Package 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:
Closeable
,AutoCloseable
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.
Note: Neither ObservableInputStream
, nor MessageDigest
,
are thread safe. So is MessageDigestCalculatingInputStream
.-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
Maintains the message digest.Nested classes/interfaces inherited from class org.apache.commons.io.input.ObservableInputStream
ObservableInputStream.Observer
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Field Summary
FieldsFields inherited from class java.io.FilterInputStream
in
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Constructor Summary
ConstructorsConstructorDescriptionMessageDigestCalculatingInputStream
(InputStream inputStream) Creates a new instance, which calculates a signature on the given stream, using aMessageDigest
with the "MD5" algorithm.MessageDigestCalculatingInputStream
(InputStream inputStream, String algorithm) Creates a new instance, which calculates a signature on the given stream, using aMessageDigest
with the given algorithm.MessageDigestCalculatingInputStream
(InputStream inputStream, MessageDigest MessageDigest) Creates a new instance, which calculates a signature on the given stream, using the givenMessageDigest
. -
Method Summary
Modifier and TypeMethodDescriptionReturns theMessageDigest
, which is being used for generating the checksum.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
Methods inherited from class java.io.InputStream
nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo
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Field Details
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messageDigest
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Constructor Details
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MessageDigestCalculatingInputStream
Creates a new instance, which calculates a signature on the given stream, using the givenMessageDigest
.- Parameters:
inputStream
- the stream to calculate the message digest forMessageDigest
- the message digest to use
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MessageDigestCalculatingInputStream
public MessageDigestCalculatingInputStream(InputStream inputStream, String algorithm) throws NoSuchAlgorithmException Creates a new instance, which calculates a signature on the given stream, using aMessageDigest
with the given algorithm.- Parameters:
inputStream
- the stream to calculate the message digest foralgorithm
- the name of the algorithm to use- Throws:
NoSuchAlgorithmException
- if no Provider supports a MessageDigestSpi implementation for the specified algorithm.
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MessageDigestCalculatingInputStream
Creates a new instance, which calculates a signature on the given stream, using aMessageDigest
with the "MD5" algorithm.- Parameters:
inputStream
- the stream to calculate the message digest for- Throws:
NoSuchAlgorithmException
- if no Provider supports a MessageDigestSpi implementation for the specified algorithm.
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Method Details
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getMessageDigest
Returns theMessageDigest
, 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 invokingObservableInputStream.consume()
.- Returns:
- the message digest used
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