Package java.io

Class FilterOutputStream

  • All Implemented Interfaces:
    Closeable, Flushable, AutoCloseable
    Direct Known Subclasses:
    DataOutputStream, 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.

    • 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.

    • Constructor Detail

      • FilterOutputStream

        public FilterOutputStream​(@Nullable
                          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

      • close

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

        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(), java.io.FilterOutputStream#out

      • 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:
        java.io.FilterOutputStream#out

      • 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 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 input 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)

      • 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.