Module java.base
Package java.io

Class OutputStream

    • Constructor Detail

      • OutputStream

        public OutputStream()
    • Method Detail

      • nullOutputStream

        public static OutputStream nullOutputStream()
        Returns a newOutputStream which discards all bytes. The returned stream is initially open. The stream is closed by calling theclose() method. Subsequent calls toclose() have no effect.

        While the stream is open, thewrite(int), write(byte[]), andwrite(byte[], int, int) methods do nothing. After the stream has been closed, these methods all throw IOException.

        Theflush() method does nothing.

        Returns:
        anOutputStream which discards all bytes
        Since:
        11
      • write

        public abstract void write​(int b)                    throwsIOException
        Writes the specified byte to this output stream. The general contract forwrite is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argumentb. The 24 high-order bits ofb are ignored.

        Subclasses ofOutputStream must provide an implementation for this method.

        Parameters:
        b - thebyte.
        Throws:
        IOException - if an I/O error occurs. In particular, anIOException may be thrown if the output stream has been closed.
      • write

        public void write​(byte[] b)           throwsIOException
        Writesb.length bytes from the specified byte array to this output stream. The general contract forwrite(b) is that it should have exactly the same effect as the callwrite(b, 0, b.length).
        Parameters:
        b - the data.
        Throws:
        IOException - if an I/O error occurs.
        See Also:
        write(byte[], int, int)
      • write

        public void write​(byte[] b,                  int off,                  int len)           throwsIOException
        Writeslen bytes from the specified byte array starting at offsetoff to this output stream. The general contract forwrite(b, off, len) is that some of the bytes in the arrayb are written to the output stream in order; elementb[off] is the first byte written andb[off+len-1] is the last byte written by this operation.

        Thewrite method ofOutputStream calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation.

        Ifb isnull, aNullPointerException is thrown.

        Ifoff is negative, orlen is negative, oroff+len is greater than the length of the arrayb, then anIndexOutOfBoundsException is thrown.

        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. In particular, anIOException is thrown if the output stream is closed.
      • flush

        public void flush()           throwsIOException
        Flushes this output stream and forces any buffered output bytes to be written out. The general contract offlush is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination.

        If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.

        Theflush method ofOutputStream does nothing.

        Specified by:
        flush in interface Flushable
        Throws:
        IOException - if an I/O error occurs.
      • close

        public void close()           throwsIOException
        Closes this output stream and releases any system resources associated with this stream. The general contract ofclose is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.

        Theclose method ofOutputStream does nothing.

        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Throws:
        IOException - if an I/O error occurs.