com.helger.commons.io.stream

Class NonBlockingBufferedReader

java.lang.Object

java.io.Reader

com.helger.commons.io.stream.NonBlockingBufferedReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class NonBlockingBufferedReader
extends Reader

A non-synchronized copy of the class BufferedReader.

Author:

Philip Helger

See Also:

BufferedReader

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
NonBlockingBufferedReader(Reader aReader) Creates a buffering character-input stream that uses a default-sized input buffer.
NonBlockingBufferedReader(Reader aReader, int nSize) Creates a buffering character-input stream that uses an input buffer of the specified size.

Method Summary

Modifier and Type	Method and Description
void	close()
void	mark(int nReadAheadLimit) Marks the present position in the stream.
boolean	markSupported() Tells whether this stream supports the mark() operation, which it does.
int	read() Reads a single character.
int	read(char[] cbuf, int nOfs, int nLen) Reads characters into a portion of an array.
String	readLine() Reads a line of text.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream to the most recent mark.
long	skip(long nBytes) Skips characters.

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NonBlockingBufferedReader

public NonBlockingBufferedReader(@Nonnull
                                 Reader aReader)

Creates a buffering character-input stream that uses a default-sized input buffer.

Parameters:

aReader - A Reader

NonBlockingBufferedReader

public NonBlockingBufferedReader(@Nonnull
                                 Reader aReader,
                                 @Nonnegative
                                 int nSize)

Creates a buffering character-input stream that uses an input buffer of the specified size.

Parameters:

aReader - A Reader

nSize - Input-buffer size

Throws:

IllegalArgumentException - If size is ≤ 0

Method Detail

read

public int read()
         throws IOException

Reads a single character.

Overrides:

read in 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

read

public int read(char[] cbuf,
                int nOfs,
                int nLen)
         throws IOException

Reads characters into a portion of an array.

This method implements the general contract of the corresponding read method of the Reader class. As an additional convenience, it attempts to read as many characters as possible by repeatedly invoking the read method of the underlying stream. This iterated read continues until one of the following conditions becomes true:

• The specified number of characters have been read,
• The read method of the underlying stream returns -1, indicating end-of-file, or
• The ready method of the underlying stream returns false, indicating that further input requests would block.

If the first read on the underlying stream returns -1 to indicate end-of-file then this method returns -1. Otherwise this method returns the number of characters actually read.

Subclasses of this class are encouraged, but not required, to attempt to read as many characters as possible in the same fashion.

Ordinarily this method takes characters from this stream's character buffer, filling it from the underlying stream as necessary. If, however, the buffer is empty, the mark is not valid, and the requested length is at least as large as the buffer, then this method will read characters directly from the underlying stream into the given array. Thus redundant NonBlockingBufferedReaders will not copy data unnecessarily.

Specified by:

read in class Reader

Parameters:

cbuf - Destination buffer

nOfs - Offset at which to start storing characters

nLen - 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

readLine

@Nullable
public String readLine()
                           throws IOException

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

Returns:

A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

skip

public long skip(long nBytes)
          throws IOException

Skips characters.

Overrides:

skip in class Reader

Parameters:

nBytes - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

IllegalArgumentException - If n is negative.

IOException - If an I/O error occurs

ready

public boolean ready()
              throws IOException

Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.

Overrides:

ready in class Reader

Returns:

true if the reader is ready

Throws:

IOException - If an I/O error occurs

markSupported

public boolean markSupported()

Tells whether this stream supports the mark() operation, which it does.

Overrides:

markSupported in class Reader

Returns:

Always true

mark

public void mark(@Nonnegative
                 int nReadAheadLimit)
          throws IOException

Marks the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point.

Overrides:

mark in class Reader

Parameters:

nReadAheadLimit - Limit on the number of characters that may be read while still preserving the mark. An attempt to reset the stream after reading characters up to this limit or beyond may fail. A limit value larger than the size of the input buffer will cause a new buffer to be allocated whose size is no smaller than limit. Therefore large values should be used with care.

Throws:

IllegalArgumentException - If readAheadLimit is %lt; 0

IOException - If an I/O error occurs

reset

public void reset()
           throws IOException

Resets the stream to the most recent mark.

Overrides:

reset in class Reader

Throws:

IOException - If the stream has never been marked, or if the mark has been invalidated

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader

Throws:

IOException