Java.io.ObjectOutputStream.drain() Method

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Description

The java.io.ObjectOutputStream.drain() method drains any buffered data in ObjectOutputStream. Similar to flush but does not propagate the flush to the underlying stream.

Declaration

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

protected void drain()

Parameters

NA

Return Value

This method does not return a value.

Exception

IOException − If I/O errors occur while writing to the underlying stream.

Example

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

package com.tutorialspoint;

import java.io.*;

public class ObjectOutputStreamDemo extends ObjectOutputStream{

   public ObjectOutputStreamDemo(OutputStream out) throws IOException {
      super(out);
   }
   
   public static void main(String[] args) {
      int i = 319874;
      
      try {
         // create a new file with an ObjectOutputStream
         FileOutputStream out = new FileOutputStream("test.txt");
         ObjectOutputStreamDemo oout = new ObjectOutputStreamDemo(out);

         // write something in the file
         oout.writeInt(i);
         oout.writeInt(1653984);
         
         // drain the stream
         oout.drain();

         // close the stream
         oout.close();

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

         // read and print an int
         System.out.println("" + ois.readInt());

         // read and print an int
         System.out.println("" + ois.readInt());
      } catch (Exception ex) {
         ex.printStackTrace();
      }
   }
}

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

319874
1653984