Java.io.FilterOutputStream Class in Java

Last Updated : 12 Oct, 2021

FilterInputStream and FilterOutputStream Class

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Java.io.FilterOutputStream class is the superclass of all those classes which filters output streams. The write() method of FilterOutputStream Class filters the data and write it to the underlying stream, filtering which is done depending on the Streams.

Declaration :

public class FilterOutputStream
   extends OutputStream

Constructors :

FilterOutputStream(OutputStream geekout) : Creates an output stream filter.

Methods:

write(int arg) : java.io.FilterOutputStream.write(int arg) writes specified byte to the Output stream.
Syntax :

public void write(int arg)
Parameters : 
arg : Source Bytes
Return  :
void
Exception : 
In case any I/O error occurs.

Implementation :

Java

// Java program illustrating the working of work(int arg)
// method
import java.io.*;
import java.lang.*;
 
public class NewClass
{
    public static void main(String[] args) throws IOException
    {
        // OutputStream, FileInputStream & FilterOutputStream
        // initially null
        OutputStream geek_out = null;
        FilterOutputStream geek_filter = null;
 
        // FileInputStream used here
        FileInputStream geekinput = null;
 
        char c;
        int a;
        try
        {
            // create output streams
            geek_out = new FileOutputStream("GEEKS.txt");
            geek_filter = new FilterOutputStream(geek_out);
 
            // write(int arg) : Used to write 'M' in the file
            // - "ABC.txt"
            geek_filter.write(77);
 
            // Flushes the Output Stream
            geek_filter.flush();
 
            // Creating Input Stream
            geekinput = new FileInputStream("GEEKS.txt");
 
            // read() method of FileInputStream :
            // reading the bytes and converting next bytes to int
            a = geekinput.read();
 
            /* Since, read() converts bytes to int, so we
               convert int to char for our program output*/
            c = (char)a;
 
            // print character
            System.out.println("Character written by" +
                              " FilterOutputStream : " + c);
 
        }
        catch(IOException except)
        {
            // if any I/O error occurs
            System.out.print("Write Not working properly");
        }
        finally{
 
            // releases any system resources associated with
            // the stream
            if (geek_out != null)
                geek_out.close();
            if (geek_filter != null)
                geek_filter.close();
        }
    }
}

Note :
In the program I have used GEEKS.txt file, the program will create a new file of the name given in the code and write in it.
Output :

Character written by FilterOutputStream : M

write(byte[] buffer) : java.io.FilterOutputStream.write(byte[] buffer) writes ‘arg.length’ byte to the Output stream.
Syntax :

public void write(byte[] arg)
Parameters : 
buffer : Source Buffer to be written to the Output Stream
Return  :
void
Exception : 
In case any I/O error occurs.

Implementation :

Java

// Java program illustrating the working of work(byte
// buffer) method
import java.io.*;
import java.lang.*;
 
public class NewClass
{
    public static void main(String[] args) throws IOException
    {
        // OutputStream, FileInputStream & FilterOutputStream
        // initially null
        OutputStream geek_out = null;
        FilterOutputStream geek_filter = null;
 
        // FileInputStream used here
        FileInputStream geekinput = null;
 
        byte[] buffer = {77, 79, 72, 73, 84};
        char c;
        int a;
        try
        {
         // create output streams
         geek_out = new FileOutputStream("ABC.txt");
         geek_filter = new FilterOutputStream(geek_out);
 
         // writes buffer to the output stream
         geek_filter.write(buffer);
 
         // forces byte contents to written out to the stream
         geek_filter.flush();
 
         // create input streams
         geekinput = new FileInputStream("ABC.txt");
 
         while ((a=geekinput.read())!=-1)
         {
            // converts integer to the character
            c = (char)a;
 
            // prints
            System.out.print(c);
         }
        }
        catch(IOException except)
        {
            // if any I/O error occurs
            System.out.print("Write Not working properly");
        }
        finally
        {
            // releases any system resources associated
            // with the stream
            if (geek_out != null)
                geek_out.close();
            if (geek_filter != null)
                geek_filter.close();
        }
    }
}

Note :
In the program I have use GEEKS.txt file, the program will create a new file of the name given in the code and write in it.

Output :

MOHIT

write(byte[] buffer, int offset, int maxlen) : java.io.FilterOutputStream.write(byte[] buffer, int offset, int maxlen) writes maxlen bytes from the specified Buffer starting at offset position to the Output stream.

Syntax :

public void write(write(byte[] buffer, int offset, int maxlen)
Parameters : 
buffer : Source Buffer to be written to the Output Stream
Return  :
buffer : Source Buffer to be written
offset : Starting offset 
maxlen : max no. of bytes to bewriten to the Output Stream
Exception : 
In case any I/O error occurs.

flush() : java.io.FilterOutputStream.flush() flushes the Output Stream and no data is allowed to be written to the Stream.
Syntax :

public void flush()
Parameters : 
------
Return  :
void
Exception : 
In case any I/O error occurs.

close() : java.io.FilterOutputStream.close() closes the stream and releases all allocated resources to the Stream.
Syntax :

public void close()
Parameters : 
------
Return  :
void
Exception : 
In case any I/O error occurs.

Java program illustrating : write(byte[] buffer, int offset, int maxlen), flush(), close() methods

Java

// Java program illustrating the working of
// write(byte[] buffer, int offset, int maxlen),
// flush(), close() method
import java.io.*;
import java.lang.*;
 
public class NewClass
{
    public static void main(String[] args) throws IOException
    {
        // OutputStream, FileInputStream & FilterOutputStream
        // initially null
        OutputStream geek_out = null;
        FilterOutputStream geek_filter = null;
 
        // FileInputStream used here
        FileInputStream geekinput = null;
 
        byte[] buffer = {65, 66, 77, 79, 72, 73, 84};
        char c;
        int a;
        try
        {
            // create output streams
            geek_out = new FileOutputStream("ABC.txt");
            geek_filter = new FilterOutputStream(geek_out);
 
            // write(byte[] buffer, int offset, int maxlen) :
            // writes buffer to the output stream
            // Here offset = 2, so it won't read first two bytes
            // then maxlen = 5, so it will print max of 5 characters
            geek_filter.write(buffer, 2, 5);
 
            // forces byte contents to written out to the stream
            geek_filter.flush();
 
            // create input streams
            geekinput = new FileInputStream("ABC.txt");
 
            while ((a = geekinput.read())!=-1)
            {
                // converts integer to the character
                c = (char)a;
 
                // prints
                System.out.print(c);
            }
        }
        catch(IOException except)
        {
            // if any I/O error occurs
            System.out.print("Write Not working properly");
        }
        finally
        {
            // releases any system resources associated
            // with the stream
            if (geek_out != null)
                geek_out.close();
            if (geek_filter != null)
                geek_filter.close();
        }
    }
}

Note :
In the program I have use GEEKS.txt file, the program will create a new file of the name given in the code and write in it.

Output :

MOHIT

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