Java Tutorial/Apache Common/ObjectUtils

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ObjectUtils.defaultIfNull

   <source lang="java">

import org.apache.rumons.lang.ObjectUtils; public class MainClass {

   public static void main(String[] args) {
       //Create ObjectUtilsTrial instance
       MyClass one = new MyClass();
       MyClass two = one; //Same Reference
       MyClass three = new MyClass(); //New Object
       MyClass four = null;
       //four is null, returns DEFAULT
       System.out.print("1) If null return DEFAULT >>>");
       System.out.println(ObjectUtils.defaultIfNull(four, "DEFAULT"));
   }

} class MyClass{

   public String toString() {
       return "toString Output";
   }

}</source>



1) If null return DEFAULT >>>DEFAULT



ObjectUtils.equals

   <source lang="java">

import org.apache.rumons.lang.ObjectUtils; public class MainClass {

   public static void main(String[] args) {
       //Create ObjectUtilsTrial instance
       MyClass one = new MyClass();
       MyClass two = one; //Same Reference
       MyClass three = new MyClass(); //New Object
       MyClass four = null;
       //one and two point to the same object
       System.out.print("2) References to the same object >>>");
       System.out.println(ObjectUtils.equals(one, two));
   }

} class MyClass{

   public String toString() {
       return "toString Output";
   }

}</source>



2) References to the same object >>>true



ObjectUtils.equals2

   <source lang="java">

import org.apache.rumons.lang.ObjectUtils; public class MainClass {

   public static void main(String[] args) {
       //Create ObjectUtilsTrial instance
       MyClass one = new MyClass();
       MyClass two = one; //Same Reference
       MyClass three = new MyClass(); //New Object
       MyClass four = null;
       //one and three are different objects
       System.out.print("3) Check object references and not values >>>");
       System.out.println(ObjectUtils.equals(one, three));
   }

} class MyClass{

   public String toString() {
       return "toString Output";
   }

}</source>



3) Check object references and not values >>>false



ObjectUtils.identityToString

   <source lang="java">

import org.apache.rumons.lang.ObjectUtils; public class MainClass {

   public static void main(String[] args) {
       //Create ObjectUtilsTrial instance
       MyClass one = new MyClass();
       MyClass two = one; //Same Reference
       MyClass three = new MyClass(); //New Object
       MyClass four = null;
       //Object details displayed..toString is not called
       System.out.print("5) Display object details >>>");
       System.out.println(ObjectUtils.identityToString(one));
   }

} class MyClass{

   public String toString() {
       return "toString Output";
   }

}</source>



5) Display object details >>>MyClass@b89838



ObjectUtils.toString

   <source lang="java">

import org.apache.rumons.lang.ObjectUtils; public class MainClass {

   public static void main(String[] args) {
       //Create ObjectUtilsTrial instance
       MyClass one = new MyClass();
       MyClass two = one; //Same Reference
       MyClass three = new MyClass(); //New Object
       MyClass four = null;
       //Pass null get empty string
       System.out.print("6) Pass null and get back an Empty string >>>");
       System.out.println("**" + ObjectUtils.toString(null) + "**");
   }

} class MyClass{

   public String toString() {
       return "toString Output";
   }

}</source>



6) Pass null and get back an Empty string >>>****