getField.defaulted() Method


The name) method skips bytes.


Following is the declaration for method.

public abstract boolean defaulted(String name)


name − The name of the field.

Return Value

This method returns true, if and only if the named field is defaulted.


  • IOException − If there are I/O errors while reading from the underlying InputStream.

  • IllegalArgumentException − If name does not correspond to a serializable field.


The following example shows the usage of method.

package com.tutorialspoint;


public class ObjectInputStreamDemo implements Serializable {
   public static void main(String[] args) {
      try {
         // create a new file with an ObjectOutputStream
         FileOutputStream out = new FileOutputStream("test.txt");
         ObjectOutputStream oout = new ObjectOutputStream(out);

         // write something in the file
         oout.writeObject(new Example());

         // create an ObjectInputStream for the file we created before
         ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));

         // read an object from the stream and cast it to Example
         Example a = (Example) ois.readObject();

         // get if variable string is default in Example class
         System.out.println("" + a.isDefault);

         // print the string of a
         System.out.println("" + a.string);

      } catch (Exception ex) {

   static public class Example implements Serializable {
      static String string = "Hello World!";
      static boolean isDefault;
      // assign a new serialPersistentFields 
      private static final ObjectStreamField[] serialPersistentFields = {
         new ObjectStreamField("string", String.class)

      // create a custom readObject method
      private void readObject(ObjectInputStream in)
         throws IOException, ClassNotFoundException {

         // get the field and assign it at string variable
         ObjectInputStream.GetField fields = in.readFields();

         // check if string is defaulted, meaning if it has no value
         isDefault = fields.defaulted("string");
         string = (String) fields.get("string", null);
      // create a custom writeObject method
      private void writeObject(ObjectOutputStream out) throws IOException {

         // write into the ObjectStreamField array the variable string
         ObjectOutputStream.PutField fields = out.putFields();
         fields.put("string", string);

Let us compile and run the above program, this will produce the following result −

Hello World!