org.apache.commons.io.input

Class MessageDigestCalculatingInputStream

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.MessageDigestCalculatingInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class MessageDigestCalculatingInputStream
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 an MD5 sum.

To build an instance, see MessageDigestCalculatingInputStream.Builder.

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

Note: Neither ObservableInputStream, nor MessageDigest, are thread safe. So is MessageDigestCalculatingInputStream.

TODO Rename to MessageDigestInputStream in 3.0.

Nested Class Summary

Nested Classes

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

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

ObservableInputStream.Observer

Constructor Summary

Constructors

Constructor and Description
MessageDigestCalculatingInputStream(java.io.InputStream inputStream) Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().
MessageDigestCalculatingInputStream(java.io.InputStream inputStream, java.security.MessageDigest messageDigest) Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().
MessageDigestCalculatingInputStream(java.io.InputStream inputStream, java.lang.String algorithm) Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().

Method Summary

Modifier and Type	Method and Description
static MessageDigestCalculatingInputStream.Builder	builder() Constructs a new MessageDigestCalculatingInputStream.Builder.
java.security.MessageDigest	getMessageDigest() Gets the MessageDigest, which is being used for generating the checksum.

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

add, close, consume, getObservers, read, read, read, remove, removeAllObservers

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

available, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageDigestCalculatingInputStream

@Deprecated
public MessageDigestCalculatingInputStream(java.io.InputStream inputStream)
                                                throws java.security.NoSuchAlgorithmException

Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().

Creates a new instance, which calculates a signature on the given stream, using a MessageDigest with the "MD5" algorithm.

The MD5 algorithm is weak and should not be used.

Parameters:

inputStream - the stream to calculate the message digest for

Throws:

java.security.NoSuchAlgorithmException - if no Provider supports a MessageDigestSpi implementation for the specified algorithm.

MessageDigestCalculatingInputStream

@Deprecated
public MessageDigestCalculatingInputStream(java.io.InputStream inputStream,
                                                       java.security.MessageDigest messageDigest)

Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().

Creates a new instance, which calculates a signature on the given stream, using the given MessageDigest.

Parameters:

inputStream - the stream to calculate the message digest for

messageDigest - the message digest to use

MessageDigestCalculatingInputStream

@Deprecated
public MessageDigestCalculatingInputStream(java.io.InputStream inputStream,
                                                       java.lang.String algorithm)
                                                throws java.security.NoSuchAlgorithmException

Deprecated. Use builder(), MessageDigestCalculatingInputStream.Builder, and MessageDigestCalculatingInputStream.Builder.get().

Creates a new instance, which calculates a signature on the given stream, using a MessageDigest with the given algorithm.

Parameters:

inputStream - the stream to calculate the message digest for

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

Throws:

java.security.NoSuchAlgorithmException - if no Provider supports a MessageDigestSpi implementation for the specified algorithm.

Method Detail

builder

public static MessageDigestCalculatingInputStream.Builder builder()

Constructs a new MessageDigestCalculatingInputStream.Builder.

Returns:

a new MessageDigestCalculatingInputStream.Builder.

Since:

2.12.0

getMessageDigest

public java.security.MessageDigest getMessageDigest()

Gets the MessageDigest, which is being used for generating the checksum.

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