Automatically update Java on Ubuntu Linux

With the rate of updates and security patches for Java, administration of your Ubuntu machines can become tedious. There’s a better way… allow it to check for and update with your other software. The steps are easy…


sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer

NOTE: You can also install java8 in the same manner with:
sudo apt-get install oracle-java8-installer

NOTE: The Java Control Panel can sometimes be hard to locate, it will be at the following:
/usr/lib/jvm/java-7-oracle/bin/ControlPanel

REFERENCES:

java.policy file

While it’s not preferred or even ‘secure’, sometimes the need arises to ‘open’ up the Java security model.   Fortunately this is an easy task.

This is located in a file named ‘java.policy’ in the “JRE/lib/security” folder.

Default file (from JRE 1.5.0.x) resembles the following…

// Standard extensions get all permissions by default

grant codeBase “file:${{java.ext.dirs}}/*” {
permission java.security.AllPermission;
};

// default permissions granted to all domains

grant {
// Allows any thread to stop itself using the java.lang.Thread.stop()
// method that takes no argument.
// Note that this permission is granted by default only to remain
// backwards compatible.
// It is strongly recommended that you either remove this permission
// from this policy file or further restrict it to code sources
// that you specify, because Thread.stop() is potentially unsafe.
// See “http://java.sun.com/notes” for more information.
permission java.lang.RuntimePermission “stopThread”;

// allows anyone to listen on un-privileged ports
permission java.net.SocketPermission “localhost:1024-“, “listen”;

// “standard” properies that can be read by anyone

permission java.util.PropertyPermission “java.version”, “read”;
permission java.util.PropertyPermission “java.vendor”, “read”;
permission java.util.PropertyPermission “java.vendor.url”, “read”;
permission java.util.PropertyPermission “java.class.version”, “read”;
permission java.util.PropertyPermission “os.name”, “read”;
permission java.util.PropertyPermission “os.version”, “read”;
permission java.util.PropertyPermission “os.arch”, “read”;
permission java.util.PropertyPermission “file.separator”, “read”;
permission java.util.PropertyPermission “path.separator”, “read”;
permission java.util.PropertyPermission “line.separator”, “read”;

permission java.util.PropertyPermission “java.specification.version”, “read”;
permission java.util.PropertyPermission “java.specification.vendor”, “read”;
permission java.util.PropertyPermission “java.specification.name”, “read”;

permission java.util.PropertyPermission “java.vm.specification.version”, “read”;
permission java.util.PropertyPermission “java.vm.specification.vendor”, “read”;
permission java.util.PropertyPermission “java.vm.specification.name”, “read”;
permission java.util.PropertyPermission “java.vm.version”, “read”;
permission java.util.PropertyPermission “java.vm.vendor”, “read”;
permission java.util.PropertyPermission “java.vm.name”, “read”;
};

The replacement to remove all restrictions…

grant {
permission java.security.AllPermission;
};

Just be sure to restore your settings back to ‘normal’ before visiting any untrusted websites or java applications.