- java.lang.Object
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- java.io.Reader
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- java.io.FilterReader
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- All Implemented Interfaces:
Closeable,AutoCloseable,Readable
- Direct Known Subclasses:
PushbackReader
public abstract class FilterReader extends Reader
Abstract class for reading filtered character streams. The abstract classFilterReaderitself provides default methods that pass all requests to the contained stream. Subclasses ofFilterReadershould override some of these methods and may also provide additional methods and fields.- Since:
- 1.1
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Constructor Summary
Constructors Modifier Constructor Description protectedFilterReader(Reader in)Creates a new filtered reader.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidmark(int readAheadLimit)Marks the present position in the stream.booleanmarkSupported()Tells whether this stream supports the mark() operation.intread()Reads a single character.intread(char[] cbuf, int off, int len)Reads characters into a portion of an array.booleanready()Tells whether this stream is ready to be read.voidreset()Resets the stream.longskip(long n)Skips characters.-
Methods declared in class java.io.Reader
close, nullReader, read, read, transferTo
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Field Detail
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in
protected Reader in
The underlying character-input stream.
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Constructor Detail
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FilterReader
protected FilterReader(Reader in)
Creates a new filtered reader.- Parameters:
in- a Reader object providing the underlying stream.- Throws:
NullPointerException- ifinisnull
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Method Detail
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read
public int read() throws IOExceptionReads a single character.- Overrides:
readin classReader- Returns:
- The character read, as an integer in the range 0 to 65535
(
0x00-0xffff), or -1 if the end of the stream has been reached - Throws:
IOException- If an I/O error occurs
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read
public int read(char[] cbuf, int off, int len) throws IOExceptionReads characters into a portion of an array.- Specified by:
readin classReader- Parameters:
cbuf- Destination bufferoff- Offset at which to start storing characterslen- Maximum number of characters to read- Returns:
- The number of characters read, or -1 if the end of the stream has been reached
- Throws:
IOException- If an I/O error occursIndexOutOfBoundsException- If an I/O error occurs
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skip
public long skip(long n) throws IOExceptionSkips characters.- Overrides:
skipin classReader- Parameters:
n- The number of characters to skip- Returns:
- The number of characters actually skipped
- Throws:
IOException- If an I/O error occurs
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ready
public boolean ready() throws IOExceptionTells whether this stream is ready to be read.- Overrides:
readyin classReader- Returns:
- True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
- Throws:
IOException- If an I/O error occurs
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markSupported
public boolean markSupported()
Tells whether this stream supports the mark() operation.- Overrides:
markSupportedin classReader- Returns:
- true if and only if this stream supports the mark operation.
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mark
public void mark(int readAheadLimit) throws IOExceptionMarks the present position in the stream.- Overrides:
markin classReader- Parameters:
readAheadLimit- Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.- Throws:
IOException- If an I/O error occurs
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reset
public void reset() throws IOExceptionResets the stream.- Overrides:
resetin classReader- Throws:
IOException- If an I/O error occurs
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