Package org.apache.commons.io.input

Class MessageDigestInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.commons.io.input.ProxyInputStream

org.apache.commons.io.input.ObservableInputStream

org.apache.commons.io.input.MessageDigestInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public final class MessageDigestInputStream
extends ObservableInputStream

This class is an example for using an ObservableInputStream. It creates its own ObservableInputStream.Observer, which calculates a checksum using a MessageDigest, for example, a SHA-512 sum.

To build an instance, use MessageDigestInputStream.Builder.

See the MessageDigest section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.

You must specify a message digest algorithm name or instance.

Note: Neither ObservableInputStream, nor MessageDigest, are thread safe, so is MessageDigestInputStream.

Since:

2.15.0

See Also:

• MessageDigestInputStream.Builder

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MessageDigestInputStream.Builder	Builds new MessageDigestInputStream.
static class	MessageDigestInputStream.MessageDigestMaintainingObserver	Maintains the message digest.

Nested classes/interfaces inherited from class org.apache.commons.io.input.ObservableInputStream

ObservableInputStream.AbstractBuilder<T extends ObservableInputStream.AbstractBuilder<T>>, ObservableInputStream.Observer

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Method Summary

Modifier and Type	Method	Description
static MessageDigestInputStream.Builder	builder()	Constructs a new MessageDigestInputStream.Builder.
MessageDigest	getMessageDigest()	Gets the MessageDigest, which is being used for generating the checksum, never null.

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

add, close, consume, getObservers, noteClosed, noteDataByte, noteDataBytes, noteError, noteFinished, read, read, read, remove, removeAllObservers

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

afterRead, available, beforeRead, handleIOException, mark, markSupported, reset, skip, unwrap

Methods inherited from class java.lang.Object

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

Method Details

builder

public static MessageDigestInputStream.Builder builder()

Constructs a new MessageDigestInputStream.Builder.

Returns:

a new MessageDigestInputStream.Builder.

getMessageDigest

public MessageDigest getMessageDigest()

Gets the MessageDigest, which is being used for generating the checksum, never null.

Note: The checksum will only reflect the data, which has been read so far. This is probably not, what you expect. Make sure, that the complete data has been read, if that is what you want. The easiest way to do so is by invoking ObservableInputStream.consume().

Returns:

the message digest used, never null.