com.amazonaws.http

Class HttpMethodReleaseInputStream

java.lang.Object

java.io.InputStream

com.amazonaws.internal.SdkInputStream

com.amazonaws.http.HttpMethodReleaseInputStream

All Implemented Interfaces:

MetricAware, java.io.Closeable, java.lang.AutoCloseable

public class HttpMethodReleaseInputStream
extends SdkInputStream

Utility class to wrap InputStreams obtained from an HttpClient library's HttpMethod object, and ensure the stream and HTTP connection are properly released.

This input stream wrapper is used to ensure that input streams obtained through HttpClient connections are cleaned up correctly once the caller has read all the contents of the connection's input stream, or closed the input stream. Additionally, this class attempts to release the connection and close the stream in this object's finalizer method, as a last resort to avoid leaking resources.

Important! This input stream must be completely consumed or closed to ensure the necessary cleanup operations can be performed.

Constructor Summary

Constructors

Constructor and Description
HttpMethodReleaseInputStream(org.apache.http.HttpEntityEnclosingRequest httpMethod) Constructs an input stream based on an HttpMethod object representing an HTTP connection.

Method Summary

Methods

Modifier and Type	Method and Description
int	available() Standard input stream available method, except it ensures that releaseConnection() is called if any errors are encountered from the wrapped stream.
void	close() Standard input stream close method, except it ensures that releaseConnection() is called before the input stream is closed.
protected void	finalize() Tries to ensure a connection is always cleaned-up correctly by calling releaseConnection() on class destruction if the cleanup hasn't already been done.
org.apache.http.HttpEntityEnclosingRequest	getHttpRequest() Returns the underlying HttpMethod object that contains/manages the actual HTTP connection.
protected java.io.InputStream	getWrappedInputStream() Returns the underlying input stream, if any, from the subclass; or null if there is no underlying input stream.
int	read() Standard input stream read method, except it calls releaseConnection() when the underlying input stream is consumed.
int	read(byte[] b, int off, int len) Standard input stream read method, except it calls releaseConnection() when the underlying input stream is consumed.
protected void	releaseConnection() Forces the release of an HttpMethod's connection in a way that will perform all the necessary cleanup through the correct use of HttpClient methods.

Methods inherited from class com.amazonaws.internal.SdkInputStream

abort, abortIfNeeded, isMetricActivated

Methods inherited from class java.io.InputStream

mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

HttpMethodReleaseInputStream

public HttpMethodReleaseInputStream(org.apache.http.HttpEntityEnclosingRequest httpMethod)

Constructs an input stream based on an HttpMethod object representing an HTTP connection. If a connection input stream is available, this constructor wraps the underlying input stream and makes that stream available. If no underlying connection is available, an empty ByteArrayInputStream is made available.

Parameters:

httpMethod - The HTTP method being executed, whose response content is to be wrapped.

Method Detail

getHttpRequest

public org.apache.http.HttpEntityEnclosingRequest getHttpRequest()

Returns the underlying HttpMethod object that contains/manages the actual HTTP connection.

Returns:

the HTTPMethod object that provides the data input stream.

releaseConnection

protected void releaseConnection()
                          throws java.io.IOException

Forces the release of an HttpMethod's connection in a way that will perform all the necessary cleanup through the correct use of HttpClient methods.

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Standard input stream read method, except it calls releaseConnection() when the underlying input stream is consumed.

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.read()

read

public int read(byte[] b,
       int off,
       int len)
         throws java.io.IOException

Standard input stream read method, except it calls releaseConnection() when the underlying input stream is consumed.

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.read(byte[], int, int)

available

public int available()
              throws java.io.IOException

Standard input stream available method, except it ensures that releaseConnection() is called if any errors are encountered from the wrapped stream.

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.available()

close

public void close()
           throws java.io.IOException

Standard input stream close method, except it ensures that releaseConnection() is called before the input stream is closed.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

See Also:

InputStream.close()

finalize

protected void finalize()
                 throws java.lang.Throwable

Tries to ensure a connection is always cleaned-up correctly by calling releaseConnection() on class destruction if the cleanup hasn't already been done.

This desperate cleanup act will only be necessary if the user of this class does not completely consume or close this input stream prior to object destruction. This method will log Warning messages if a forced cleanup is required, hopefully reminding the user to close their streams properly.

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

getWrappedInputStream

protected java.io.InputStream getWrappedInputStream()

Description copied from class: SdkInputStream

Returns the underlying input stream, if any, from the subclass; or null if there is no underlying input stream.

Specified by:

getWrappedInputStream in class SdkInputStream