Program: How to assign default values for unavailable keys in properties file?

The Properties class also provide a method, incase if the key is not available in the properties file, then you can specify the default value. Below example give sample code for this.

package com.java2novice.properties;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class MyPropDefaultValue {

private Properties prop = null;
	
	public MyPropDefaultValue(){
		
		InputStream is = null;
		try {
			this.prop = new Properties();
			is = this.getClass().getResourceAsStream("/sample.properties");
			prop.load(is);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public String getPropertyValue(String key){
		return this.prop.getProperty(key, "Its Default Value");
	}
	
	public static void main(String a[]){
		
		MyPropDefaultValue mpc = new MyPropDefaultValue();
		System.out.println("db.host: "+mpc.getPropertyValue("db.tables"));
		System.out.println("db.user: "+mpc.getPropertyValue("db.user"));
	}
}

db.host=appdomain.java2novice.com
db.user=java2novice
db.password=mypassword
db.service=orcl

db.host: Its Default Value
db.user: java2novice