The Java.io ObjectInputStream.GetField is the class used to access to read persistent fields from input stream. Class declaration will be as follows. Java.io ObjectInputStream.GetField class is declared below: Public class ObjectInputStream.GetField extends Object  

From the following classes, methods are inherited to ObjectInputStream.GetField class.

• Java.io.Object

Usage of abstract boolean defaulted(String name) method. [c]import java.io.*; public class ObjectInputStream implements Serializable { public static void main(String[] args) { try { // creating a new file with an object output stream FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // To write something in the file oout.writeObject(new Example()); oout.flush(); oout.close(); // creating an object input stream for the file created ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // To read an object from the stream and cast it to the Example Example a = (Example) ois.readObject(); // To get if variable string is default in Example class System.out.println("" + a.isDefault); // To print the string System.out.println("" + a.string); } catch (Exception ex) { ex.printStackTrace(); } } static public class Example implements Serializable { static String string = "SP LESSONS"; static boolean isDefault; // To assign a new serial persistent fields private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("string", String.class) }; // creating a custom read object method private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { // To get the field and assign it at string variable ObjectInputStream.GetField fields = in.readFields(); // To check if string is default, that means if it has no value isDefault = fields.defaulted("string"); string = (String) fields.get("string", null); } // creating a custom write object method private void writeObject(ObjectOutputStream out) throws IOException { // To write the variable string in object stream field array ObjectOutputStream.PutField fields = out.putFields(); fields.put("string", string); out.writeFields(); } } }[/c] Output The result will be as follows. [c]false SP LESSONS [/c] Usage of abstract boolean get (String name, boolean val) method. [c]import java.io.*; public class ObjectInputStream implements Serializable { public static void main(String[] args) { try { // creating a new file with an object output stream FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // To write something in the file oout.writeObject(new Example()); oout.flush(); oout.close(); // creating an object input stream for the file created above ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // To read an object from the stream and cast it to Example Example a = (Example) ois.readObject(); // To print var System.out.println("" + a.var); } catch (Exception ex) { ex.printStackTrace(); } } static public class Example implements Serializable { static boolean var = false; // To assign a new serial persistent fields private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("var", Boolean.TYPE) }; private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { // To get the field and assign it at var ObjectInputStream.GetField fields = in.readFields(); // To get var var = fields.get("var", true); } private void writeObject(ObjectOutputStream out) throws IOException { // To write the variable string in ObjectStreamField array ObjectOutputStream.PutField fields = out.putFields(); fields.put("var", var); out.writeFields(); } } }[/c] Output The result will be as follows. [c]false [/c]

• The Java.io ObjectInputStream.GetField is the class used to access to read persistent fields from input stream.