+ * The class FilterOutputStream itself simply overrides
+ * all methods of OutputStream with versions that pass
+ * all requests to the underlying output stream. Subclasses of
+ * FilterOutputStream may further override some of these
+ * methods as well as provide additional methods and fields.
+ *
+ * @author Jonathan Payne
+ * @since JDK1.0
+ */
+public
+class FilterOutputStream extends OutputStream {
+ /**
+ * The underlying output stream to be filtered.
+ */
+ protected OutputStream out;
+
+ /**
+ * Creates an output stream filter built on top of the specified
+ * underlying output stream.
+ *
+ * @param out the underlying output stream to be assigned to
+ * the field this.out for later use, or
+ * null if this instance is to be
+ * created without an underlying stream.
+ */
+ public FilterOutputStream(OutputStream out) {
+ this.out = out;
+ }
+
+ /**
+ * Writes the specified byte to this output stream.
+ *
+ * The write method of FilterOutputStream
+ * calls the write method of its underlying output stream,
+ * that is, it performs out.write(b).
+ *
+ * Implements the abstract write method of OutputStream.
+ *
+ * @param b the byte.
+ * @exception IOException if an I/O error occurs.
+ */
+ public void write(int b) throws IOException {
+ out.write(b);
+ }
+
+ /**
+ * Writes b.length bytes to this output stream.
+ *
+ * The write method of FilterOutputStream
+ * calls its write method of three arguments with the
+ * arguments b, 0, and
+ * b.length.
+ *
+ * Note that this method does not call the one-argument
+ * write method of its underlying stream with the single
+ * argument b.
+ *
+ * @param b the data to be written.
+ * @exception IOException if an I/O error occurs.
+ * @see java.io.FilterOutputStream#write(byte[], int, int)
+ */
+ public void write(byte b[]) throws IOException {
+ write(b, 0, b.length);
+ }
+
+ /**
+ * Writes len bytes from the specified
+ * byte array starting at offset off to
+ * this output stream.
+ *
+ * The write method of FilterOutputStream
+ * calls the write method of one argument on each
+ * byte to output.
+ *
+ * Note that this method does not call the write method
+ * of its underlying input stream with the same arguments. Subclasses
+ * of FilterOutputStream should provide a more efficient
+ * implementation of this method.
+ *
+ * @param b the data.
+ * @param off the start offset in the data.
+ * @param len the number of bytes to write.
+ * @exception IOException if an I/O error occurs.
+ * @see java.io.FilterOutputStream#write(int)
+ */
+ public void write(byte b[], int off, int len) throws IOException {
+ if ((off | len | (b.length - (len + off)) | (off + len)) < 0)
+ throw new IndexOutOfBoundsException();
+
+ for (int i = 0 ; i < len ; i++) {
+ write(b[off + i]);
+ }
+ }
+
+ /**
+ * Flushes this output stream and forces any buffered output bytes
+ * to be written out to the stream.
+ *
+ * The flush method of FilterOutputStream
+ * calls the flush method of its underlying output stream.
+ *
+ * @exception IOException if an I/O error occurs.
+ * @see java.io.FilterOutputStream#out
+ */
+ public void flush() throws IOException {
+ out.flush();
+ }
+
+ /**
+ * Closes this output stream and releases any system resources
+ * associated with the stream.
+ *
+ * The close method of FilterOutputStream
+ * calls its flush method, and then calls the
+ * close method of its underlying output stream.
+ *
+ * @exception IOException if an I/O error occurs.
+ * @see java.io.FilterOutputStream#flush()
+ * @see java.io.FilterOutputStream#out
+ */
+ public void close() throws IOException {
+ try {
+ flush();
+ } catch (IOException ignored) {
+ }
+ out.close();
+ }
+}