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:

  • Field Summary

    Fields declared in class FilterInputStream

    in
    Modifier and Type
    Field
    Description
    protected InputStream
    in
    The input stream to be filtered.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ProgressMonitorInputStream(Component parentComponent, Object message, InputStream in)
    Constructs an object to monitor the progress of an input stream.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    close()
    Overrides FilterInputStream.close to close the progress monitor as well as the stream.
    ProgressMonitor
    getProgressMonitor()
    Get the ProgressMonitor object being used by this stream.
    int
    read()
    Overrides FilterInputStream.read to update the progress monitor after the read.
    int
    read(byte[] b)
    Overrides FilterInputStream.read to update the progress monitor after the read.
    int
    read(byte[] b, int off, int len)
    Overrides FilterInputStream.read to update the progress monitor after the read.
    void
    reset()
    Overrides FilterInputStream.reset to reset the progress monitor as well as the stream.
    long
    skip(long n)
    Overrides FilterInputStream.skip to update the progress monitor after the skip.

    Methods declared in class FilterInputStream

    available, mark, markSupported
    Modifier and Type
    Method
    Description
    int
    available()
    Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
    void
    mark(int readlimit)
    Marks the current position in this input stream.
    boolean
    markSupported()
    Tests if this input stream supports the mark and reset methods.

    Methods declared in class InputStream

    nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo
    Modifier and Type
    Method
    Description
    static InputStream
    nullInputStream()
    Returns a new InputStream that reads no bytes.
    byte[]
    readAllBytes()
    Reads all remaining bytes from the input stream.
    int
    readNBytes(byte[] b, int off, int len)
    Reads the requested number of bytes from the input stream into the given byte array.
    byte[]
    readNBytes(int len)
    Reads up to a specified number of bytes from the input stream.
    void
    skipNBytes(long n)
    Skips over and discards exactly n bytes of data from this input stream.
    long
    transferTo(OutputStream out)
    Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • ProgressMonitorInputStream

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

    • 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:

    • 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 array b at which the data is written.
      len - the maximum number of bytes to 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:

    • 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:

    • 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:

    • 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 this stream has not been marked or if the mark has been invalidated.
      See Also: