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Eric Bruno

Dr. Dobb's Bloggers

Java and Network Port Restrictions

April 03, 2014

I've recently run into issues running JavaDB or Apache Derby with the latest Java SE 1.6 and Java SE 7 updates and now with Java SE 8. The issue is related to the latest set of security enhancements made to Java via an update. In this case, the issue requires you to explicitly grant access to Derby to listen on port 1527. In fact, Oracle modified the permissions to not allow Java applications to bind to any ports outside of the ephemeral range of 49152-65535 unless you explicitly grant it. Therefore, this issue would occur for any application running with the latest JVMs that attempts to bind to a port outside of this range.

For Derby, the easiest way to allow it is to first locate the java.policy security policy file within the {JDK_HOME}/jre/lib/security directory, where {JDK_HOME} is the location you installed the JDK. Then, add the following very liberal entry (not recommended) for port 1527 to allow any Java application access to it, within the section of the file with other "grant" entries:

 
grant {
    permission java.net.SocketPermission "localhost:1527", "listen";
};
 

You can be even more liberal and allow all access via this grant entry:

 
grant {
    permission java.security.AllPermission;
};
 

A safer entry would be to limit it to JavaDB or Derby only, and then only with the access it requires, via an entry similar to this:

 
grant codeBase "file:/Applications/NetBeans/glassfish/javadb/lib/*" {
    permission java.net.SocketPermission "localhost:1527", "listen,resolve";
};

You can read more about this security enhancement here. I hope this helps.

Happy Coding!
-EJB

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