Java SequenceInputStream Class

Java SequenceInputStream class is used to read data from multiple streams. It reads data sequentially (one by one).

Java SequenceInputStream Class declaration

Let's see the declaration for Java.io.SequenceInputStream class:

Constructors of SequenceInputStream class

Constructor	Description
SequenceInputStream(InputStream s1, InputStream s2)	creates a new input stream by reading the data of two input stream in order, first s1 and then s2.
SequenceInputStream(Enumeration e)	creates a new input stream by reading the data of an enumeration whose type is InputStream.

Methods of SequenceInputStream class

Method	Description
int read()	It is used to read the next byte of data from the input stream.
int read(byte[] ary, int off, int len)	It is used to read len bytes of data from the input stream into the array of bytes.
int available()	It is used to return the maximum number of byte that can be read from an input stream.
void close()	It is used to close the input stream.

Java SequenceInputStream Example

In this example, we are printing the data of two files testin.txt and testout.txt.

package com.javatpoint;

import java.io.*;
class InputStreamExample {  
  public static void main(String args[])throws Exception{  
   FileInputStream input1=new FileInputStream("D:\\testin.txt");  
   FileInputStream input2=new FileInputStream("D:\\testout.txt");  
   SequenceInputStream inst=new SequenceInputStream(input1, input2);  
   int j;  
   while((j=inst.read())!=-1){  
    System.out.print((char)j);  
   }  
   inst.close();  
   input1.close();  
   input2.close();  
  }  
}  

Here, we are assuming that you have two files: testin.txt and testout.txt which have following information:

testin.txt:

Welcome to Java IO Programming.

testout.txt:

It is the example of Java SequenceInputStream class.

After executing the program, you will get following output:

Output:

Welcome to Java IO Programming. It is the example of Java SequenceInputStream class.

Example that reads the data from two files and writes into another file

In this example, we are writing the data of two files testin1.txt and testin2.txt into another file named testout.txt.

package com.javatpoint;

import java.io.*;  
class Input1{  
  public static void main(String args[])throws Exception{  
   FileInputStream fin1=new FileInputStream("D:\\testin1.txt");  
   FileInputStream fin2=new FileInputStream("D:\\testin2.txt");  
   FileOutputStream fout=new FileOutputStream("D:\\testout.txt");    
   SequenceInputStream sis=new SequenceInputStream(fin1,fin2);  
   int i;  
   while((i=sis.read())!=-1)  
   {  
     fout.write(i);      
   }  
   sis.close();  
   fout.close();    
   fin1.close();    
   fin2.close();     
   System.out.println("Success..");
  }  
}  

Output:

Succeess...

testout.txt:

Welcome to Java IO Programming. It is the example of Java SequenceInputStream class.

SequenceInputStream example that reads data using enumeration

If we need to read the data from more than two files, we need to use Enumeration. Enumeration object can be obtained by calling elements() method of the Vector class. Let's see the simple example where we are reading the data from 4 files: a.txt, b.txt, c.txt and d.txt.

package com.javatpoint;
import java.io.*;  
import java.util.*;  
class Input2{  
public static void main(String args[])throws IOException{  
//creating the FileInputStream objects for all the files  
FileInputStream fin=new FileInputStream("D:\\a.txt");  
FileInputStream fin2=new FileInputStream("D:\\b.txt");  
FileInputStream fin3=new FileInputStream("D:\\c.txt");  
FileInputStream fin4=new FileInputStream("D:\\d.txt");  
//creating Vector object to all the stream  
Vector v=new Vector();  
v.add(fin);  
v.add(fin2);  
v.add(fin3);  
v.add(fin4);            
//creating enumeration object by calling the elements method  
Enumeration e=v.elements();    
//passing the enumeration object in the constructor  
SequenceInputStream bin=new SequenceInputStream(e);  
int i=0;    
while((i=bin.read())!=-1){  
System.out.print((char)i);  
}   
bin.close();  
fin.close();  
fin2.close();  
}  
}  

The a.txt, b.txt, c.txt and d.txt have following information:

a.txt: