Java ResourceBundle keySet() Method

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Description

The java ResourceBundle keySet() method returns a Set of all keys contained in this ResourceBundle and its parent bundles.

Declaration

Following is the declaration for java.util.ResourceBundle.keySet() method

public Set<String> keySet()

Parameters

NA

Return Value

This method returns a Set of all keys contained in this ResourceBundle and its parent bundles.

Exception

NA

Getting Set of Keys from a Properties File of US Locale

The following example shows the usage of Java ResourceBundle keySet() method to print a set of keys present in the properties file. We've created a resource bundle of US Locale for the corresponding hello_en_US.properties file. Then we printed the text assigned to key hello. Then the set of keys is retrieved using keySet() method and is printed.

package com.tutorialspoint;

import java.util.Locale;
import java.util.ResourceBundle;

public class ResourceBundleDemo {
   public static void main(String[] args) {

      // create a new ResourceBundle with specified locale
      ResourceBundle bundle = ResourceBundle.getBundle("hello", Locale.US);

      // print the text assigned to key "hello"
      System.out.println(bundle.getString("hello"));

      // get the keys
      System.out.println(bundle.keySet());
   }
}

Output

Assuming we have a resource file hello_en_US.properties available in your CLASSPATH, with the following content. This file will be used as an input for our example program −

hello = Hello World!
bye = Goodbye World!
morning = Good Morning World!

Let us compile and run the above program, this will produce the following result −

Hello World!
[hello, bye, morning]

Getting Set of Keys from a Properties File of FRANCE Locale

The following example shows the usage of Java ResourceBundle keySet() method to print a set of keys present in the properties file. We've created a resource bundle of French Locale for the corresponding hello_fr_FR.properties file. Then we printed the text assigned to key hello. Then the set of keys is retrieved using keySet() method and is printed.

package com.tutorialspoint;

import java.util.Locale;
import java.util.ResourceBundle;

public class ResourceBundleDemo {
   public static void main(String[] args) {

      // create a new ResourceBundle with specified locale
      ResourceBundle bundle = ResourceBundle.getBundle("hello", Locale.FRANCE);

      // print the text assigned to key "hello"
      System.out.println(bundle.getString("hello"));

      // get the keys
      System.out.println(bundle.keySet());
   }
}

Output

Assuming we have a resource file hello_fr_FR.properties available in your CLASSPATH, with the following content. This file will be used as an input for our example program −

hello = Bonjour le monde!
bye = Au revoir le monde!
morning = Bonjour le monde!

Let us compile and run the above program, this will produce the following result −

Bonjour le monde!
[hello, bye, morning]

Getting Set of Keys from a Properties File of GERMAN Locale

The following example shows the usage of Java ResourceBundle keySet() method to print a set of keys present in the properties file. We've created a resource bundle of German Locale for the corresponding hello_de_DE.properties file. Then we printed the text assigned to key hello. Then the set of keys is retrieved using keySet() method and is printed.

package com.tutorialspoint;

import java.util.Locale;
import java.util.ResourceBundle;

public class ResourceBundleDemo {
   public static void main(String[] args) {

      // create a new ResourceBundle with specified locale
      ResourceBundle bundle = ResourceBundle.getBundle("hello", Locale.GERMAN);

      // print the text assigned to key "hello"
      System.out.println(bundle.getString("hello"));

      // get the keys
      System.out.println(bundle.keySet());
   }
}

Output

Assuming we have a resource file hello_de_DE.properties available in your CLASSPATH, with the following content. This file will be used as an input for our example program −

hello = Hallo Welt!
bye = Auf Wiedersehen Welt!
morning = Guten Morgen Welt!

Let us compile and run the above program, this will produce the following result −

Hello World!
[hello, bye, morning]