前言介绍

总结就是使得可以在java程序中发送http请求。

 

 导入依赖

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

发送get请求

用到如下的一个url，不需要参数

https://yapi.pro/mock/17601/yhy2002

每次会返回一些不同的字符串。

代码如下所示

    @Test
    void testGet() throws IOException {
        //创建httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //创建请求对象
        HttpGet httpGet = new HttpGet("https://yapi.pro/mock/17601/yhy2002");
        //发送请求
        CloseableHttpResponse response = httpClient.execute(httpGet);

        //获取服务端返回的状态码
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);

        //获取响应数据
        HttpEntity entity = response.getEntity();
        //解析响应
        String s = EntityUtils.toString(entity);
        System.out.println(s);

                //关闭资源
        response.close();
        httpClient.close();    
    }

输出有:

 发送post请求

使用到如下的链接

https://yapi.pro/mock/17601/yhy2003

需要两个参数username，password,还有指定contentType为application/json，这里不需要指定编码格式

 @Test
    void testPost() throws IOException, JSONException {
        //创建httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //创建请求对象
        HttpPost httpPost = new HttpPost("https://yapi.pro/mock/17601/yhy2003");

        //将json格式参数转换字符串
        JSONObject jsonObject=new JSONObject();
        jsonObject.put("username","yhy");
        jsonObject.put("password","123456");
        StringEntity stringEntity=new StringEntity(jsonObject.toString());

        //指定编码方式
      //  stringEntity.setContentEncoding("utf-8");
        //指定数据格式
        stringEntity.setContentType("application/json");
        //设置请求参数
        httpPost.setEntity(stringEntity);


        //发送请求
        CloseableHttpResponse response = httpClient.execute(httpPost);

        //获取服务端返回的状态码
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);

        //获取响应数据
        HttpEntity entity = response.getEntity();
        //解析响应
        String s = EntityUtils.toString(entity);
        System.out.println(s);

        //关闭资源
        response.close();
        httpClient.close();
    }

输出为随机字符串