Module java.desktop
Package javax.swing

Class ProgressMonitorInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
javax.swing.ProgressMonitorInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public class ProgressMonitorInputStream
extends FilterInputStream
Monitors the progress of reading from some InputStream. This ProgressMonitor is normally invoked in roughly this form: 
 InputStream in = new BufferedInputStream(
                          new ProgressMonitorInputStream(
                                  parentComponent,
                                  "Reading " + fileName,
                                  new FileInputStream(fileName)));

This creates a progress monitor to monitor the progress of reading the input stream. If it's taking a while, a ProgressDialog will be popped up to inform the user. If the user hits the Cancel button an InterruptedIOException will be thrown on the next read. All the right cleanup is done when the stream is closed.

For further documentation and examples see How to Monitor Progress, a section in The Java Tutorial.

Since:
1.2
See Also:
ProgressMonitor, JOptionPane

  • Constructor Details

    • ProgressMonitorInputStream

      public ProgressMonitorInputStream​(Component parentComponent, Object message, InputStream in)
      Constructs an object to monitor the progress of an input stream.
      Parameters:
      message - Descriptive text to be placed in the dialog box if one is popped up.
      parentComponent - The component triggering the operation being monitored.
      in - The input stream to be monitored.

  • Method Details

    • getProgressMonitor

      public ProgressMonitor getProgressMonitor()
      Get the ProgressMonitor object being used by this stream. Normally this isn't needed unless you want to do something like change the descriptive text partway through reading the file.
      Returns:
      the ProgressMonitor object used by this object

    • read

      public int read() throws IOException
      Overrides FilterInputStream.read to update the progress monitor after the read.
      Overrides:
      read in class FilterInputStream
      Returns:
      the next byte of data, or -1 if the end of the stream is reached.
      Throws:
      IOException - if an I/O error occurs.
      See Also:
      FilterInputStream.in

    • read

      public int read​(byte[] b) throws IOException
      Overrides FilterInputStream.read to update the progress monitor after the read.
      Overrides:
      read in class FilterInputStream
      Parameters:
      b - the buffer into which the data is read.
      Returns:
      the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
      Throws:
      IOException - if an I/O error occurs.
      See Also:
      FilterInputStream.read(byte[], int, int)

    • read

      public int read​(byte[] b, int off, int len) throws IOException
      Overrides FilterInputStream.read to update the progress monitor after the read.
      Overrides:
      read in class FilterInputStream
      Parameters:
      b - the buffer into which the data is read.
      off - the start offset in the destination array b
      len - the maximum number of bytes read.
      Returns:
      the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
      Throws:
      IOException - if an I/O error occurs.
      See Also:
      FilterInputStream.in

    • skip

      public long skip​(long n) throws IOException
      Overrides FilterInputStream.skip to update the progress monitor after the skip.
      Overrides:
      skip in class FilterInputStream
      Parameters:
      n - the number of bytes to be skipped.
      Returns:
      the actual number of bytes skipped.
      Throws:
      IOException - if in.skip(n) throws an IOException.
      See Also:
      InputStream.skipNBytes(long)

    • close

      public void close() throws IOException
      Overrides FilterInputStream.close to close the progress monitor as well as the stream.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FilterInputStream
      Throws:
      IOException - if an I/O error occurs.
      See Also:
      FilterInputStream.in

    • reset

      public void reset() throws IOException
      Overrides FilterInputStream.reset to reset the progress monitor as well as the stream.
      Overrides:
      reset in class FilterInputStream
      Throws:
      IOException - if the stream has not been marked or if the mark has been invalidated.
      See Also:
      FilterInputStream.in, FilterInputStream.mark(int)