- 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 SummaryConstructors Modifier Constructor Description protectedFilterReader(Reader in)Creates a new filtered reader.
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Method SummaryAll 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.Readerclose, nullReader, read, read, transferTo
 
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Field Detail- 
inprotected Reader in The underlying character-input stream.
 
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Constructor Detail- 
FilterReaderprotected FilterReader(Reader in) Creates a new filtered reader.- Parameters:
- in- a Reader object providing the underlying stream.
- Throws:
- NullPointerException- if- inis- null
 
 
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Method Detail- 
readpublic int read() throws IOExceptionReads a single character.- Overrides:
- readin class- Reader
- 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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readpublic int read(char[] cbuf, int off, int len) throws IOExceptionReads characters into a portion of an array.- Specified by:
- readin class- Reader
- Parameters:
- cbuf- Destination buffer
- off- Offset at which to start storing characters
- len- 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 occurs
- IndexOutOfBoundsException- If an I/O error occurs
 
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skippublic long skip(long n) throws IOExceptionSkips characters.- Overrides:
- skipin class- Reader
- 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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readypublic boolean ready() throws IOExceptionTells whether this stream is ready to be read.- Overrides:
- readyin class- Reader
- 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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markSupportedpublic boolean markSupported() Tells whether this stream supports the mark() operation.- Overrides:
- markSupportedin class- Reader
- Returns:
- true if and only if this stream supports the mark operation.
 
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markpublic void mark(int readAheadLimit) throws IOExceptionMarks the present position in the stream.- Overrides:
- markin class- Reader
- 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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resetpublic void reset() throws IOExceptionResets the stream.- Overrides:
- resetin class- Reader
- Throws:
- IOException- If an I/O error occurs
 
 
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