Question

Is it possible to read different property groups from a Java file, without manual processing?

By “manual” I mean reading the file line by line, detecting where the start of a property group is and then extracting the corresponding key-value pairs. In practice, this means reinventing (most of) the wheel that the Properties.load() method constitutes.

Essentially, what I am looking for is an easy way of reading, from a single file, multiple groups of properties, with each group being identifiable, so that it can be loaded in its own Java Properties object.

Answer 1

I you want to use java.util.Properties you can use prefixes. In .properties file:

group1.key1=valgroup1key1
group2.key1=valgroup2key1
group2.key2=valgroup2key2

and read them like this:

class PrefixedProperty extends Properties {
    public String getProperty(String group, String key) {
        return getProperty(group + '.' + key);
    }
}

and using:

/* loading, initialization like for java.util.Properties */
String val = prefixedProperty.getProperty("group1", "key1");

You can also use ini4j with windows ini files.

Another, better way is using own, custom structured file (for example XML).