HttpClient中的各类请求

一:什么是HttpClient？

主要是模拟浏览器发送请求给server，监听响应信息，推断返回结果的正确性怎样，由于避开的浏览器的UI 
，也就将浏览器中所有载入的时间（比方经常要载入图片啊）都省掉了，因此这个运行效率至关高

二. 使用HttpClient

1.get请求

@Test
    public void doGet() throws Exception {
        //建立一个httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //建立一个GET对象
        HttpGet get = new HttpGet("http://www.sogou.com");
        //执行请求
        CloseableHttpResponse response = httpClient.execute(get);
        //取响应的结果
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity, "utf-8");
        System.out.println(string);
        //关闭httpclient
        response.close();
        httpClient.close();
    }

2.带参数的get请求

@Test
    public void doGetWithParam() throws Exception{
        //建立一个httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //建立一个uri对象
        URIBuilder uriBuilder = new URIBuilder("http://www.sogou.com/web");
        uriBuilder.addParameter("query", "花千骨");
        HttpGet get = new HttpGet(uriBuilder.build());
        //执行请求
        CloseableHttpResponse response = httpClient.execute(get);
        //取响应的结果
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity, "utf-8");
        System.out.println(string);
        //关闭httpclient
        response.close();
        httpClient.close();
    }

3.post请求

@Test
    public void doPost() throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
    
        //建立一个post对象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");
        //执行post请求
        CloseableHttpResponse response = httpClient.execute(post);
        String string = EntityUtils.toString(response.getEntity());
        System.out.println(string);
        response.close();
        httpClient.close();
        
    }

4.带参数的post请求

@Test
    public void doPostWithParam() throws Exception{
        CloseableHttpClient httpClient = HttpClients.createDefault();
        
        //建立一个post对象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");
        //建立一个Entity。模拟一个表单
        List<NameValuePair> kvList = new ArrayList<>();
        kvList.add(new BasicNameValuePair("username", "zhangsan"));
        kvList.add(new BasicNameValuePair("password", "123"));
        
        //包装成一个Entity对象
        StringEntity entity = new UrlEncodedFormEntity(kvList, "utf-8");
        //设置请求的内容
        post.setEntity(entity);
        
        //执行post请求
        CloseableHttpResponse response = httpClient.execute(post);
        String string = EntityUtils.toString(response.getEntity());
        System.out.println(string);
        response.close();
        httpClient.close();
    }