JavaWeb合集13-HttpClient

十三、HttpClient

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。简单来说就是可以在java中构建HTTP请求。

核心API：核心API：HttpClient、HttpClients、CloseableHttpClient、HttpGet、HttpPost

发请求步骤：①发送请求步骤、②创建HttpClient对象、③调用HttpClient的execute方法发送请求

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

    @Test
    void testHttpClientGet() throws Exception {
        //1、创建HttpClient对象
      CloseableHttpClient client = HttpClients.createDefault();
      //2、创建HttpGet对象，设置url地址
        String url = "http://localhost:9091/user/shop/status";
        HttpGet get = new HttpGet(url);
        //3、使用HttpClient发送请求，获取response
       CloseableHttpResponse response =  client.execute(get);
       System.out.println("响应状态码："+response.getStatusLine().getStatusCode()); //响应状态码
        HttpEntity entity = response.getEntity(); //获取响应体
        String body= EntityUtils.toString(entity);  //转换为字符串
        System.out.println("响应数据："+body);

        //4、关闭资源
        response.close();
        client.close();
    }

    @Test
    void testHttpClientPost() throws Exception{
        //1、创建HttpClient对象
      CloseableHttpClient client =  HttpClients.createDefault();
      //2、创建HttpPost对象，设置url地址
        String url = "http://localhost:9091/admin/login";
        HttpPost post = new HttpPost(url);
        //3、设置请求参数
        JSONObject employee = new JSONObject(); //封装请求参数
        employee.put("username","admin");
        employee.put("password","123456");
        StringEntity entity =new StringEntity(employee.toString());
        //设置请求头和数据类型指定编码
        entity.setContentType("application/json");
        entity.setContentEncoding("utf-8");
        post.setEntity(entity);

        //4、使用HttpClient发送请求，获取response
       CloseableHttpResponse response =  client.execute(post);
       //5、解析响应，返回结果
        System.out.println("响应状态码："+response.getStatusLine().getStatusCode());
        HttpEntity  body =response.getEntity();
       String result = EntityUtils.toString(body); //转换为字符串
        System.out.println("响应结果："+result);

        //6、关闭资源
        response.close();
        client.close();
    }