public StringReader(String s) 
{
        this.str = s;
        this.length = s.length();
}

Creates a new string reader.

Parameters:

s - String providing the character stream.

 public  void close() 
{
        str = null;
}

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.

 public  void mark(int readAheadLimit) throws IOException 
{
        if (readAheadLimit <  0){
            throw new IllegalArgumentException("Read-ahead limit <  0");
        }
        synchronized (lock) {
            ensureOpen();
            mark = next;
        }
}

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

 public boolean markSupported() 
{
        return true;
}

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

 public int read() throws IOException 
{
        synchronized (lock) {
            ensureOpen();
            if (next  >= length)
                return -1;
            return str.charAt(next++);
        }
}

Reads a single character.

 public int read(char[] cbuf,
    int off,
    int len) throws IOException 
{
        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;
        }
}

Reads characters into a portion of an array.

 public boolean ready() throws IOException 
{
        synchronized (lock) {
        ensureOpen();
        return true;
        }
}

Tells whether this stream is ready to be read.

 public  void reset() throws IOException 
{
        synchronized (lock) {
            ensureOpen();
            next = mark;
        }
}

Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.

 public long skip(long ns) throws IOException 
{
        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;
        }
}

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 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.