org.apache.commons.io.input
Class CountingInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          org.apache.commons.io.input.ProxyInputStream
              org.apache.commons.io.input.CountingInputStream

All Implemented Interfaces:

Closeable

public class CountingInputStream
extends ProxyInputStream

A decorating input stream that counts the number of bytes that have passed through the stream so far.

A typical use case would be during debugging, to ensure that data is being read as expected.

Version:

$Id: CountingInputStream.java 471628 2006-11-06 04:06:45Z bayard $

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

CountingInputStream(InputStream in)
Constructs a new CountingInputStream.

Method Summary

long	getByteCount() The number of bytes that have passed through this stream.
int	getCount() The number of bytes that have passed through this stream.
int	read() Reads the next byte of data adding to the count of bytes received if a byte is successfully read.
int	read(byte[] b) Reads a number of bytes into the byte array, keeping count of the number read.
int	read(byte[] b, int off, int len) Reads a number of bytes into the byte array at a specific offset, keeping count of the number read.
long	resetByteCount() Set the byte count back to 0.
int	resetCount() Set the byte count back to 0.
long	skip(long length) Skips the stream over the specified number of bytes, adding the skipped amount to the count.

Methods inherited from class org.apache.commons.io.input.ProxyInputStream

available, close, mark, markSupported, reset

Methods inherited from class java.lang.Object

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

Constructor Detail

CountingInputStream

public CountingInputStream(InputStream in)

Constructs a new CountingInputStream.

Parameters:

in - the InputStream to delegate to

Method Detail

read

public int read(byte[] b)
         throws IOException

Reads a number of bytes into the byte array, keeping count of the number read.

Overrides:

read in class ProxyInputStream

Parameters:

b - the buffer into which the data is read, not null

Returns:

the total number of bytes read into the buffer, -1 if end of stream

Throws:

IOException - if an I/O error occurs

See Also:

InputStream.read(byte[])

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Reads a number of bytes into the byte array at a specific offset, keeping count of the number read.

Overrides:

read in class ProxyInputStream

Parameters:

b - the buffer into which the data is read, not null

off - the start offset in the buffer

len - the maximum number of bytes to read

Returns:

the total number of bytes read into the buffer, -1 if end of stream

Throws:

IOException - if an I/O error occurs

See Also:

InputStream.read(byte[], int, int)

read

public int read()
         throws IOException

Reads the next byte of data adding to the count of bytes received if a byte is successfully read.

Overrides:

read in class ProxyInputStream

Returns:

the byte read, -1 if end of stream

Throws:

IOException - if an I/O error occurs

See Also:

InputStream.read()

skip

public long skip(long length)
          throws IOException

Skips the stream over the specified number of bytes, adding the skipped amount to the count.

Overrides:

skip in class ProxyInputStream

Parameters:

length - the number of bytes to skip

Returns:

the actual number of bytes skipped

Throws:

IOException - if an I/O error occurs

See Also:

InputStream.skip(long)

getCount

public int getCount()

The number of bytes that have passed through this stream.

NOTE: From v1.3 this method throws an ArithmeticException if the count is greater than can be expressed by an int. See getByteCount() for a method using a long.

Returns:

the number of bytes accumulated

Throws:

ArithmeticException - if the byte count is too large

resetCount

public int resetCount()

Set the byte count back to 0.

NOTE: From v1.3 this method throws an ArithmeticException if the count is greater than can be expressed by an int. See resetByteCount() for a method using a long.

Returns:

the count previous to resetting

Throws:

ArithmeticException - if the byte count is too large

getByteCount

public long getByteCount()

The number of bytes that have passed through this stream.

NOTE: This method is an alternative for getCount() and was added because that method returns an integer which will result in incorrect count for files over 2GB.

Returns:

the number of bytes accumulated

Since:

Commons IO 1.3

resetByteCount

public long resetByteCount()

Set the byte count back to 0.

NOTE: This method is an alternative for resetCount() and was added because that method returns an integer which will result in incorrect count for files over 2GB.

Returns:

the count previous to resetting

Since:

Commons IO 1.3