{{category プログラミング}}
{{category Java}}

!GETメソッド
HTTPコネクションをはって，データを取得する．
 import java.net.URL;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.ProtocolException;
 import java.io.*;
 
 public class HttpGetTest {
 
   public HttpURLConnection connection;
   private String newline = System.getProperty("line.separator");
 
   public HttpGetTest(String url){
 
     try{
       URL u = new URL(url);
       connection = (HttpURLConnection)u.openConnection();
       connection.setRequestMethod("GET");
       HttpURLConnection.setFollowRedirects(false);
       connection.setInstanceFollowRedirects(false);
     }catch(MalformedURLException e){
       e.printStackTrace();
     } catch (ProtocolException e1) {
       e1.printStackTrace();
     } catch (IOException e) {
       e.printStackTrace();
     }
   }
 
   /**
    * 接続し，ウェブサイトからのレスポンスを読み込む
    */
   public void read(OutputStream out){
     try {
       connection.connect();
     } catch (IOException e) {
       e.printStackTrace();
     }
     try {
       byte[] buf = new byte[1024];
       int length = connection.getContentLength();
       DataInputStream in = new DataInputStream(connection.getInputStream());
       int len = 0;
       int sum = 0;
       System.out.println("length: " + length);
       System.out.print(" *");
       while((len = in.read(buf)) > 0){
 	sum += len;
 	if(sum > length/10){
 	  System.out.print("*");
 	  sum = 0;
 	}
 	out.write(buf, 0, len);
       }
     } catch (IOException e) {
       e.printStackTrace();
     }
     connection.disconnect();
   }
 
   public static void main(String[] args) throws Exception{
     HttpGetTest http = new HttpGetTest(args[0]);
     StringWriter out = new StringWriter();
     String path = http.connection.getURL().getFile();
     int index = path.lastIndexOf('/');
     String file = path.substring(index+1);
     if(file.equals("")) file = "default.out";
     System.out.println("output => " + file);
     System.out.print(" ");
     http.read(new FileOutputStream(file));
     System.out.println();
     //System.out.println(http.connection.getContentType());
     //System.out.println(http.connection.getContentEncoding());
     //System.out.println(out);
   }
 }