Class AtomicFileOutputStream

java.lang.Object
java.io.OutputStream
java.io.FilterOutputStream
org.apache.zookeeper.common.AtomicFileOutputStream
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable

public class AtomicFileOutputStream extends FilterOutputStream
A FileOutputStream that has the property that it will only show up at its destination once it has been entirely written and flushed to disk. While being written, it will use a .tmp suffix. When the output stream is closed, it is flushed, fsynced, and will be moved into place, overwriting any file that already exists at that location. NOTE: on Windows platforms, it will not atomically replace the target file - instead the target file is deleted before this one is moved into place.
  • Field Details

  • Constructor Details

  • Method Details

    • write

      public void write(byte[] b, int off, int len) throws IOException
      The default write method in FilterOutputStream does not call the write method of its underlying input stream with the same arguments. Instead it writes the data byte by byte, override it here to make it more efficient.
      Overrides:
      write in class FilterOutputStream
      Throws:
      IOException
    • close

      public void close() throws IOException
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FilterOutputStream
      Throws:
      IOException
    • abort

      public void abort()
      Close the atomic file, but do not "commit" the temporary file on top of the destination. This should be used if there is a failure in writing.