绑定到同一端口时，java ServerSocket不会引发IOException

Question

I have an issue with my code as follow. code:

int port = 14205; // begin port
// Try to bind socket on any port<br>

while(true){

try {
     InetSocketAddress isa = new InetSocketAddress(port);
    Log.logFile("bind port = " + port);

        // ss is a ServerSocket object
    ss.bind( isa );

    break;
} catch (IOException e) {
    Log.logFile("exception");
    port++;
}
 }

I ran this code on JVM 1.7 and JVM 1.6 at the same time on the same machine (win7x64). using CurrPorts tool to investigate what port we are listening. result: we'are listening on the same port 14207. I think JVM must throw an IOException when run 2nd instance of this code but it didn't.

what wrong with my code? please help. note: I must run in this senario (2 JVMs).

Answer 1

break; will break your while loop and exit from the while loop and no question about catching exception . However, When your are trying to catch the exception you need to print exception message to log file.

replace this

Log.logFile("exception");

with this

Log.logFile("exception"+ e.toString());

Answer 2

第一次绑定后，循环中断。

Answer 3

ok! I will answer my question. this is JVM bug. for more information please refer to Oracle bugbase: http://bugs.sun.com/bugdatabase/view_bug.do;jsessionid=71f70e71266a551ce53dcda4a050c?bug_id=7174699