Java examples on commons.lang

• How do I find specific elements in an array?
• How do I check for an empty string?
• How do I convert array of object to array of primitive?
• How do I reverse array elements order?
• How do I convert an array to a Map?
• How do I reverse a string, words or sentences?
• How do I check if a string is empty or not?
• How do I count word occurrences in a string?
• How do I use Apache Commons ToStringBuilder?
• How do I find text between two strings?
• How do I get the nearest hour, minute, second of a date?
• How do I format date and time using DateFormatUtils class?
• How do I use ReflectionToStringBuilder class?
• How do I generate a random alpha-numeric string?
• How do I use CompareToBuilder class?
• How do I convert array of primitives into array of objects?
• How do I implement equals method using commons-lang?
• How do I implement hashCode using commons-lang?
• How do I capitalize each word in a string?
• How do I checks if two dates are on the same day?

How do I convert array of object to array of primitive?

In the code example below we demonstrate the ArrayUtils.toPrimitive() method to convert an array of Integer object to an array of its primitive type. Besides converting array of Integer objects this method is overloadded to accept other types of object array.

package org.kodejava.example.commons.lang;

import org.apache.commons.lang.ArrayUtils;

public class ObjectArrayToPrimitiveDemo {

    public static void main(String[] args) {
        //
        // An array of integer objects.
        //
        Integer[] integers = {new Integer(1), new Integer(2), new Integer(3),
                              new Integer(5), new Integer(8), new Integer(13),
                              new Integer(21), new Integer(34), new Integer(55)};

        //
        // Convert array of integer objects to a primitive array of type int
        //
        int[] fibbos = ArrayUtils.toPrimitive(integers);
        System.out.println(ArrayUtils.toString(fibbos));
    }
}