//获取一个json对象
			JSONObject jsonObject = new JSONObject();
			//给该json赋值
			jsonObject.put("username", "admin")  ;
			jsonObject.put("password", "123456") ;
			//获取一个Entity对象
			StringEntity stringEntity = new StringEntity(jsonObject.toString()) ;
			//给post请求设置请求体
			httpPost.setEntity(stringEntity) ;
		//发送请求
		CloseableHttpResponse response = httpClient.execute(httpPost);
		System.out.println(response.getStatusLine().getStatusCode());//打印状态码
		System.out.println(EntityUtils.toString(response.getEntity())); //打印返回体字符串
		//4.关闭资源
		response.close();
		httpClient.close();
	}