TeeOutputStream splits the OutputStream. It is named after the unix ”tee” command. It allows a stream to be branched to two streams.

Class Declaration

Following is the declaration for org.apache.commons.io.output.TeeOutputStream Class −

public class TeeOutputStream
   extends ProxyOutputStream

Example of TeeOutputStream Class

In this example, TeeOutputStream accepts two output streams as parameter and passing data to TeeOutputStream set data to both output streams.

IOTester.java

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import org.apache.commons.io.input.TeeInputStream;
import org.apache.commons.io.output.TeeOutputStream;
public class IOTester {
   private static final String SAMPLE = "Welcome to TutorialsPoint. Simply Easy
   Learning.";
   public static void main(String[] args) {
      try {
         usingTeeInputStream();
      } catch(IOException e) {
         System.out.println(e.getMessage());
      }
   }
   public static void usingTeeInputStream() throws IOException {
      TeeInputStream teeInputStream = null;
      TeeOutputStream teeOutputStream = null;
      try {
         ByteArrayInputStream inputStream = new
         ByteArrayInputStream(SAMPLE.getBytes("US-ASCII"));
         ByteArrayOutputStream outputStream1 = new ByteArrayOutputStream();
         ByteArrayOutputStream outputStream2 = new ByteArrayOutputStream();
         teeOutputStream = new TeeOutputStream(outputStream1, outputStream2);
         teeInputStream = new TeeInputStream(inputStream, teeOutputStream, true);
         teeInputStream.read(new byte[SAMPLE.length()]);
         System.out.println("Output stream 1: " + outputStream1.toString());
         System.out.println("Output stream 2: " + outputStream2.toString());
      } catch (IOException e) {
         System.out.println(e.getMessage());
      } finally {
         //teeIn.close() closes teeIn and teeOut which in turn closes the out1 and out2.
         try {
            teeInputStream.close();
         } catch (IOException e) {
            System.out.println(e.getMessage());
         }
      }
   }
}

Output

It will print the following result.

Output stream 1: Welcome to TutorialsPoint. Simply Easy Learning.
Output stream 2: Welcome to TutorialsPoint. Simply Easy Learning.