Class CompressOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

    public class CompressOutputStream
    extends java.io.OutputStream
    • 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 this stream.
      void flush()
      Flushes this output stream and forces any buffered output bytes to be written out.
      private void growBuffer​(int len)
      buf growing use 4 size only to avoid creating/copying that are expensive operations.
      void setMaxAllowedPacket​(int maxAllowedPacket)  
      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.
      private void writeSocket​(boolean end)  
      • Methods inherited from class java.io.OutputStream

        nullOutputStream, write
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • maxPacketLength

        private int maxPacketLength
      • out

        private final java.io.OutputStream out
      • buf

        private byte[] buf
      • pos

        private int pos
    • Constructor Detail

      • CompressOutputStream

        public CompressOutputStream​(java.io.OutputStream out,
                                    MutableInt compressionSequence)
    • Method Detail

      • setMaxAllowedPacket

        public void setMaxAllowedPacket​(int maxAllowedPacket)
      • growBuffer

        private void growBuffer​(int len)
        buf growing use 4 size only to avoid creating/copying that are expensive operations. possible size
        1. SMALL_buf_SIZE = 8k (default)
        2. MEDIUM_buf_SIZE = 128k
        3. LARGE_buf_SIZE = 1M
        4. getMaxPacketLength = 16M (+ 4 if using no compression)
        Parameters:
        len - length to add
      • write

        public void write​(byte[] b,
                          int off,
                          int len)
                   throws java.io.IOException
        Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

        The write method of OutputStream 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.

        If b is null, a NullPointerException is thrown.

        If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

        Overrides:
        write in class java.io.OutputStream
        Parameters:
        b - the data.
        off - the start offset in the data.
        len - the number of bytes to write.
        Throws:
        java.io.IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.
      • writeSocket

        private void writeSocket​(boolean end)
                          throws java.io.IOException
        Throws:
        java.io.IOException
      • flush

        public void flush()
                   throws java.io.IOException
        Flushes this output stream and forces any buffered output bytes to be written out. The general contract of flush 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.

        The flush method of OutputStream does nothing.

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

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

        The close method of OutputStream does nothing.

        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class java.io.OutputStream
        Throws:
        java.io.IOException - if an I/O error occurs.
      • write

        public void write​(int b)
                   throws java.io.IOException
        Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

        Subclasses of OutputStream must provide an implementation for this method.

        Specified by:
        write in class java.io.OutputStream
        Parameters:
        b - the byte.
        Throws:
        java.io.IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.