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Identify yourself using HTTP AuthentificationTag(s): Networking


import java.net.*;
import java.io.*;

public class TestAuth {

  public static void main (String args[]){
    /*
    ** args[0]  is the URL protected
    ** args[1]  is the username
    ** args[2]  is the password
    */
    try {
      BufferedReader in = new BufferedReader(
          new InputStreamReader
             (openURLForInput(new URL(args[0]), args[1], args[2])));
      String line;
      while ((line = in.readLine()) != null) {
          System.out.println(line);
          }
    }
    catch (IOException e) {
      e.printStackTrace();
    }
  }

  public static InputStream openURLForInput
       (URL url, String uname, String pword)
       throws IOException
  {
    URLConnection conn = url.openConnection();
    conn.setDoInput (true);
    conn.setRequestProperty ("Authorization",
       userNamePasswordBase64(uname,pword));
    conn.connect ();
    return conn.getInputStream();
  }

  public static String userNamePasswordBase64
       (String username, String password)
  {
    return "Basic " + base64Encode (username + ":" + password);
  }

  private final static char base64Array [] = {
      'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
      'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
      'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
      'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
      'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
      'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
      'w', 'x', 'y', 'z', '0', '1', '2', '3',
      '4', '5', '6', '7', '8', '9', '+', '/'
  };



  private static String base64Encode (String string)    {
    String encodedString = "";
    byte bytes [] = string.getBytes ();
    int i = 0;
    int pad = 0;
    while (i < bytes.length) {
      byte b1 = bytes [i++];
      byte b2;
      byte b3;
      if (i >= bytes.length) {
         b2 = 0;
         b3 = 0;
         pad = 2;
         }
      else {
         b2 = bytes [i++];
         if (i >= bytes.length) {
            b3 = 0;
            pad = 1;
            }
         else
            b3 = bytes [i++];
         }
      byte c1 = (byte)(b1 >> 2);
      byte c2 = (byte)(((b1 & 0x3) << 4) | (b2 >> 4));
      byte c3 = (byte)(((b2 & 0xf) << 2) | (b3 >> 6));
      byte c4 = (byte)(b3 & 0x3f);
      encodedString += base64Array [c1];
      encodedString += base64Array [c2];
      switch (pad) {
       case 0:
         encodedString += base64Array [c3];
         encodedString += base64Array [c4];
         break;
       case 1:
         encodedString += base64Array [c3];
         encodedString += "=";
         break;
       case 2:
         encodedString += "==";
         break;
       }
      }
      return encodedString;
  }
}

A better alternative is the Authenticator class, see this HowTo.


NOTE: a simple explanation about the base64 encoding principle is shown in this How-to.

An alternative way to Base64 encoding is to use the Base64 class in the sun.misc.* package.

sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
String encodedUserPwd =
  encoder.encode("domain\\username:password".getBytes());
con.setRequestProperty("Proxy-Authorization", "Basic " + encodedUserPwd);
Use of the sun.* package is "discouraged" by sun and not formally supported. Those classes can be missing in your JDK release.

Check this HowTo for a more official way to encode/decode to/from Base64.


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