Subclasses that intend to support efficient single-character output * should override this method. * * @param c * int specifying a character to be written * * @throws IOException * If an I/O error occurs */ public void write(int c) throws IOException { synchronized (lock) { if (writeBuffer == null){ writeBuffer = new char[writeBufferSize]; } writeBuffer[0] = (char) c; write(writeBuffer, 0, 1); } } /** * Writes an array of characters. * * @param cbuf * Array of characters to be written * * @throws IOException * If an I/O error occurs */ public void write(char cbuf[]) throws IOException { write(cbuf, 0, cbuf.length); } /** * Writes a portion of an array of characters. * * @param cbuf * Array of characters * * @param off * Offset from which to start writing characters * * @param len * Number of characters to write * * @throws IOException * If an I/O error occurs */ abstract public void write(char cbuf[], int off, int len) throws IOException; /** * Writes a string. * * @param str * String to be written * * @throws IOException * If an I/O error occurs */ public void write(String str) throws IOException { write(str, 0, str.length()); } /** * Writes a portion of a string. * * @param str * A String * * @param off * Offset from which to start writing characters * * @param len * Number of characters to write * * @throws IndexOutOfBoundsException * If off is negative, or len is negative, * or off+len is negative or greater than the length * of the given string * * @throws IOException * If an I/O error occurs */ public void write(String str, int off, int len) throws IOException { synchronized (lock) { char cbuf[]; if (len <= writeBufferSize) { if (writeBuffer == null) { writeBuffer = new char[writeBufferSize]; } cbuf = writeBuffer; } else { // Don't permanently allocate very large buffers. cbuf = new char[len]; } str.getChars(off, (off + len), cbuf, 0); write(cbuf, 0, len); } } /** * 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 * * @throws IOException * If an I/O error occurs * * @since 1.5 */ public Writer append(CharSequence csq) throws IOException { if (csq == null) write("null"); else write(csq.toString()); return this; } /** * Appends a subsequence of the specified character sequence to this writer. * Appendable. * *
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()
*
* @throws IOException
* If an I/O error occurs
*
* @since 1.5
*/
public Writer append(CharSequence csq, int start, int end) throws IOException {
CharSequence cs = (csq == null ? "null" : csq);
write(cs.subSequence(start, end).toString());
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
*
* @throws IOException
* If an I/O error occurs
*
* @since 1.5
*/
public Writer append(char c) throws IOException {
write(c);
return this;
}
/**
* Flushes the stream. If the stream has saved any characters from the
* various write() methods in a buffer, write them immediately to their
* intended destination. Then, if that destination is another character or
* byte stream, flush it. Thus one flush() invocation will flush all the
* buffers in a chain of Writers and OutputStreams.
*
* If the intended destination of this stream is an abstraction provided * by the underlying operating system, for example a file, then flushing the * stream guarantees only that bytes previously written to the stream are * passed to the operating system for writing; it does not guarantee that * they are actually written to a physical device such as a disk drive. * * @throws IOException * If an I/O error occurs */ abstract public void flush() throws IOException; /** * Closes the stream, flushing it first. Once the stream has been closed, * further write() or flush() invocations will cause an IOException to be * thrown. Closing a previously closed stream has no effect. * * @throws IOException * If an I/O error occurs */ abstract public void close() throws IOException; }