File	Doc	Category	Size	Date	Package
CharArrayReader.java	API Doc	Java SE 5 API	5932	Fri Aug 26 14:56:58 BST 2005	java.io

CharArrayReader

• java.lang.Object
  • java.io.Reader

Fields Summary
protected char[]	buf The character buffer.
protected int	pos The current buffer position.
protected int	markedPos The position of mark in buffer.
protected int	count The index of the end of this buffer. There is not valid data at or beyond this index.

Constructors Summary
public CharArrayReader(char[] buf) Create an CharArrayReader from the specified array of chars. param buf Input buffer (not copied) this.buf = buf; this.pos = 0; this.count = buf.length;
public CharArrayReader(char[] buf, int offset, int length) Create an CharArrayReader from the specified array of chars. The resulting reader will start reading at the given offset. The total number of char values that can be read from this reader will be either length or buf.length-offset, whichever is smaller. throws IllegalArgumentException If offset is negative or greater than buf.length, or if length is negative, or if the sum of these two values is negative. param buf Input buffer (not copied) param offset Offset of the first char to read param length Number of chars to read if ((offset < 0) || (offset > buf.length) || (length < 0) || ((offset + length) < 0)) { throw new IllegalArgumentException(); } this.buf = buf; this.pos = offset; this.count = Math.min(offset + length, buf.length); this.markedPos = offset;

Methods Summary
public void	close() Close the stream. buf = null;
private void	ensureOpen() Check to make sure that the stream has not been closed if (buf == null) throw new IOException("Stream closed");
public void	mark(int readAheadLimit) Mark the present position in the stream. Subsequent calls to reset() will reposition the stream to this point. param readAheadLimit Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a character array, there is no actual limit; hence this argument is ignored. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); markedPos = pos; }
public boolean	markSupported() Tell whether this stream supports the mark() operation, which it does. return true;
public int	read() Read a single character. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); if (pos >= count) return -1; else return buf[pos++]; }
public int	read(char[] b, int off, int len) Read characters into a portion of an array. param b Destination buffer param off Offset at which to start storing characters param len Maximum number of characters to read return The actual number of characters read, or -1 if the end of the stream has been reached exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); if ((off < 0) || (off > b.length) || (len < 0) || ((off + len) > b.length) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return 0; } if (pos >= count) { return -1; } if (pos + len > count) { len = count - pos; } if (len <= 0) { return 0; } System.arraycopy(buf, pos, b, off, len); pos += len; return len; }
public boolean	ready() Tell whether this stream is ready to be read. Character-array readers are always ready to be read. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); return (count - pos) > 0; }
public void	reset() Reset the stream to the most recent mark, or to the beginning if it has never been marked. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); pos = markedPos; }
public long	skip(long n) Skip characters. Returns the number of characters that were skipped. The n parameter may be negative, even though the skip method of the {@link Reader} superclass throws an exception in this case. If n is negative, then this method does nothing and returns 0. param n The number of characters to skip return The number of characters actually skipped exception IOException If the stream is closed, or an I/O error occurs synchronized (lock) { ensureOpen(); if (pos + n > count) { n = count - pos; } if (n < 0) { return 0; } pos += n; return n; }