Class ProxyInputStream
- All Implemented Interfaces:
Closeable
,AutoCloseable
- Direct Known Subclasses:
AutoCloseInputStream
,BOMInputStream
,CloseShieldInputStream
,CountingInputStream
,MarkShieldInputStream
,ObservableInputStream
,SwappedDataInputStream
,TaggedInputStream
,TeeInputStream
It is an alternative base class to FilterInputStream to increase reusability, because FilterInputStream changes the methods being called, such as read(byte[]) to read(byte[], int, int).
See the protected methods for ways in which a subclass can easily decorate a stream with custom pre-, post- or error processing functionality.
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Field Summary
Fields inherited from class java.io.FilterInputStream
in
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
afterRead
(int n) Invoked by the read methods after the proxied call has returned successfully.int
Invokes the delegate'savailable()
method.protected void
beforeRead
(int n) Invoked by the read methods before the call is proxied.void
close()
Invokes the delegate'sclose()
method.protected void
Handle any IOExceptions thrown; by default, throws the given exception.void
mark
(int readLimit) Invokes the delegate'smark(int)
method.boolean
Invokes the delegate'smarkSupported()
method.int
read()
Invokes the delegate'sread()
method.int
read
(byte[] bts) Invokes the delegate'sread(byte[])
method.int
read
(byte[] bts, int off, int len) Invokes the delegate'sread(byte[], int, int)
method.void
reset()
Invokes the delegate'sreset()
method.long
skip
(long ln) Invokes the delegate'sskip(long)
method.
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Constructor Details
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ProxyInputStream
Constructs a new ProxyInputStream.- Parameters:
proxy
- the InputStream to delegate to
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Method Details
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afterRead
Invoked by the read methods after the proxied call has returned successfully. The number of bytes returned to the caller (or -1 if the end of stream was reached) is given as an argument.Subclasses can override this method to add common post-processing functionality without having to override all the read methods. The default implementation does nothing.
Note this method is not called from
skip(long)
orreset()
. You need to explicitly override those methods if you want to add post-processing steps also to them.- Parameters:
n
- number of bytes read, or -1 if the end of stream was reached- Throws:
IOException
- if the post-processing fails- Since:
- 2.0
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available
Invokes the delegate'savailable()
method.- Overrides:
available
in classFilterInputStream
- Returns:
- the number of available bytes
- Throws:
IOException
- if an I/O error occurs.
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beforeRead
Invoked by the read methods before the call is proxied. The number of bytes that the caller wanted to read (1 for theread()
method, buffer length forread(byte[])
, etc.) is given as an argument.Subclasses can override this method to add common pre-processing functionality without having to override all the read methods. The default implementation does nothing.
Note this method is not called from
skip(long)
orreset()
. You need to explicitly override those methods if you want to add pre-processing steps also to them.- Parameters:
n
- number of bytes that the caller asked to be read- Throws:
IOException
- if the pre-processing fails- Since:
- 2.0
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close
Invokes the delegate'sclose()
method.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classFilterInputStream
- Throws:
IOException
- if an I/O error occurs.
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handleIOException
Handle any IOExceptions thrown; by default, throws the given exception.This method provides a point to implement custom exception handling. The default behavior is to re-throw the exception.
- Parameters:
e
- The IOException thrown- Throws:
IOException
- if an I/O error occurs.- Since:
- 2.0
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mark
Invokes the delegate'smark(int)
method.- Overrides:
mark
in classFilterInputStream
- Parameters:
readLimit
- read ahead limit
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markSupported
Invokes the delegate'smarkSupported()
method.- Overrides:
markSupported
in classFilterInputStream
- Returns:
- true if mark is supported, otherwise false
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read
Invokes the delegate'sread()
method.- Overrides:
read
in classFilterInputStream
- Returns:
- the byte read or -1 if the end of stream
- Throws:
IOException
- if an I/O error occurs.
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read
Invokes the delegate'sread(byte[])
method.- Overrides:
read
in classFilterInputStream
- Parameters:
bts
- the buffer to read the bytes into- Returns:
- the number of bytes read or EOF if the end of stream
- Throws:
IOException
- if an I/O error occurs.
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read
Invokes the delegate'sread(byte[], int, int)
method.- Overrides:
read
in classFilterInputStream
- Parameters:
bts
- the buffer to read the bytes intooff
- The start offsetlen
- The number of bytes to read- Returns:
- the number of bytes read or -1 if the end of stream
- Throws:
IOException
- if an I/O error occurs.
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reset
Invokes the delegate'sreset()
method.- Overrides:
reset
in classFilterInputStream
- Throws:
IOException
- if an I/O error occurs.
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skip
Invokes the delegate'sskip(long)
method.- Overrides:
skip
in classFilterInputStream
- Parameters:
ln
- the number of bytes to skip- Returns:
- the actual number of bytes skipped
- Throws:
IOException
- if an I/O error occurs.
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