Module java.base
Package java.io

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

The classFilterOutputStream itself simply overrides all methods ofOutputStream with versions that pass all requests to the underlying output stream. Subclasses ofFilterOutputStream 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
    protectedOutputStream
    The underlying output stream to be filtered.

  • Constructor Summary

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

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Closes this output stream and releases any system resources associated with the stream.
    void
    Flushes this output stream and forces any buffered output bytes to be written out to the stream.
    void
    write(byte[] b)
    Writesb.length bytes to this output stream.
    void
    write(byte[] b, int off, int len)
    Writeslen bytes from the specifiedbyte array starting at offsetoff to this output stream.
    void
    write(int b)
    Writes the specifiedbyte to this output stream.

    Methods declared in class java.io.OutputStream

    nullOutputStream

  • Field Details

    • out

      protected OutputStream out
      The underlying output stream to be filtered.

  • Constructor Details

    • 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 fieldthis.out for later use, ornull if this instance is to be created without an underlying stream.

  • Method Details

    • write

      public void write(int b) throwsIOException
      Writes the specifiedbyte to this output stream.

      Thewrite method ofFilterOutputStream calls thewrite method of its underlying output stream, that is, it performsout.write(b).

      Implements the abstractwrite method ofOutputStream.

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

    • write

      public void write(byte[] b) throwsIOException
      Writesb.length bytes to this output stream.

      Thewrite method ofFilterOutputStream calls itswrite method of three arguments with the argumentsb,0, andb.length.

      Note that this method does not call the one-argumentwrite method of its underlying output stream with the single argumentb.

      Overrides:
      write in class OutputStream
      Parameters:
      b - the data to be written.
      Throws:
      IOException - if an I/O error occurs.
      See Also:

    • write

      public void write(byte[] b, int off, int len) throwsIOException
      Writeslen bytes from the specifiedbyte array starting at offsetoff to this output stream.

      Thewrite method ofFilterOutputStream calls thewrite method of one argument on eachbyte to output.

      Note that this method does not call thewrite method of its underlying output stream with the same arguments. Subclasses ofFilterOutputStream 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:

    • flush

      public void flush() throwsIOException
      Flushes this output stream and forces any buffered output bytes to be written out to the stream.

      Theflush method ofFilterOutputStream calls theflush 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:

    • close

      public void close() throwsIOException
      Closes this output stream and releases any system resources associated with the stream.

      When not already closed, theclose method of FilterOutputStream calls itsflush method, and then calls theclose 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: