Package org.apache.commons.io.input

Class ChecksumInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.commons.io.input.ProxyInputStream

org.apache.commons.io.input.CountingInputStream

org.apache.commons.io.input.ChecksumInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public final class ChecksumInputStream
extends CountingInputStream

Automatically verifies a Checksum value once the stream is exhausted or the count threshold is reached.

If the Checksum does not meet the expected value when exhausted, then the input stream throws an IOException.

If you do not need the verification or threshold feature, then use a plain CheckedInputStream.

To build an instance, use ChecksumInputStream.Builder.

Since:

2.16.0

See Also:

• ChecksumInputStream.Builder

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ChecksumInputStream.Builder	Builds a new ChecksumInputStream.

Field Summary

Fields

Modifier and Type	Field	Description
private final long	countThreshold	The count threshold to limit how much input is consumed to update the Checksum before the input stream validates its value.
private final long	expectedChecksumValue	The expected checksum.

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ChecksumInputStream(InputStream in, Checksum checksum, long expectedChecksumValue, long countThreshold)	Constructs a new instance.

Method Summary

Modifier and Type	Method	Description
protected void	afterRead(int n)	Adds the number of read bytes to the count.
static ChecksumInputStream.Builder	builder()	Constructs a new ChecksumInputStream.Builder.
private Checksum	getChecksum()	Gets the current checksum value.
long	getRemaining()	Gets the byte count remaining to read.

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

getByteCount, getCount, resetByteCount, resetCount, skip

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

available, beforeRead, close, handleIOException, mark, markSupported, read, read, read, reset, unwrap

Methods inherited from class java.lang.Object

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

Field Details

expectedChecksumValue

private final long expectedChecksumValue

The expected checksum.

countThreshold

private final long countThreshold

The count threshold to limit how much input is consumed to update the Checksum before the input stream validates its value.

By default, all input updates the Checksum.

Constructor Details

ChecksumInputStream

private ChecksumInputStream(InputStream in,
 Checksum checksum,
 long expectedChecksumValue,
 long countThreshold)

Constructs a new instance.

Parameters:

in - the stream to wrap.

checksum - a Checksum implementation.

expectedChecksumValue - the expected checksum.

countThreshold - the count threshold to limit how much input is consumed, a negative number means the threshold is unbound.

Method Details

builder

public static ChecksumInputStream.Builder builder()

Constructs a new ChecksumInputStream.Builder.

Returns:

a new ChecksumInputStream.Builder.

afterRead

protected void afterRead(int n)
                  throws IOException

Description copied from class: CountingInputStream

Adds the number of read bytes to the count.

Overrides:

afterRead in class CountingInputStream

Parameters:

n - number of bytes read, or -1 if no more bytes are available

Throws:

IOException - Not thrown here but subclasses may throw.

getChecksum

private Checksum getChecksum()

Gets the current checksum value.

Returns:

the current checksum value.

getRemaining

public long getRemaining()

Gets the byte count remaining to read.

Returns:

bytes remaining to read, a negative number means the threshold is unbound.