java.util.Properties may be what you need.

You need Java's I/O functionality.  There are a number
of ways (using different classes) you can use.
Check here for a good overview.
<http://java.sun.com/docs/books/tutorial/essential/io/>

.... The following answer is what I put when I thought
you were talking about user program preferences specifically.
It might (or might not) better answer your question.

There are a variety of classes that might be of help.

Is this an application?  (unstrusted Applets have security restrictions.)

The easiest is possibly the Preferences[1] class, which
is a Java 1.4+ class to store/retrieve preferences.  
I have not had cause to use the preferences API as yet.

[1]
<http://java.sun.com/j2se/1.5.0/docs/api/java/util/prefs/Preferences.html>

There are also other ways to store program preferences.

You can create a custom class that stores the relevant attributes,
then use object serialisation[2] to write it to disk and retrieve it.
If your custom class is also a bean, you can use the
XMLDecoder/Encoder[3] classes introduced in 1.4.

[2] <http://java.sun.com/j2se/1.5.0/docs/guide/serialization/>

[3]
<http://java.sun.com/j2se/1.5.0/docs/api/java/beans/XMLDecoder.html>
<http://java.sun.com/j2se/1.5.0/docs/api/java/beans/XMLEncoder.html>

HTH

Look at the  java.util.prefs  package.

Examples at http://javaalmanac.com/egs/java.util.prefs/pkg.html

Bye.