How can I write Java properties in a defined order?

Question

I'm using java.util.Properties's store(Writer, String) method to store the properties. In the resulting text file, the properties are stored in a haphazard order.

This is what I'm doing:

Properties properties = createProperties(); properties.store(new FileWriter(file), null); 

How can I ensure the properties are written out in alphabetical order, or in the order the properties were added?

I'm hoping for a solution simpler than "manually create the properties file".

Answer 1

As per "The New Idiot's" suggestion, this stores in alphabetical key order.

Properties tmp = new Properties() {     @Override     public synchronized Enumeration<Object> keys() {         return Collections.enumeration(new TreeSet<Object>(super.keySet()));     } }; tmp.putAll(properties); tmp.store(new FileWriter(file), null); 

Answer 2

See https://github.com/etiennestuder/java-ordered-properties for a complete implementation that allows to read/write properties files in a well-defined order.

OrderedProperties properties = new OrderedProperties(); properties.load(new FileInputStream(new File("~/some.properties")));