com.compomics.util.io
Class MonitorableFileInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by java.io.FilterInputStream
          extended by com.compomics.util.io.MonitorableInputStream
              extended by com.compomics.util.io.MonitorableFileInputStream
All Implemented Interfaces:
Monitorable, java.io.Closeable

public class MonitorableFileInputStream
extends MonitorableInputStream

This class implements an InputStream that reports on the progress of reading a file in integer quantities, even though the underlying file may have a binary size that is outside of integer range.

Author:
Lennart Martens

Field Summary
 
Fields inherited from class java.io.FilterInputStream
in
 
Constructor Summary
MonitorableFileInputStream(java.io.File aFile)
          This constructor takes a file to load the FileInputStream from.
MonitorableFileInputStream(java.lang.String aFile)
          This constructor takes a file to load the FileInputStream from.
 
Method Summary
 int getMaximum()
          This method reports on the maximum scale for the monitor.
 int monitorProgress()
          This method returns the progress (as measured by taking the value of iMaximum, minus the current progress as reported by the cache).
 int read()
          Reads the next byte of data from this input stream.
 int read(byte[] b)
          Reads up to byte.length bytes of data from this input stream into an array of bytes.
 int read(byte[] b, int off, int len)
          Reads up to len bytes of data from this input stream into an array of bytes.
 void reset()
          Repositions this stream to the position at the time the mark method was last called on this input stream.
 long skip(long n)
          Skips over and discards n bytes of data from the input stream.
 
Methods inherited from class java.io.FilterInputStream
available, close, mark, markSupported
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MonitorableFileInputStream

public MonitorableFileInputStream(java.io.File aFile)
                           throws java.io.IOException
This constructor takes a file to load the FileInputStream from.

Parameters:
aFile - File to connect the inputstream to.
Throws:
java.io.IOException - when the file could not be raed.

MonitorableFileInputStream

public MonitorableFileInputStream(java.lang.String aFile)
                           throws java.io.IOException
This constructor takes a file to load the FileInputStream from.

Parameters:
aFile - String with the filename for the file to connect the inputstream to.
Throws:
java.io.IOException - when the file could not be raed.
Method Detail

getMaximum

public int getMaximum()
This method reports on the maximum scale for the monitor.

Specified by:
getMaximum in interface Monitorable
Overrides:
getMaximum in class MonitorableInputStream
Returns:
int with the maximum for the monitor.

monitorProgress

public int monitorProgress()
This method returns the progress (as measured by taking the value of iMaximum, minus the current progress as reported by the cache).

Specified by:
monitorProgress in interface Monitorable
Overrides:
monitorProgress in class MonitorableInputStream
Returns:
int with the progress.

read

public int read(byte[] b)
         throws java.io.IOException
Reads up to byte.length bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

This method simply performs the call read(b, 0, b.length) and returns the result. It is important that it does not do in.read(b) instead; certain subclasses of FilterInputStream depend on the implementation strategy actually used.

Overrides:
read in class MonitorableInputStream
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:
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.read(byte[], int, int)

read

public int read()
         throws java.io.IOException
Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

This method simply performs in.read() and returns the result.

Overrides:
read in class MonitorableInputStream
Returns:
the next byte of data, or -1 if the end of the stream is reached.
Throws:
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

This method simply performs in.read(b, off, len) and returns the result.

Overrides:
read in class MonitorableInputStream
Parameters:
b - the buffer into which the data is read.
off - the start offset of the data.
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:
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in

skip

public long skip(long n)
          throws java.io.IOException
Skips over and discards n bytes of data from the input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. The actual number of bytes skipped is returned.

This method simply performs in.skip(n).

Overrides:
skip in class MonitorableInputStream
Parameters:
n - the number of bytes to be skipped.
Returns:
the actual number of bytes skipped.
Throws:
java.io.IOException - if an I/O error occurs.

reset

public void reset()
           throws java.io.IOException
Repositions this stream to the position at the time the mark method was last called on this input stream.

This method simply performs in.reset().

Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parse, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If this happens within readlimit bytes, it allows the outer code to reset the stream and try another parser.

Overrides:
reset in class MonitorableInputStream
Throws:
java.io.IOException - if the stream has not been marked or if the mark has been invalidated.
See Also:
FilterInputStream.in, FilterInputStream.mark(int)


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