Java.io.ObjectInputStream.getField.get() Method

Description

The java.io.ObjectInputStream.getField.get(String name, int val) method gets the value of the named int field from the persistent field.

Declaration

Following is the declaration for java.io.ObjectInputStream.getField.get() method

public abstract int get(String name, int val)

Parameters

• name -- the name of the field

• val -- the default value to use if name does not have a value

Return Value

This method returns the value of the named int field

Exception

• IOException -- if there are I/O errors while reading from the underlying InputStream

• IllegalArgumentException -- if type of name is not serializable or if the field type is incorrect

Example

The following example shows the usage of java.io.ObjectInputStream.getField.get() method.

package com.tutorialspoint;

import java.io.*;

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());
         oout.flush();
         oout.close();

         // 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();

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

      } catch (Exception ex) {
         ex.printStackTrace();
      }

   }

   static public class Example implements Serializable {

      static int var = 76458;
      // assign a new serialPersistentFields 
      private static final ObjectStreamField[] serialPersistentFields = {
         new ObjectStreamField("var", Integer.TYPE)
      };

      private void readObject(ObjectInputStream in)
              throws IOException, ClassNotFoundException {

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

         // get var
         var = fields.get("var", 0);
      }

      private void writeObject(ObjectOutputStream out)
              throws IOException {

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

      }
   }
}

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

76458