* Note: Invoking close() on this class has no effect, and methods * of this class can be called after the stream has closed * without generating an IOException. * * @author Herb Jellinek * @since JDK1.1 */ public class CharArrayWriter extends Writer { /** * The buffer where data is stored. */ protected char buf[]; /** * The number of chars in the buffer. */ protected int count; /** * Creates a new CharArrayWriter. */ public CharArrayWriter() { this(32); } /** * Creates a new CharArrayWriter with the specified initial size. * * @param initialSize an int specifying the initial buffer size. * @exception IllegalArgumentException if initialSize is negative */ public CharArrayWriter(int initialSize) { if (initialSize < 0) { throw new IllegalArgumentException("Negative initial size: " + initialSize); } buf = new char[initialSize]; } /** * Writes a character to the buffer. */ public void write(int c) { synchronized (lock) { int newcount = count + 1; if (newcount > buf.length) { buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); } buf[count] = (char)c; count = newcount; } } /** * Writes characters to the buffer. * @param c the data to be written * @param off the start offset in the data * @param len the number of chars that are written */ public void write(char c[], int off, int len) { if ((off < 0) || (off > c.length) || (len < 0) || ((off + len) > c.length) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return; } synchronized (lock) { int newcount = count + len; if (newcount > buf.length) { buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); } System.arraycopy(c, off, buf, count, len); count = newcount; } } /** * Write a portion of a string to the buffer. * @param str String to be written from * @param off Offset from which to start reading characters * @param len Number of characters to be written */ public void write(String str, int off, int len) { synchronized (lock) { int newcount = count + len; if (newcount > buf.length) { buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); } str.getChars(off, off + len, buf, count); count = newcount; } } /** * Writes the contents of the buffer to another character stream. * * @param out the output stream to write to * @throws IOException If an I/O error occurs. */ public void writeTo(Writer out) throws IOException { synchronized (lock) { out.write(buf, 0, count); } } /** * Appends the specified character sequence to this writer. * *
An invocation of this method of the form out.append(csq) * behaves in exactly the same way as the invocation * *
* out.write(csq.toString())
*
* Depending on the specification of toString for the * character sequence csq, the entire sequence may not be * appended. For instance, invoking the toString method of a * character buffer will return a subsequence whose content depends upon * the buffer's position and limit. * * @param csq * The character sequence to append. If csq is * null, then the four characters "null" are * appended to this writer. * * @return This writer * * @since 1.5 */ public CharArrayWriter append(CharSequence csq) { String s = (csq == null ? "null" : csq.toString()); write(s, 0, s.length()); return this; } /** * Appends a subsequence of the specified character sequence to this writer. * *
An invocation of this method of the form out.append(csq, start, * end) when csq is not null, behaves in * exactly the same way as the invocation * *
* out.write(csq.subSequence(start, end).toString())
*
* @param csq
* The character sequence from which a subsequence will be
* appended. If csq is null, then characters
* will be appended as if csq contained the four
* characters "null".
*
* @param start
* The index of the first character in the subsequence
*
* @param end
* The index of the character following the last character in the
* subsequence
*
* @return This writer
*
* @throws IndexOutOfBoundsException
* If start or end are negative, start
* is greater than end, or end is greater than
* csq.length()
*
* @since 1.5
*/
public CharArrayWriter append(CharSequence csq, int start, int end) {
String s = (csq == null ? "null" : csq).subSequence(start, end).toString();
write(s, 0, s.length());
return this;
}
/**
* Appends the specified character to this writer.
*
* An invocation of this method of the form out.append(c) * behaves in exactly the same way as the invocation * *
* out.write(c)
*
* @param c
* The 16-bit character to append
*
* @return This writer
*
* @since 1.5
*/
public CharArrayWriter append(char c) {
write(c);
return this;
}
/**
* Resets the buffer so that you can use it again without
* throwing away the already allocated buffer.
*/
public void reset() {
count = 0;
}
/**
* Returns a copy of the input data.
*
* @return an array of chars copied from the input data.
*/
public char toCharArray()[] {
synchronized (lock) {
return Arrays.copyOf(buf, count);
}
}
/**
* Returns the current size of the buffer.
*
* @return an int representing the current size of the buffer.
*/
public int size() {
return count;
}
/**
* Converts input data to a string.
* @return the string.
*/
public String toString() {
synchronized (lock) {
return new String(buf, 0, count);
}
}
/**
* Flush the stream.
*/
public void flush() { }
/**
* Close the stream. This method does not release the buffer, since its
* contents might still be required. Note: Invoking this method in this class
* will have no effect.
*/
public void close() { }
}