java.util.zip
Class CheckedInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          java.util.zip.CheckedInputStream

public class CheckedInputStream

extends FilterInputStream

An input stream that also maintains a checksum of the data being read. The checksum can then be used to verify the integrity of the input data.

Author:

David Connelly

See Also:

Checksum

Field Summary

private Checksum

cksum

Fields inherited from class java.io.FilterInputStream

in

Fields inherited from class java.io.InputStream

Constructor Summary

CheckedInputStream(InputStream in, Checksum cksum)
Creates an input stream using the specified Checksum.

Method Summary

Checksum	getChecksum() Returns the Checksum for this input stream.
int	read() Reads a byte.
int	read(byte[] buf, int off, int len) Reads into an array of bytes.
long	skip(long n) Skips specified number of bytes of input.

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, reset

Methods inherited from class java.lang.Object

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

Field Detail

cksum

private Checksum cksum

Constructor Detail

CheckedInputStream

public CheckedInputStream(InputStream in,
                          Checksum cksum)

Creates an input stream using the specified Checksum.

Parameters:

in - the input stream

cksum - the Checksum

Method Detail

read

public int read()
         throws IOException

Reads a byte. Will block if no input is available.

Overrides:

read in class FilterInputStream

Returns:

the byte read, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error has occurred

See Also:

FilterInputStream.in

read

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

Reads into an array of bytes. Will block until some input is available.

Overrides:

read in class FilterInputStream

Parameters:

buf - the buffer into which the data is read

off - the start offset of the data

len - the maximum number of bytes read

Returns:

the actual number of bytes read, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error has occurred

See Also:

FilterInputStream.in

skip

public long skip(long n)
          throws IOException

Skips specified number of bytes of input.

Overrides:

skip in class FilterInputStream

Parameters:

n - the number of bytes to skip

Returns:

the actual number of bytes skipped

Throws:

IOException - if an I/O error has occurred

getChecksum

public Checksum getChecksum()

Returns the Checksum for this input stream.

Returns:

the Checksum value