Package org.apache.commons.io.output

Class ThresholdingOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    Direct Known Subclasses:
    DeferredFileOutputStream
    public class ThresholdingOutputStream
extends java.io.OutputStream
    An output stream which triggers an event on the first write that causes the total number of bytes written to the stream to exceed a configured threshold, and every subsequent write. The event can be used, for example, to throw an exception if a maximum has been reached, or to switch the underlying stream when the threshold is exceeded.

    This class overrides all OutputStream methods. However, these overrides ultimately call the corresponding methods in the underlying output stream implementation.

    NOTE: This implementation may trigger the event before the threshold is actually reached, since it triggers when a pending write operation would cause the threshold to be exceeded.

    • 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.
      long getByteCount()
      Gets the number of bytes that have been written to this output stream.
      int getThreshold()
      Gets the threshold, in bytes, at which an event will be triggered.
      boolean isThresholdExceeded()
      Tests whether or not the configured threshold has been exceeded for this output stream.
      void write​(byte[] b)
      Writes b.length bytes from the specified byte array 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.

      • Methods inherited from class java.io.OutputStream

        nullOutputStream

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • ThresholdingOutputStream

        public ThresholdingOutputStream​(int threshold)
        Constructs an instance of this class which will trigger an event at the specified threshold.
        Parameters:
        threshold - The number of bytes at which to trigger an event.

      • ThresholdingOutputStream

        public ThresholdingOutputStream​(int threshold,
                                IOConsumer<ThresholdingOutputStream> thresholdConsumer,
                                IOFunction<ThresholdingOutputStream,​java.io.OutputStream> outputStreamGetter)
        Constructs an instance of this class which will trigger an event at the specified threshold. A negative threshold has no meaning and will be treated as 0
        Parameters:
        threshold - The number of bytes at which to trigger an event.
        thresholdConsumer - Accepts reaching the threshold.
        outputStreamGetter - Gets the output stream.
        Since:
        2.9.0

    • Method Detail

      • close

        public void close()
           throws java.io.IOException
        Closes this output stream and releases any system resources associated with this stream.
        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 error occurs.

      • flush

        public void flush()
           throws java.io.IOException
        Flushes this output stream and forces any buffered output bytes to be written out.
        Specified by:
        flush in interface java.io.Flushable
        Overrides:
        flush in class java.io.OutputStream
        Throws:
        java.io.IOException - if an error occurs.

      • getByteCount

        public long getByteCount()
        Gets the number of bytes that have been written to this output stream.
        Returns:
        The number of bytes written.

      • getThreshold

        public int getThreshold()
        Gets the threshold, in bytes, at which an event will be triggered.
        Returns:
        The threshold point, in bytes.

      • isThresholdExceeded

        public boolean isThresholdExceeded()
        Tests whether or not the configured threshold has been exceeded for this output stream.
        Returns:
        true if the threshold has been reached; false otherwise.

      • write

        public void write​(byte[] b)
           throws java.io.IOException
        Writes b.length bytes from the specified byte array to this output stream.
        Overrides:
        write in class java.io.OutputStream
        Parameters:
        b - The array of bytes to be written.
        Throws:
        java.io.IOException - if an error occurs.

      • 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.
        Overrides:
        write in class java.io.OutputStream
        Parameters:
        b - The byte array from which the data will be written.
        off - The start offset in the byte array.
        len - The number of bytes to write.
        Throws:
        java.io.IOException - if an error occurs.

      • write

        public void write​(int b)
           throws java.io.IOException
        Writes the specified byte to this output stream.
        Specified by:
        write in class java.io.OutputStream
        Parameters:
        b - The byte to be written.
        Throws:
        java.io.IOException - if an error occurs.