File	Doc	Category	Size	Date	Package
StringReader.java	API Doc	Java SE 6 API	5355	Tue Jun 10 00:25:34 BST 2008	java.io

StringReader

• java.lang.Object
  • java.io.Reader

Fields Summary
private String	str
private int	length
private int	next
private int	mark

Constructors Summary
public StringReader(String s) Creates a new string reader. param s String providing the character stream. this.str = s; this.length = s.length();

Methods Summary
public void	close() Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously closed stream has no effect. str = null;
private void	ensureOpen() Check to make sure that the stream has not been closed if (str == null) throw new IOException("Stream closed");
public void	mark(int readAheadLimit) Marks 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 string, there is no actual limit, so this argument must not be negative, but is otherwise ignored. exception IllegalArgumentException If readAheadLimit is < 0 exception IOException If an I/O error occurs if (readAheadLimit < 0){ throw new IllegalArgumentException("Read-ahead limit < 0"); } synchronized (lock) { ensureOpen(); mark = next; }
public boolean	markSupported() Tells whether this stream supports the mark() operation, which it does. return true;
public int	read() Reads a single character. return The character read, or -1 if the end of the stream has been reached exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); if (next >= length) return -1; return str.charAt(next++); }
public int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array. param cbuf Destination buffer param off Offset at which to start writing characters param len Maximum number of characters to read return The 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 > cbuf.length) || (len < 0) || ((off + len) > cbuf.length) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return 0; } if (next >= length) return -1; int n = Math.min(length - next, len); str.getChars(next, next + n, cbuf, off); next += n; return n; }
public boolean	ready() Tells whether this stream is ready to be read. return True if the next read() is guaranteed not to block for input exception IOException If the stream is closed synchronized (lock) { ensureOpen(); return true; }
public void	reset() Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); next = mark; }
public long	skip(long ns) Skips the specified number of characters in the stream. Returns the number of characters that were skipped. The ns parameter may be negative, even though the skip method of the {@link Reader} superclass throws an exception in this case. Negative values of ns cause the stream to skip backwards. Negative return values indicate a skip backwards. It is not possible to skip backwards past the beginning of the string. If the entire string has been read or skipped, then this method has no effect and always returns 0. exception IOException If an I/O error occurs synchronized (lock) { ensureOpen(); if (next >= length) return 0; // Bound skip by beginning and end of the source long n = Math.min(length - next, ns); n = Math.max(-next, n); next += n; return n; }