ChoiceFormat applyPattern() method in Java with Examples

The java.text.ChoiceFormat is a class containing an applyPattern() as a function. Using the ChoiceFormat class, the current limit and format can be overridden to set the new pattern text for the ChoiceFormat. The combination of the ChoiceFormat format and limit will be this new pattern.

Syntax:

Parameter: The new text pattern for ChoiceFormat is called newPattern, and it is the parameter for the above method.

Return Value: No value is returned by implementing this method

Exception: In the case that the given newPattern is null, this function raises a NullPointerException.

Example 1:

The Java program that is included demonstrates the way to convert numerical limits to particular string values using the ChoiceFormat class. First of all, it generates a ChoiceFormat object with six number limits, one for each month from January to June. The program then prints the ChoiceFormat object's current pattern. After that, it maps numbers from 7 to 12 to the months of July through December by applying a new pattern using the applyPattern() function. Lastly, the updated pattern with the modified mappings is printed.

Implementation:

FileName: ChoiceFormatApplyPatternExample1.java

import java.text.*;
import java.util.*;
import java.io.*;
public class ChoiceFormatApplyPatternExample1 
{
	public static void main(String[] argv)
	{
		// Initializing and creating the limits
		double[] limit = { 1, 2, 3, 4, 5, 6 };
		// Initializing and creating the formats
		String[] format = { "JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE" };
		// Initializing and creating the choiceformat
		ChoiceFormat chofor	= new ChoiceFormat(limit, format);
		System.out.println("The current ChoiceFormat pattern : " + chofor.toPattern());
		// applying the updated pattern and utilizing 
		// the apply pattern() function
		chofor.applyPattern("7#JULY| 8#AUGUST | 9#SEPTEMBER | 10#OCTOBER | 11#NOVEMBER | 12#DECEMBER");
		System.out.println("\nThe new ChoiceFormat pattern : " + chofor.toPattern());
	}
}

Output:

The current ChoiceFormat pattern : 1.0#JANUARY|2.0#FEBRUARY|3.0#MARCH|4.0#APRIL|5.0#MAY|6.0#JUNE
The new ChoiceFormat pattern : 7.0#JULY|8.0#AUGUST |9.0#SEPTEMBER |10.0#OCTOBER |11.0#NOVEMBER |12.0#DECEMBER

Example 2:

The Java program given shows how to handle a NullPointerException when utilizing the ChoiceFormat class's applyPattern() function. It first creates a ChoiceFormat object and prints the current pattern, setting boundaries from 1 to 6, which represent the months of January through June. It then throws a NullPointerException when attempting to apply a null pattern. When the application detects this exception, it displays the relevant error message and a description of the issue.

Implementation:

FileName: ChoiceFormatApplyPatternExample2.java

import java.text.*;
import java.util.*;
import java.io.*;
public class ChoiceFormatApplyPatternExample2
{
	public static void main(String[] argv)
	{
	    try
	    {
	        // Initializing and creating the limits
		    double[] limit = { 1, 2, 3, 4, 5, 6 };
		    // Initializing and creating the formats
		    String[] format = { "JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE" };
		    // Initializing and creating the choiceformat
		    ChoiceFormat chofor	= new ChoiceFormat(limit, format);
		    System.out.println("The current ChoiceFormat pattern : " + chofor.toPattern());
		    // applying the updated pattern and utilizing 
		    // the apply pattern() function
		    chofor.applyPattern(null);
		    System.out.println("\nThe new ChoiceFormat pattern : " + chofor.toPattern());   
	    }
	    catch (NullPointerException ex) 
	    {
			System.out.println("\n The String is Null");
			System.out.println("The Exception thrown is : " + ex);
		}
	}
}

Output:

The current ChoiceFormat pattern : 1.0#JANUARY|2.0#FEBRUARY|3.0#MARCH|4.0#APRIL|5.0#MAY|6.0#JUNE
The String is Null
The Exception thrown is : java.lang.NullPointerException: Cannot invoke "String.length()" because "newPattern" is null

Next TopicChoiceformat-format-method-in-java-with-examples

← prev next →