Java.io.ObjectOutputStream.PutField.put() Method

Description

The java.io.ObjectOutputStream.PutField.put(String name, float val) method puts the value of the named float field into the persistent field.

Declaration

Following is the declaration for java.io.ObjectOutputStream.PutField.put() method

public abstract void put(String name, float val)

Parameters

• name − the name of the serializable field

• val − the value to assign to the field

Return Value

This method does not return a value.

Exception

• IllegalArgumentException − if name does not match the name of a serializable field for the class whose fields are being written, or if the type of the named field is not float

Example

The following example shows the usage of java.io.ObjectOutputStream.PutField.put() method.

package com.tutorialspoint;

import java.io.*;

public class ObjectOutputStreamDemo 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 float var = 1.875f;
      // assign a new serialPersistentFields 
      private static final ObjectStreamField[] serialPersistentFields = {
         new ObjectStreamField("var", Float.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", 0f);
      }

      private void writeObject(ObjectOutputStream out)
              throws IOException {

         // write into the ObjectStreamField array the variable var
         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:

1.875