HttpClient use process

 manual

• Creating  HttpClient Objects
• Request method creates an instance, and specify the requested URL. If you need to send a GET request to create  HttpGet an object; if you need to send a POST request to create  HttpPost an object.
• To send the request parameters, it can be called  HttpGet, HttpPost a common  setParams(HttpParams params) way to add a request parameter; for  HttpPost purposes of object can call  setEntity(HttpEntity entity) the method set request parameters.
• Calling  HttpClient object  execute(HttpUriRequest request) sends a request, the method returns a  HttpResponse.
• Calling  HttpResponse of  getAllHeaders(), getHeaders(String name) or the like can be obtained in response to the first server; call  HttpResponse the  getEntity() method obtains  HttpEntity object content server in response to the package. Program available through the content server in response to the object.
• Release the connection. Whether the implementation of the method is successful, the connection must be released

 

Case

• pom.xml Configuration is as follows:

  <!-- Apache Http Begin -->
  <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpclient</artifactId>
      <version>4.5.5</version>
  </dependency>
  <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>fluent-hc</artifactId>
      <version>4.5.5</version>
  </dependency>
  <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpmime</artifactId>
      <version>4.5.5</version>
  </dependency>
  <!-- Apache Http End -->

   

• Creating HttpGet request

  package com.funtl.hello.httpclient;
  
  import org.apache.http.HttpEntity;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.impl.client.CloseableHttpClient;
  import org.apache.http.impl.client.HttpClients;
  import org.apache.http.util.EntityUtils;
  
  import java.io.IOException;
  
  public class MyTest {
      public static void main(String[] args) {
          get();
      }
  
      private static void get() {
          // 创建 HttpClient 客户端
          CloseableHttpClient httpClient = HttpClients.createDefault();
  
          // 创建 HttpGet 请求
          HttpGet httpGet = new HttpGet("http://localhost:8080/content/page?draw=1&start=0&length=10");
          // 设置长连接
          httpGet.setHeader("Connection", "keep-alive");
          // 设置代理（模拟浏览器版本）
          httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36");
          // 设置 Cookie
          httpGet.setHeader("Cookie", "UM_distinctid=16442706a09352-0376059833914f-3c604504-1fa400-16442706a0b345; CNZZDATA1262458286=1603637673-1530123020-%7C1530123020; JSESSIONID=805587506F1594AE02DC45845A7216A4");
  
          CloseableHttpResponse httpResponse = null;
          try {
              // 请求并获得响应结果
              httpResponse = httpClient.execute(httpGet);
              HttpEntity httpEntity = httpResponse.getEntity();
              // 输出请求结果
              System.out.println(EntityUtils.toString(httpEntity));
          } catch (IOException e) {
              e.printStackTrace();
          }
  
          // 无论如何必须关闭连接
          finally {
              if (httpResponse != null) {
                  try {
                      httpResponse.close();
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
  
              if (httpClient != null) {
                  try {
                      httpClient.close();
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
          }
      }
  }

   

• Creating HttpPost request

  package com.funtl.hello.httpclient;
  
  import org.apache.http.HttpEntity;
  import org.apache.http.client.ClientProtocolException;
  import org.apache.http.client.entity.UrlEncodedFormEntity;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.impl.client.CloseableHttpClient;
  import org.apache.http.impl.client.HttpClients;
  import org.apache.http.message.BasicNameValuePair;
  import org.apache.http.util.EntityUtils;
  
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.util.ArrayList;
  import java.util.List;
  
  public class MyTest {
      public static void main(String[] args) {
          post();
      }
  
      private static void post() {
          // 创建 HttpClient 客户端
          CloseableHttpClient httpClient = HttpClients.createDefault();
  
          // 创建 HttpPost 请求
          HttpPost httpPost = new HttpPost("http://localhost:8080/content/page");
          // 设置长连接
          httpPost.setHeader("Connection", "keep-alive");
          // 设置代理（模拟浏览器版本）
          httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36");
          // 设置 Cookie
          httpPost.setHeader("Cookie", "UM_distinctid=16442706a09352-0376059833914f-3c604504-1fa400-16442706a0b345; CNZZDATA1262458286=1603637673-1530123020-%7C1530123020; JSESSIONID=805587506F1594AE02DC45845A7216A4");
  
          // 创建 HttpPost 参数
          List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();
          params.add(new BasicNameValuePair("draw", "1"));
          params.add(new BasicNameValuePair("start", "0"));
          params.add(new BasicNameValuePair("length", "10"));
  
          CloseableHttpResponse httpResponse = null;
          try {
              // 设置 HttpPost 参数
              httpPost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));
              httpResponse = httpClient.execute(httpPost);
              HttpEntity httpEntity = httpResponse.getEntity();
              // 输出请求结果
              System.out.println(EntityUtils.toString(httpEntity));
          } catch (UnsupportedEncodingException e) {
              e.printStackTrace();
          } catch (ClientProtocolException e) {
              e.printStackTrace();
          } catch (IOException e) {
              e.printStackTrace();
          }
  
          // 无论如何必须关闭连接
          finally {
              try {
                  if (httpResponse != null) {
                      httpResponse.close();
                  }
              } catch (IOException e) {
                  e.printStackTrace();
              }
  
              try {
                  if (httpClient != null) {
                      httpClient.close();
                  }
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
      }
  }