Class ProxyReader
- All Implemented Interfaces:
Closeable,AutoCloseable,Readable
- Direct Known Subclasses:
CloseShieldReader,TaggedReader,TeeReader
It is an alternative base class to FilterReader to increase reusability, because FilterReader changes the methods being called, such as read(char[]) to read(char[], int, int).
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Field Summary
Fields inherited from class java.io.FilterReader
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprotected voidafterRead(int n) Invoked by the read methods after the proxied call has returned successfully.protected voidbeforeRead(int n) Invoked by the read methods before the call is proxied.voidclose()Invokes the delegate'sclose()method.protected voidHandle any IOExceptions thrown.voidmark(int idx) Invokes the delegate'smark(int)method.booleanInvokes the delegate'smarkSupported()method.intread()Invokes the delegate'sread()method.intread(char[] chr) Invokes the delegate'sread(char[])method.intread(char[] chr, int st, int len) Invokes the delegate'sread(char[], int, int)method.intread(CharBuffer target) Invokes the delegate'sread(CharBuffer)method.booleanready()Invokes the delegate'sready()method.voidreset()Invokes the delegate'sreset()method.longskip(long ln) Invokes the delegate'sskip(long)method.
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Constructor Details
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ProxyReader
Constructs a new ProxyReader.- Parameters:
proxy- the Reader 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 chars 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 chars read, or -1 if the end of stream was reached- Throws:
IOException- if the post-processing fails- Since:
- 2.0
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beforeRead
Invoked by the read methods before the call is proxied. The number of chars that the caller wanted to read (1 for theread()method, buffer length forread(char[]), 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 chars 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:
closein interfaceAutoCloseable- Specified by:
closein interfaceCloseable- Overrides:
closein classFilterReader- Throws:
IOException- if an I/O error occurs.
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handleIOException
Handle any IOExceptions thrown.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:
markin classFilterReader- Parameters:
idx- read ahead limit- Throws:
IOException- if an I/O error occurs.
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markSupported
Invokes the delegate'smarkSupported()method.- Overrides:
markSupportedin classFilterReader- Returns:
- true if mark is supported, otherwise false
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read
Invokes the delegate'sread()method.- Overrides:
readin classFilterReader- Returns:
- the character 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(char[])method.- Overrides:
readin classReader- Parameters:
chr- the buffer to read the characters into- Returns:
- the number of characters 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(char[], int, int)method.- Overrides:
readin classFilterReader- Parameters:
chr- the buffer to read the characters intost- The start offsetlen- The number of bytes to read- Returns:
- the number of characters 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(CharBuffer)method.- Specified by:
readin interfaceReadable- Overrides:
readin classReader- Parameters:
target- the char buffer to read the characters into- Returns:
- the number of characters read or -1 if the end of stream
- Throws:
IOException- if an I/O error occurs.- Since:
- 2.0
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ready
Invokes the delegate'sready()method.- Overrides:
readyin classFilterReader- Returns:
- true if the stream is ready to be read
- Throws:
IOException- if an I/O error occurs.
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reset
Invokes the delegate'sreset()method.- Overrides:
resetin classFilterReader- Throws:
IOException- if an I/O error occurs.
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skip
Invokes the delegate'sskip(long)method.- Overrides:
skipin classFilterReader- Parameters:
ln- the number of bytes to skip- Returns:
- the number of bytes to skipped or EOF if the end of stream
- Throws:
IOException- if an I/O error occurs.
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