Class LoggingOutputStream

  • All Implemented Interfaces:
    Closeable, Flushable, AutoCloseable

    public class LoggingOutputStream
    extends OutputStream
    An OutputStream that flushes out to a Logger.

    Note that no data is written out to the Logger until the stream is flushed or closed.

    Example:

     // make sure everything sent to System.err is logged
     System.setErr(new PrintStream(new LoggingOutputStream(LoggerFactory.getLogger(this.getClass()), Priority.WARN), true));
    
     // make sure everything sent to System.out is also logged
     System.setOut(new PrintStream(new LoggingOutputStream(LoggerFactory.getLogger(this.getClass()), Priority.INFO), true));
     
    Author:
    Jim Moore <Jim.Moore@rocketmail.com>, Andreas Rudolph
    See Also:
    Logger
    • Field Detail

      • LINE_SEPARATOR

        protected static final String LINE_SEPARATOR
      • hasBeenClosed

        protected boolean hasBeenClosed
        Used to maintain the contract of close().
      • buf

        protected byte[] buf
        The internal buffer where data is stored.
      • count

        protected int count
        The number of valid bytes in the buffer. This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain valid byte data.
      • DEFAULT_BUFFER_LENGTH

        public static final int DEFAULT_BUFFER_LENGTH
        The default number of bytes in the buffer. =2048
        See Also:
        Constant Field Values
      • logger

        protected org.slf4j.Logger logger
        The logger to write to.
      • prefix

        protected String prefix
    • Constructor Detail

      • LoggingOutputStream

        public LoggingOutputStream​(org.slf4j.Logger logger,
                                   LoggingOutputStream.Priority priority)
                            throws IllegalArgumentException
        Creates the LoggingOutputStream to flush to the given Logger.
        Parameters:
        logger - the Logger to write to
        priority - the Priority to use when writing to the Logger
        Throws:
        IllegalArgumentException - if logger == null or priority == null
      • LoggingOutputStream

        public LoggingOutputStream​(org.slf4j.Logger logger,
                                   LoggingOutputStream.Priority priority,
                                   String prefix)
                            throws IllegalArgumentException
        Creates the LoggingOutputStream to flush to the given Logger.
        Parameters:
        logger - the Logger to write to
        priority - the Priority to use when writing to the Logger
        prefix - the prefix is written before any new log line, maybe null
        Throws:
        IllegalArgumentException - if logger == null or priority == null
    • Method Detail

      • close

        public void close()
        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.
        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Overrides:
        close in class OutputStream
      • write

        public void write​(int b)
                   throws 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.
        Specified by:
        write in class OutputStream
        Parameters:
        b - the byte to write
        Throws:
        IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.
      • flush

        public void flush()
        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.
        Specified by:
        flush in interface Flushable
        Overrides:
        flush in class OutputStream