File	Doc	Category	Size	Date	Package
NullReader.java	API Doc	Android 1.5 API	10535	Wed May 06 22:42:46 BST 2009	org.apache.commons.io.input

NullReader

• java.lang.Object
  • java.io.Reader

public class TestReader extends NullReader {
public TestReader(int size) {
super(size);
}
protected char processChar() {
return ... // return required value here
}
protected void processChars(char[] chars, int offset, int length) {
for (int i = offset; i < length; i++) {
chars[i] = ... // set array value here
}
}
}

Fields Summary
private long	size
private long	position
private long	mark
private long	readlimit
private boolean	eof
private boolean	throwEofException
private boolean	markSupported

Constructors Summary
public NullReader(long size) Create a {@link Reader} that emulates a specified size which supports marking and does not throw EOFException. param size The size of the reader to emulate. this(size, true, false);
public NullReader(long size, boolean markSupported, boolean throwEofException) Create a {@link Reader} that emulates a specified size with option settings. param size The size of the reader to emulate. param markSupported Whether this instance will support the mark() functionality. param throwEofException Whether this implementation will throw an {@link EOFException} or return -1 when the end of file is reached. this.size = size; this.markSupported = markSupported; this.throwEofException = throwEofException;

Methods Summary
public void	close() Close this Reader - resets the internal state to the initial values. throws IOException If an error occurs. eof = false; position = 0; mark = -1;
private int	doEndOfFile() Handle End of File. return -1 if throwEofException is set to false throws EOFException if throwEofException is set to true. eof = true; if (throwEofException) { throw new EOFException(); } return -1;
public long	getPosition() Return the current position. return the current position. return position;
public long	getSize() Return the size this {@link Reader} emulates. return The size of the reader to emulate. return size;
public synchronized void	mark(int readlimit) Mark the current position. param readlimit The number of characters before this marked position is invalid. throws UnsupportedOperationException if mark is not supported. if (!markSupported) { throw new UnsupportedOperationException("Mark not supported"); } mark = position; this.readlimit = readlimit;
public boolean	markSupported() Indicates whether mark is supported. return Whether mark is supported or not. return markSupported;
protected int	processChar() Return a character value for the read() method. This implementation returns zero. return This implementation always returns zero. // do nothing - overridable by subclass return 0;
protected void	processChars(char[] chars, int offset, int length) Process the characters for the read(char[], offset, length) method. This implementation leaves the character array unchanged. param chars The character array param offset The offset to start at. param length The number of characters. // do nothing - overridable by subclass
public int	read(char[] chars, int offset, int length) Read the specified number characters into an array. param chars The character array to read into. param offset The offset to start reading characters into. param length The number of characters to read. return The number of characters read or -1 if the end of file has been reached and throwEofException is set to false. throws EOFException if the end of file is reached and throwEofException is set to true. throws IOException if trying to read past the end of file. if (eof) { throw new IOException("Read after end of file"); } if (position == size) { return doEndOfFile(); } position += length; int returnLength = length; if (position > size) { returnLength = length - (int)(position - size); position = size; } processChars(chars, offset, returnLength); return returnLength;
public int	read() Read a character. return Either The character value returned by processChar() or -1 if the end of file has been reached and throwEofException is set to false. throws EOFException if the end of file is reached and throwEofException is set to true. throws IOException if trying to read past the end of file. if (eof) { throw new IOException("Read after end of file"); } if (position == size) { return doEndOfFile(); } position++; return processChar();
public int	read(char[] chars) Read some characters into the specified array. param chars The character array to read into return The number of characters read or -1 if the end of file has been reached and throwEofException is set to false. throws EOFException if the end of file is reached and throwEofException is set to true. throws IOException if trying to read past the end of file. return read(chars, 0, chars.length);
public synchronized void	reset() Reset the stream to the point when mark was last called. throws UnsupportedOperationException if mark is not supported. throws IOException If no position has been marked or the read limit has been exceed since the last position was marked. if (!markSupported) { throw new UnsupportedOperationException("Mark not supported"); } if (mark < 0) { throw new IOException("No position has been marked"); } if (position > (mark + readlimit)) { throw new IOException("Marked position [" + mark + "] is no longer valid - passed the read limit [" + readlimit + "]"); } position = mark; eof = false;
public long	skip(long numberOfChars) Skip a specified number of characters. param numberOfChars The number of characters to skip. return The number of characters skipped or -1 if the end of file has been reached and throwEofException is set to false. throws EOFException if the end of file is reached and throwEofException is set to true. throws IOException if trying to read past the end of file. if (eof) { throw new IOException("Skip after end of file"); } if (position == size) { return doEndOfFile(); } position += numberOfChars; long returnLength = numberOfChars; if (position > size) { returnLength = numberOfChars - (position - size); position = size; } return returnLength;