Question

I just recently learned about the Properties class in java, and I’m trying to translate my old configuration file to be compatible with the Properties class. I want to know what would be the best way to setup a properties file for something like this:

Object type1
name obj1
age age1

Object type2
name obj2
age age2

I used spaces because I was using a Scanner to parse the file. I would create a List of Objects that stored the different objects and each Object had certain parameters with them, which I would get from the config file. So as I read along the file I would get the properties and create the object and store into my List.

I don’t want to use XML to create my properties file. I want something simple for a user to create and something that I could read easily in Java.

Any suggestions?

EDIT:
I want to try to get something with no need of numbering. For example in XML you can do something like this:

<table>
   <fields>
      <field>
         <type>type1</type>
      </field>
      <field>
         <type>type2</type>
      <field>
   </fields>
</table>

Obviously it would be easier to make a XML file like this, but I want to implement in a non-XML way.

Answer 1

The property keys ought to be unique. I’d suggest to use a numerical infix.

field1.type = type1
field1.name = obj1
field1.age = age1

field2.type = type2
field2.name = obj2
field2.age = age2

Then you can gather them in an incremental loop as follows:

Properties properties = new Properties();
properties.load(input);
List<Field> fields = new ArrayList<Field>();

for (int i = 1; i < Integer.MAX_VALUE; i++) {
    String type = properties.getProperty("field" + i + ".type");
    if (type == null) break;
    String name = properties.getProperty("field" + i + ".name");
    String age = properties.getProperty("field" + i + ".age");
    fields.add(new Field(type, name, age));
}        

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Unrelated to the concrete problem, I am confident that XML is way much easier to maintain and parse, for example with JAXB.