Package io.ocfl.api.io

Class FixityCheckInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.security.DigestInputStream

io.ocfl.api.io.FixityCheckInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class FixityCheckInputStream
extends DigestInputStream

Wrapper around Java's DigestInputStream to compute a digest while streaming data, and then verify the fixity of the data. After all of the stream's bytes have been read, checkFixity() should be called.

Field Summary

Fields inherited from class java.security.DigestInputStream

digest

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
FixityCheckInputStream(InputStream inputStream, DigestAlgorithm digestAlgorithm, String expectedDigestValue)
FixityCheckInputStream(InputStream inputStream, String digestAlgorithm, String expectedDigestValue)

Method Summary

Modifier and Type	Method	Description
void	checkFixity()	Performs a fixity check and throws an exception if the check fails.
FixityCheckInputStream	enableFixityCheck(boolean enabled)	By default fixity checking is enabled.
Optional<String>	getActualDigestValue()	Returns the hex encoded digest value of the input stream.
String	getExpectedDigestValue()
void	on(boolean on)
String	toString()

Methods inherited from class java.security.DigestInputStream

getMessageDigest, read, read, setMessageDigest

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, reset, skip

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

Methods inherited from class java.lang.Object

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

Constructor Detail

FixityCheckInputStream

public FixityCheckInputStream(InputStream inputStream,
                              DigestAlgorithm digestAlgorithm,
                              String expectedDigestValue)

Parameters:

inputStream - the underlying stream

digestAlgorithm - the algorithm to use to calculate the digest (eg. sha512)

expectedDigestValue - the expected digest value

FixityCheckInputStream

public FixityCheckInputStream(InputStream inputStream,
                              String digestAlgorithm,
                              String expectedDigestValue)

Parameters:

inputStream - the underlying stream

digestAlgorithm - the algorithm to use to calculate the digest (eg. sha512)

expectedDigestValue - the expected digest value

Method Detail

checkFixity

public void checkFixity()

Performs a fixity check and throws an exception if the check fails. This method MUST NOT be called before the entire stream has been read, doing so will invalidate the digest.

If the check is disabled, nothing happens

Throws:

FixityCheckException - when the actual digest value does not match the expected value

getExpectedDigestValue

public String getExpectedDigestValue()

Returns:

the expected digest value

getActualDigestValue

public Optional<String> getActualDigestValue()

Returns the hex encoded digest value of the input stream. This method MUST NOT be called before the entire stream has been read, doing so will invalidate the digest. A digest will not be returned if the fixity check is disabled.

Returns:

the digest of the stream

enableFixityCheck

public FixityCheckInputStream enableFixityCheck(boolean enabled)

By default fixity checking is enabled. Use this method to disable it, and prevent needless digest computation

Parameters:

enabled - if fixity should be checked

Returns:

this stream

on

public void on(boolean on)

Overrides:

on in class DigestInputStream

toString

public String toString()

Overrides:

toString in class DigestInputStream