ResourceBundle.getBundle(String, Control) in Java

ResourceBundle.getBundle(String, Control): This method is available in java.util.ResourceBundle class of Java.

Syntax:

ResourceBundle java.util.ResourceBundle.getBundle(String baseName, Control control)

This method takes two arguments. This method returns a resource bundle using the specified base name, the default locale, and the specified control.

Parameters: Two parameters are required for this method.

baseName: the base name of the resource bundle, a fully qualified classname.

control: the control which gives information for the resource bundle loading process.

Returns: a resource bundle for the given base name and the default locale.

Throws:

1. NullPointerException - if baseName or control is null.

2. MissingResourceException - if no resource bundle for the specified base name can be found.

3. llegalArgumentException - if the given control doesn't perform properly.

4. UnsupportedOperationException - if this method is called in a named module.

Note: Please create a Hello_en_US.properties in the classpath with content

Hello = Hello Java Program

Approach 1: When no exception

Java

import java.util.ResourceBundle;
import java.util.ResourceBundle.Control;

public class ResourceBundlegetBundle2 {
    public static void main(String[] args) {

        String baseName = "Hello";
        ResourceBundle.Control control =
       ResourceBundle.Control.getControl(Control.FORMAT_DEFAULT);

        ResourceBundle bundle = 
           ResourceBundle.getBundle(baseName, control);

        System.out.println(bundle.getString(baseName));

    }
}

Output:

Hello Java Program

Approach 2: NullPointerException

Java

import java.util.ResourceBundle;
import java.util.ResourceBundle.Control;

public class ResourceBundlegetBundle2 {
    public static void main(String[] args) {

        String baseName = null;
        ResourceBundle.Control control =
       ResourceBundle.Control.getControl(Control.FORMAT_DEFAULT);

        ResourceBundle bundle = 
         ResourceBundle.getBundle(baseName, control);

        System.out.println(bundle.getString(baseName));

    }
}

Output:

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.hashCode()" because "this.name" is null
	at java.base/java.util.ResourceBundle$CacheKey.hashCode(ResourceBundle.java:744)
	at java.base/java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
	at java.base/java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1629)
	at java.base/java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1593)
	at java.base/java.util.ResourceBundle.getBundleImpl(ResourceBundle.java:1556)
	at java.base/java.util.ResourceBundle.getBundle(ResourceBundle.java:904)
	

Approach 3: MissingResourceException 

Java

import java.util.ResourceBundle;
import java.util.ResourceBundle.Control;

public class ResourceBundlegetBundle2 {
    public static void main(String[] args) {

        String baseName = "hello";
        ResourceBundle.Control control =
       ResourceBundle.Control.getControl(Control.FORMAT_DEFAULT);

        ResourceBundle bundle = 
         ResourceBundle.getBundle(baseName, control);

        System.out.println(bundle.getString(baseName));

    }
}

Output:

Exception in thread "main" java.util.MissingResourceException: Can't find resource for bundle java.util.PropertyResourceBundle, key hello
	at java.base/java.util.ResourceBundle.getObject(ResourceBundle.java:564)
	at java.base/java.util.ResourceBundle.getString(ResourceBundle.java:521)