Quick Start How To

Quick Start How-to (Howto) for making changes to java.policy file on OS X

Termlet Home

Here is an 'QuickStart How-to' for making changes to the java.policy file that controls the security settings of Java applets on OS X. This is how-to is designed for use with the SerialPort product.

For very good reason, the default OS X configuration does not allow changes to the java.policy file. Proper changes to this file however, open up an exciting number of options and additional functionality.

This how to assumes you are using an account on OS X with admin privileges.

OS X stores the java.policy in this folder


Without proper security changes, any attempt to change the java.policy file will result in the following (or a similar) dialog.

The first step to allow changes to java.policy on OS X, is to change allow changes to the folder (directory) where that file is stored. Use finder to navigate to the folder


Ctrl-Click on the security and select "Get Info" to display the "security info" dialog, then expand the "Ownership & Permissions" to so the dialog appears as follows.

Click on the lock icon to so that it changes to unlocked to allow changes to the folder. After unlocking click "Owner", choose your user name - the 'user name (Me)'. Enter the proper password or passphrase.

The dialog should then appear as follows (user name is daveb in this example).

You can now lock the changes by clicking click the lock icon. This will require authentication for future Owner changes.

Note it is not required to click "Apply to enclosed items...". Doing so will show this dialog.

This will make the selected changed to all files and directories in the security folder. Undoing this would involve knowing all initial the file/folder settings, and applying them one-by-one.

Now, to run Termlet download the java.policy file

OS X. Ctrl-Click this link java.policy and select "Download Link to Disk". This will download the java.policy file to the OS X desktop. You can then drag the file to the folder


Note: The browser must be completely restarted before changes to the java.policy file will take affect.

Termlet Home