How to Get All Keys From Properties File in Java

In this example we will show how to get all keys from properties file.

Source Code

package com.beginner.examples;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import java.util.Set;

public class GetAllKeysFromPropertiesFile {

	public static void main(String[] args) {
		
		try {
			Properties properties = new Properties();
			File file = new File("tmp.properties");
			InputStream inputStream = new FileInputStream(file);
			properties.load(inputStream);
			
			/*
			 * Use the method keySet() which will be returned in the form of set object.
			 */
			Set set = properties.keySet();
			for(Object key : set) {
				String keyString = key.toString();
				System.out.println(keyString);
			}
			
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException ioException) {
			ioException.printStackTrace();
		}

	}

}

tmp.properties:

db.username = Alice
db.userage = 17

Output:

db.username
db.userage

References

Imported packages in Java documentation: