com.amazonaws.internal

Class SdkDigestInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.security.DigestInputStream

com.amazonaws.internal.SdkDigestInputStream

All Implemented Interfaces:

MetricAware, Releasable, Closeable, AutoCloseable

public class SdkDigestInputStream
extends DigestInputStream
implements MetricAware, Releasable

Base class for AWS Java SDK specific DigestInputStream.

Field Summary

Fields inherited from class java.security.DigestInputStream

digest

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor and Description
SdkDigestInputStream(InputStream stream, MessageDigest digest)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isMetricActivated() Returns true if this object or one of it's inner wrapped objects has metrics gathering activity turned on; false otherwise.
void	release() Releases the allocated resource.
long	skip(long n) Skips over and discards n bytes of data from this input stream, while taking the skipped bytes into account for digest calculation.

Methods inherited from class java.security.DigestInputStream

getMessageDigest, on, read, read, setMessageDigest, toString

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, reset

Methods inherited from class java.lang.Object

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

Constructor Detail

SdkDigestInputStream

public SdkDigestInputStream(InputStream stream,
                    MessageDigest digest)

Method Detail

isMetricActivated

public final boolean isMetricActivated()

Description copied from interface: MetricAware

Returns true if this object or one of it's inner wrapped objects has metrics gathering activity turned on; false otherwise.

Specified by:

isMetricActivated in interface MetricAware

skip

public final long skip(long n)
                throws IOException

Skips over and discards n bytes of data from this input stream, while taking the skipped bytes into account for digest calculation. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

The skip method of this class creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method. For instance, the implementation may depend on the ability to seek.

Overrides:

skip in class FilterInputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

IOException - if the stream does not support seek, or if some other I/O error occurs.

release

public final void release()

Description copied from interface: Releasable

Releases the allocated resource. This method should not be called except by the caller who allocated the resource at the very top of the call stack. This allows, typically, a Closeable resource to be not unintentionally released owing to the calling of the Closeable.close() methods by implementation deep down in the call stack.

For example, the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

Specified by:

release in interface Releasable