Package org.apache.commons.io.input
Class ObservableInputStream
- java.lang.Object
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- java.io.InputStream
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- java.io.FilterInputStream
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- org.apache.commons.io.input.ProxyInputStream
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- org.apache.commons.io.input.ObservableInputStream
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
- Direct Known Subclasses:
MessageDigestCalculatingInputStream
public class ObservableInputStream extends ProxyInputStream
TheObservableInputStream
allows, that an InputStream may be consumed by other receivers, apart from the thread, which is reading it. The other consumers are implemented as instances ofObservableInputStream.Observer
. A typical application may be the generation of aMessageDigest
on the fly.Note
: TheObservableInputStream
is not thread safe, as instances of InputStream usually aren't. If you must access the stream from multiple threads, then synchronization, locking, or a similar means must be used.- See Also:
MessageDigestCalculatingInputStream
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ObservableInputStream.Observer
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Constructor Summary
Constructors Constructor Description ObservableInputStream(java.io.InputStream pProxy)
Creates a new ObservableInputStream for the given InputStream.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
add(ObservableInputStream.Observer pObserver)
Adds an Observer.void
close()
Invokes the delegate'sclose()
method.void
consume()
Reads all data from the underlyingInputStream
, while notifying the observers.protected java.util.List<ObservableInputStream.Observer>
getObservers()
Gets all currently registered observers.protected void
noteClosed()
Notifies the observers by invokingObservableInputStream.Observer.finished()
.protected void
noteDataByte(int pDataByte)
Notifies the observers by invokingObservableInputStream.Observer.data(int)
with the given arguments.protected void
noteDataBytes(byte[] pBuffer, int pOffset, int pLength)
Notifies the observers by invokingObservableInputStream.Observer.data(byte[],int,int)
with the given arguments.protected void
noteError(java.io.IOException pException)
Notifies the observers by invokingObservableInputStream.Observer.error(IOException)
with the given argument.protected void
noteFinished()
Notifies the observers by invokingObservableInputStream.Observer.finished()
.int
read()
Invokes the delegate'sread()
method.int
read(byte[] pBuffer)
Invokes the delegate'sread(byte[])
method.int
read(byte[] pBuffer, int pOffset, int pLength)
Invokes the delegate'sread(byte[], int, int)
method.void
remove(ObservableInputStream.Observer pObserver)
Removes an Observer.void
removeAllObservers()
Removes all Observers.-
Methods inherited from class org.apache.commons.io.input.ProxyInputStream
afterRead, available, beforeRead, handleIOException, mark, markSupported, reset, skip
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Method Detail
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add
public void add(ObservableInputStream.Observer pObserver)
Adds an Observer.- Parameters:
pObserver
- the observer to add
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remove
public void remove(ObservableInputStream.Observer pObserver)
Removes an Observer.- Parameters:
pObserver
- the observer to remove
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removeAllObservers
public void removeAllObservers()
Removes all Observers.
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read
public int read() throws java.io.IOException
Description copied from class:ProxyInputStream
Invokes the delegate'sread()
method.- Overrides:
read
in classProxyInputStream
- Returns:
- the byte read or -1 if the end of stream
- Throws:
java.io.IOException
- if an I/O error occurs
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read
public int read(byte[] pBuffer) throws java.io.IOException
Description copied from class:ProxyInputStream
Invokes the delegate'sread(byte[])
method.- Overrides:
read
in classProxyInputStream
- Parameters:
pBuffer
- the buffer to read the bytes into- Returns:
- the number of bytes read or EOF if the end of stream
- Throws:
java.io.IOException
- if an I/O error occurs
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read
public int read(byte[] pBuffer, int pOffset, int pLength) throws java.io.IOException
Description copied from class:ProxyInputStream
Invokes the delegate'sread(byte[], int, int)
method.- Overrides:
read
in classProxyInputStream
- Parameters:
pBuffer
- the buffer to read the bytes intopOffset
- The start offsetpLength
- The number of bytes to read- Returns:
- the number of bytes read or -1 if the end of stream
- Throws:
java.io.IOException
- if an I/O error occurs
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noteDataBytes
protected void noteDataBytes(byte[] pBuffer, int pOffset, int pLength) throws java.io.IOException
Notifies the observers by invokingObservableInputStream.Observer.data(byte[],int,int)
with the given arguments.- Parameters:
pBuffer
- Passed to the observers.pOffset
- Passed to the observers.pLength
- Passed to the observers.- Throws:
java.io.IOException
- Some observer has thrown an exception, which is being passed down.
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noteFinished
protected void noteFinished() throws java.io.IOException
Notifies the observers by invokingObservableInputStream.Observer.finished()
.- Throws:
java.io.IOException
- Some observer has thrown an exception, which is being passed down.
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noteDataByte
protected void noteDataByte(int pDataByte) throws java.io.IOException
Notifies the observers by invokingObservableInputStream.Observer.data(int)
with the given arguments.- Parameters:
pDataByte
- Passed to the observers.- Throws:
java.io.IOException
- Some observer has thrown an exception, which is being passed down.
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noteError
protected void noteError(java.io.IOException pException) throws java.io.IOException
Notifies the observers by invokingObservableInputStream.Observer.error(IOException)
with the given argument.- Parameters:
pException
- Passed to the observers.- Throws:
java.io.IOException
- Some observer has thrown an exception, which is being passed down. This may be the same exception, which has been passed as an argument.
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noteClosed
protected void noteClosed() throws java.io.IOException
Notifies the observers by invokingObservableInputStream.Observer.finished()
.- Throws:
java.io.IOException
- Some observer has thrown an exception, which is being passed down.
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getObservers
protected java.util.List<ObservableInputStream.Observer> getObservers()
Gets all currently registered observers.- Returns:
- a list of the currently registered observers
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close
public void close() throws java.io.IOException
Description copied from class:ProxyInputStream
Invokes the delegate'sclose()
method.- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Overrides:
close
in classProxyInputStream
- Throws:
java.io.IOException
- if an I/O error occurs
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consume
public void consume() throws java.io.IOException
Reads all data from the underlyingInputStream
, while notifying the observers.- Throws:
java.io.IOException
- The underlyingInputStream
, or either of the observers has thrown an exception.
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