Unable to start derby database from Netbeans 7.4

Question

I downloaded Netbeans 7.4 and Java 7 Update 51. I get the below error when I try to start Java DB or derby connection from Netbeans. This is on a windows 8 PC. I downloaded

Answer 1

This is what I did:

1. Find out exactly where the java home is by executing this instruction from NetBeans 7.4 :

   System.out.println(System.getProperty("java.home"));

   This is the output for my case:

   C:\Program Files\Java\jdk1.7.0_51\jre

   which is quite important for me, I was modifying another java.policy and took no effect and wasted me a couple of hours.

2. For reason of java.policy is an unix style file and read-only, I opened and edited it with notepad++ and executed as administrator (under the same java home):

   C:\Program Files\Java\jdk1.7.0_51\jre\lib\security\java.policy

   Add only these lines into the file after the first grant:

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

3. Save the file, which is a little tricky for reason of the permission. But if you run notepad++ or any other edit program as administrator, you can solve the problem.
   
   Then try to connect the database from NetBeans, it works for me.

Good luck.