Http（get，post）及HttpClient（get，post）的简单使用

1. 使用 Http 的 Get 方式读取网络数据

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;

 public class TestHttpGet {

     public static void main(String[] args) {
         new ReadByGet().start();
     }
     static class ReadByGet extends Thread{
         @Override
         public void run() {
             try {
                 URL url = new URL("http://fanyi.youdao.com/openapi.do?keyfrom=jkxyuvi&key=1530995034&type=data&doctype=xml&version=1.1&q=welcom");
                 URLConnection connection = url.openConnection();
                 InputStream is = connection.getInputStream();
                 InputStreamReader isr = new InputStreamReader(is);
                 BufferedReader br = new BufferedReader(isr);

                 String line;
                 StringBuilder builder = new StringBuilder();

                 while((line = br.readLine())!=null){
                     builder.append(line);

                 }
                 br.close();
                 isr.close();
                 is.close();

                 System.out.println(builder.toString());

             } catch (MalformedURLException e) {

                 e.printStackTrace();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

 }

2. 使用 Http 的 Post 方式与网络交互通信

 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;

 public class TestHttpPost {

     public static void main(String[] args) {
         new ReadByPost().start();
     }

 }
 class ReadByPost extends Thread{
     @Override
     public void run() {
         try {
             URL url = new URL("http://fanyi.youdao.com/openapi.do");
             HttpURLConnection connection = (HttpURLConnection) url.openConnection();
             connection.addRequestProperty("encoding", "UTF-8");
             connection.setDoInput(true);
             connection.setDoOutput(true);
             connection.setRequestMethod("POST");

             OutputStream os = connection.getOutputStream();
             OutputStreamWriter osw = new OutputStreamWriter(os);
             BufferedWriter bw = new BufferedWriter(osw);

             bw.write("keyfrom=jkxyuvi&key=1530995034&type=data&doctype=xml&version=1.1&q=welcome");
             bw.flush();//强制输出

             InputStream is = connection.getInputStream();
             InputStreamReader isr = new InputStreamReader(is);
             BufferedReader br = new BufferedReader(isr);
             String line;
             StringBuilder builder = new StringBuilder();
             while((line = br.readLine())!=null){
                 builder.append(line);
             }

             bw.close();
             osw.close();
             os.close();
             br.close();
             isr.close();
             is.close();
             System.out.println(builder.toString());

         } catch (MalformedURLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
 }

3. 使用HttpClient进行Get方式通信

先下载HttpClient相关依赖包，地址： http://hc.apache.org/downloads.cgi

 import java.io.IOException;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.util.EntityUtils;

 public class TestHttpClientGet {

     public static void main(String[] args) {
         new Get().start();
     }

 }
 class Get extends Thread{

     HttpClient client = HttpClients.createDefault();

     @Override
     public void run() {

         HttpGet get = new HttpGet("http://www.bai.com");
         try {
             HttpResponse response = client.execute(get);
             HttpEntity entity = response.getEntity();
             String result  =  EntityUtils.toString(entity,"UTF-8");
             System.out.println(result);
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }

     }
 }

4. 使用 HttpClient 进行 Post 方式通信

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.util.EntityUtils;

 public class TestHttpClientPost {

     public static void main(String[] args) {
         new Post().start();
     }

 }
 class Post extends Thread{

     HttpClient client = HttpClients.createDefault();

     @Override
     public void run() {
         HttpPost post = new HttpPost("http://fanyi.youdao.com/openapi.do");

         try {
             List<BasicNameValuePair> parameters = new ArrayList<>();
             parameters.add(new BasicNameValuePair("keyfrom", "jkxyuvi"));
             parameters.add(new BasicNameValuePair("key", ""));
             parameters.add(new BasicNameValuePair("type", "data"));
             parameters.add(new BasicNameValuePair("doctype", "xml"));
             parameters.add(new BasicNameValuePair("version", "1.1"));
             parameters.add(new BasicNameValuePair("q", "welcome"));
             post.setEntity(new UrlEncodedFormEntity(parameters,"UTF-8"));

             HttpResponse response = client.execute(post);
             HttpEntity entity = response.getEntity();
             String result = EntityUtils.toString(entity,"UTF-8");
             System.out.println(result);

         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }

     }
 }

与java自带的http通信，HttpClient用起来确实方便的多。