Multiple values in java.util.Properties

Question

It seems that java.util.Properties assumes one value per propery key. That is,

foo=1 foo=2 

is not expected,

Is there a class for this kind of multi-value property sheet, which also provides the load method?

Answer 1

Try:

foo=1,2  String[] foos = properties.getProperty("foo").split(","); 

Answer 2

The java.util.Properties function is pretty limited. If you want support list, you might want try PropertyConfiguration from Apache Commons Configuration,

http://commons.apache.org/configuration/userguide/howto_properties.html#Using_PropertiesConfiguration

With it, you can set any delimiters to your list and it will split for you automatically. You can also do other fancy things in properties file. For example,

foo=item1, item2 bar=${foo}, item3 number=123 

You can retrieve it like this,

Configuration config = new PropertiesConfiguration("your.properties"); String[] items = config.getStringArray("bar"); // return {"item1", "item2", "item3"} int number = config.getInt("number", 456); // 456 is default value