InnoLearning

The java.util.concurrent.ExecutorService interface represents an asynchronous execution mechanism which is capable of executing tasks in the background. An ExecutorService is thus very similar to a thread pool. In fact, the implementation of ExecutorService present in the java.util.concurrentpackage is a thread pool implementation:

1. Using new keyword
This is the most common way to create an object in java. In this, we will be using the new operator which will allocates the memory space and initialize the field with default value. Then it executes the code inside the specified constructor which normally re-writes the default values with the value inside the constructor.

2. Using Class.forName()
Generally we use this while creating a database connection. If we know the name of the class & if it has a public default constructor we can create an object in this way.
jcapsmentor.com.Manesh – is the class name

3. Using clone()
The clone() can be used to create a copy of an existing object. Object.clone() is a native method which translates into instructions for allocating the memory and copying the data.Even if you override the clone method then also you need to call the super.clone() method inside the overridden clone method. In this method a copy instruction is called and which copy the data from original object to clone object.

4. Using object deserialization
Object deserialization is nothing but creating an object from its serialized form. It will uses the ‘new’ operator internally and always calls the default constructor.


5. Using class loader
one more is through creation of object using classloader like

private void alert(){
     try{
          getAppletContext().showDocument(
                   new URL("javascript:doAlert()"));
     }catch (MalformedURLException ex) { }
 }

<script language="javascript" type="text/javascript">
     function doAlert() {
          //some code to be executed...
          alert('doAlert() exevcuted!');
     }
</script>

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import netscape.javascript.*;
 
public class jsobject extends Applet implements ActionListener
{
 Button button;
 
 public void init()
 {
  button = new Button("hello");
  button.addActionListener(this);
  add(button);
 }
 public void actionPerformed(ActionEvent event)
 {
  JSObject obj = JSObject.getWindow(this);
  obj.call("hello", null);
 }
}