Getting a key List from Properties : Properties « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. Properties

propertyNames() method in Properties class combines the keys in the properties list with the keys in the defaults properties list passed into the constructor.

import java.io.FileInputStream;
import java.util.Enumeration;
import java.util.Properties;

public class MainClass {
  public static void main(String args[]) throws Exception {
    Properties p = new Properties();
    p.load(new FileInputStream("test.txt"));
    Enumeration e = p.propertyNames();

    for (; e.hasMoreElements();) {
      System.out.println(e.nextElement());

    }
  }
}


//File: test.txt
/*
foo:bar
one
two
three=four
five  six seven eight
nine ten


*/

five
two
one
three
nine
foo