HttpClient中的各類請求

一:什麼是HttpClient？

主要是模擬瀏覽器發送請求給server，監聽響應信息，推斷返回結果的正確性怎樣，由於避開的瀏覽器的UI 
，也就將瀏覽器中所有載入的時間（比方經常要載入圖片啊）都省掉了，因此這個運行效率至關高

二. 使用HttpClient

1.get請求

@Test
    public void doGet() throws Exception {
        //建立一個httpclient對象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //建立一個GET對象
        HttpGet get = new HttpGet("http://www.sogou.com");
        //執行請求
        CloseableHttpResponse response = httpClient.execute(get);
        //取響應的結果
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity, "utf-8");
        System.out.println(string);
        //關閉httpclient
        response.close();
        httpClient.close();
    }

2.帶參數的get請求

@Test
    public void doGetWithParam() throws Exception{
        //建立一個httpclient對象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //建立一個uri對象
        URIBuilder uriBuilder = new URIBuilder("http://www.sogou.com/web");
        uriBuilder.addParameter("query", "花千骨");
        HttpGet get = new HttpGet(uriBuilder.build());
        //執行請求
        CloseableHttpResponse response = httpClient.execute(get);
        //取響應的結果
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println(statusCode);
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity, "utf-8");
        System.out.println(string);
        //關閉httpclient
        response.close();
        httpClient.close();
    }

3.post請求

@Test
    public void doPost() throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
    
        //建立一個post對象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");
        //執行post請求
        CloseableHttpResponse response = httpClient.execute(post);
        String string = EntityUtils.toString(response.getEntity());
        System.out.println(string);
        response.close();
        httpClient.close();
        
    }

4.帶參數的post請求

@Test
    public void doPostWithParam() throws Exception{
        CloseableHttpClient httpClient = HttpClients.createDefault();
        
        //建立一個post對象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");
        //建立一個Entity。模擬一個表單
        List<NameValuePair> kvList = new ArrayList<>();
        kvList.add(new BasicNameValuePair("username", "zhangsan"));
        kvList.add(new BasicNameValuePair("password", "123"));
        
        //包裝成一個Entity對象
        StringEntity entity = new UrlEncodedFormEntity(kvList, "utf-8");
        //設置請求的內容
        post.setEntity(entity);
        
        //執行post請求
        CloseableHttpResponse response = httpClient.execute(post);
        String string = EntityUtils.toString(response.getEntity());
        System.out.println(string);
        response.close();
        httpClient.close();
    }