How to use java.util.Properties to store config parameters in an external file.

config.txt

#sample config file
secret=ThisIsMySecret
secretNumber=111

UConfigFile.pde

/*

  Marius Watz, April 2014
  http://workshop.evolutionzone.com
  
  How to load a config file using the java.util.Properties class.
  Useful for sketches that require login/password or API secrets. 
  
*/

import java.util.*;
import java.io.FileInputStream;

HashMap<String, String> conf;
String filename="config.txt";

void setup() {
  conf=confRead(filename);

  // print all keys and values
  println("Config: "+filename+" ("+conf.keySet().size()+" keys)");
  println("---------------");
  
  for (String s:conf.keySet()) {
    println("\tkey: '"+s+"' = '"+confGet(s)+"'");
  }
  println("---------------\n");
  
  println(confGet("NoSuchKey"));
}

String confGet(String key) {
  if(conf.containsKey(key)) return conf.get(key);
  
  println("'"+key+"' not found");
  return null;
}

HashMap<String, String> confRead(String filename) {
  HashMap<String, String> map=new HashMap<String, String>();
  Properties config;

  try {
    config=new Properties();
    config.load(new FileInputStream(sketchPath(filename )));
    Enumeration<String> keys=(Enumeration<String>)config.propertyNames();

    while (keys.hasMoreElements ()) {
      String s=keys.nextElement();
      map.put(s, config.getProperty(s));
    }
  } 
  catch(Exception e) {
    e.printStackTrace();
  }

  return map;
}


void draw() {
  exit();
}