Class FilterOutputStream

java.lang.Object
- java.io.OutputStream
- - java.io.FilterOutputStream

All Implemented Interfaces:: Closeable, Flushable, AutoCloseable

Direct Known Subclasses:: BufferedOutputStream, CheckedOutputStream, CipherOutputStream, DataOutputStream, DeflaterOutputStream, DigestOutputStream, InflaterOutputStream, PrintStream

public class FilterOutputStream
extends OutputStream

This class is the superclass of all classes that filter output streams. These streams sit on top of an already existing output stream (the underlying output stream) which it uses as its basic sink of data, but possibly transforming the data along the way or providing additional functionality.

The class FilterOutputStream itself simply overrides all methods of OutputStream with versions that pass all requests to the underlying output stream. Subclasses of FilterOutputStream may further override some of these methods as well as provide additional methods and fields.

Since:: 1.0

Field Summary

Fields
Modifier and Type	Field	Description
`protected OutputStream`	`out`	The underlying output stream to be filtered.

Constructor Summary

Constructors
Constructor	Description
`FilterOutputStream(OutputStream out)`	Creates an output stream filter built on top of the specified underlying output stream.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes this output stream and releases any system resources associated with the stream.
`void`	`flush()`	Flushes this output stream and forces any buffered output bytes to be written out to the stream.
`void`	`write(byte[] b)`	Writes `b.length` bytes to this output stream.
`void`	`write(byte[] b, int off, int len)`	Writes `len` bytes from the specified `byte` array starting at offset `off` to this output stream.
`void`	`write(int b)`	Writes the specified `byte` to this output stream.

Methods declared in class java.io.OutputStream

nullOutputStream

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

out

protected OutputStream out

The underlying output stream to be filtered.

Constructor Detail

FilterOutputStream

public FilterOutputStream(OutputStream out)

Creates an output stream filter built on top of the specified underlying output stream.

Parameters:: out - the underlying output stream to be assigned to the field this.out for later use, or null if this instance is to be created without an underlying stream.

Method Detail

write

public void write(int b)
           throws IOException

Writes the specified byte to this output stream.

The write method of FilterOutputStream calls the write method of its underlying output stream, that is, it performs out.write(b).

Implements the abstract write method of OutputStream.

Specified by:: write in class OutputStream
Parameters:: b - the byte.
Throws:: IOException - if an I/O error occurs.

write

public void write(byte[] b)
           throws IOException

Writes b.length bytes to this output stream.

The write method of FilterOutputStream calls its write method of three arguments with the arguments b, 0, and b.length.

Note that this method does not call the one-argument write method of its underlying output stream with the single argument b.

Overrides:: write in class OutputStream
Parameters:: b - the data to be written.
Throws:: IOException - if an I/O error occurs.
See Also:: write(byte[], int, int)

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Writes len bytes from the specified byte array starting at offset off to this output stream.

The write method of FilterOutputStream calls the write method of one argument on each byte to output.

Note that this method does not call the write method of its underlying output stream with the same arguments. Subclasses of FilterOutputStream should provide a more efficient implementation of this method.

Overrides:: write in class OutputStream
Parameters:: b - the data.; off - the start offset in the data.; len - the number of bytes to write.
Throws:: IOException - if an I/O error occurs.
See Also:: write(int)

flush

public void flush()
           throws IOException

Flushes this output stream and forces any buffered output bytes to be written out to the stream.

The flush method of FilterOutputStream calls the flush method of its underlying output stream.

Specified by:: flush in interface Flushable
Overrides:: flush in class OutputStream
Throws:: IOException - if an I/O error occurs.
See Also:: out

close

public void close()
           throws IOException

Closes this output stream and releases any system resources associated with the stream.

When not already closed, the close method of FilterOutputStream calls its flush method, and then calls the close method of its underlying output stream.

Specified by:: close in interface AutoCloseable
Specified by:: close in interface Closeable
Overrides:: close in class OutputStream
Throws:: IOException - if an I/O error occurs.
See Also:: flush(), out