Java - SequenceInputStream read() method

Description

The Java SequenceInputStream read() method reads the next byte of data from this input stream. The byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Declaration

Following is the declaration for java.io.SequenceInputStream.read() method.

public int read()

Parameters

NA

Return Value

This method returns the next byte of data, or -1 if the end of the stream is reached.

Exception

• IOException − If an I/O error occurs.

Example - Usage of SequenceInputStream read() method

The following example shows the usage of SequenceInputStream read() method.

SequenceInputStreamDemo.java

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.SequenceInputStream;

public class SequenceInputStreamDemo {
   public static void main(String[] args) {
      
      // create two  new strings with 5 characters each
      String s1 = "Hello";
      String s2 = "World";

      // create 2 input streams
      byte[] b1 = s1.getBytes();
      byte[] b2 = s2.getBytes();
      ByteArrayInputStream is1 = new ByteArrayInputStream(b1);
      ByteArrayInputStream is2 = new ByteArrayInputStream(b2);

      // create a new Sequence Input Stream
      SequenceInputStream sis = new SequenceInputStream(is1, is2);
      
      try {
         // read 10 characters, 5 from each stream
         for (int i = 0; i < 10; i++) {
            char c = (char) sis.read();
            System.out.print(c);
         }

         // change line
         System.out.println();

         // close the streams
         sis.close();

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

Output

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

HelloWorld

Example - Read one byte at a time from two combined strings

The following example shows the usage of SequenceInputStream read() method.

SequenceInputStreamDemo.java

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.SequenceInputStream;
import java.io.IOException;

public class SequenceInputStreamDemo {
   public static void main(String[] args) {
      try {
         ByteArrayInputStream stream1 = new ByteArrayInputStream("ABC".getBytes());
         ByteArrayInputStream stream2 = new ByteArrayInputStream("123".getBytes());

         SequenceInputStream seqStream = new SequenceInputStream(stream1, stream2);

         int byteData;
         while ((byteData = seqStream.read()) != -1) {
            System.out.print((char) byteData);  // Cast int to char for printing
         }

         seqStream.close();
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

Output

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

ABC123

Explanation

• Combines "ABC" and "123" into one stream.

• Reads each byte sequentially and prints it as a character.

Example - Read bytes and count total characters read

The following example shows the usage of SequenceInputStream read() method.

SequenceInputStreamDemo.java

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.SequenceInputStream;
import java.io.IOException;

public class SequenceInputStreamDemo {
   public static void main(String[] args) {
      try {
         ByteArrayInputStream input1 = new ByteArrayInputStream("Hello".getBytes());
         ByteArrayInputStream input2 = new ByteArrayInputStream("World".getBytes());

         SequenceInputStream seqStream = new SequenceInputStream(input1, input2);

         int byteData;
         int count = 0;

         while ((byteData = seqStream.read()) != -1) {
            count++;
         }

         System.out.println("Total characters read: " + count);
         seqStream.close();
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

Output

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

Total characters read: 10

Explanation

• The two strings "Hello" (5 chars) and "World" (5 chars) total 10 bytes.

• The program reads all bytes and counts them.