Name: dbT83986 Date: 02/27/99


Passing InetAddress.getByName() an IP address of a Multicast
host (i.e. 224.0.1.25 - NBC-PRO.MCAST.NET) returns an InetAddress
object with the host name field the same as the IP address in
JDK2. There was a bug fix in 1.1 that addressed this problem,
but apparently something in JDK2 broke it for multicast addresses,
as getByName() works in JDK1.1.7B even if the IP address is
a multicast host. Run the following code and supply 224.0.1.25
as the command line arg under 1.2 and 1.1.7:

  import java.net.*;

class getNameByIP {

public static void main (String args[]) {

    String s = null;
    InetAddress address = null;

    if (args.length > 0) {
      try {
        s = args[0];
        address = InetAddress.getByName(s);
        System.out.println(address);
      }
      catch (UnknownHostException e) {
        System.err.println(e);
      }
    }
    else {
      System.out.println("USAGE: java getNameByIP XX.XX.XX.XX");
    }
  }
}

Here is the output from JDK1.2:

c:\jdk1.2\bin\java.exe getNameByIP 224.0.1.25
Working Directory - C:\NICKPRGS\JAVA\netprog\chap13Class Path - c:\nickprgs\java\brazziel\;.;C:\Program Files\Kawa\classes.zip;c:\jdk1.2\lib\tools.jar;c:\jdk1.2\jre\lib\rt.jar
224.0.1.25/224.0.1.25



Here is the output from JDK1.1.7B:

c:\jdk1.1.7B\bin\java.exe getNameByIP 224.0.1.25
Working Directory - C:\NICKPRGS\JAVA\netprog\chap13Class Path - c:\nickprgs\java\brazziel\;.;C:\Program Files\Kawa\classes.zip;c:\jdk1.1.7b\lib\classes.zip
NBC-PRO.MCAST.NET/224.0.1.25

Process Exit...
(Review ID: 52276)
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