toByteArray() and
- * toString().
- *
- * Closing a ByteArrayOutputStream has no effect. The methods in
- * this class can be called after the stream has been closed without
- * generating an IOException.
- *
- * @author Arthur van Hoff
- * @since JDK1.0
- */
-
-public class ByteArrayOutputStream extends OutputStream {
-
- /**
- * The buffer where data is stored.
- */
- protected byte buf[];
-
- /**
- * The number of valid bytes in the buffer.
- */
- protected int count;
-
- /**
- * Creates a new byte array output stream. The buffer capacity is
- * initially 32 bytes, though its size increases if necessary.
- */
- public ByteArrayOutputStream() {
- this(32);
- }
-
- /**
- * Creates a new byte array output stream, with a buffer capacity of
- * the specified size, in bytes.
- *
- * @param size the initial size.
- * @exception IllegalArgumentException if size is negative.
- */
- public ByteArrayOutputStream(int size) {
- if (size < 0) {
- throw new IllegalArgumentException("Negative initial size: "
- + size);
- }
- buf = new byte[size];
- }
-
- /**
- * Increases the capacity if necessary to ensure that it can hold
- * at least the number of elements specified by the minimum
- * capacity argument.
- *
- * @param minCapacity the desired minimum capacity
- * @throws OutOfMemoryError if {@code minCapacity < 0}. This is
- * interpreted as a request for the unsatisfiably large capacity
- * {@code (long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE)}.
- */
- private void ensureCapacity(int minCapacity) {
- // overflow-conscious code
- if (minCapacity - buf.length > 0)
- grow(minCapacity);
- }
-
- /**
- * Increases the capacity to ensure that it can hold at least the
- * number of elements specified by the minimum capacity argument.
- *
- * @param minCapacity the desired minimum capacity
- */
- private void grow(int minCapacity) {
- // overflow-conscious code
- int oldCapacity = buf.length;
- int newCapacity = oldCapacity << 1;
- if (newCapacity - minCapacity < 0)
- newCapacity = minCapacity;
- if (newCapacity < 0) {
- if (minCapacity < 0) // overflow
- throw new OutOfMemoryError();
- newCapacity = Integer.MAX_VALUE;
- }
- buf = Arrays.copyOf(buf, newCapacity);
- }
-
- /**
- * Writes the specified byte to this byte array output stream.
- *
- * @param b the byte to be written.
- */
- public synchronized void write(int b) {
- ensureCapacity(count + 1);
- buf[count] = (byte) b;
- count += 1;
- }
-
- /**
- * Writes len bytes from the specified byte array
- * starting at offset off to this byte array output stream.
- *
- * @param b the data.
- * @param off the start offset in the data.
- * @param len the number of bytes to write.
- */
- public synchronized void write(byte b[], int off, int len) {
- if ((off < 0) || (off > b.length) || (len < 0) ||
- ((off + len) - b.length > 0)) {
- throw new IndexOutOfBoundsException();
- }
- ensureCapacity(count + len);
- System.arraycopy(b, off, buf, count, len);
- count += len;
- }
-
- /**
- * Writes the complete contents of this byte array output stream to
- * the specified output stream argument, as if by calling the output
- * stream's write method using out.write(buf, 0, count).
- *
- * @param out the output stream to which to write the data.
- * @exception IOException if an I/O error occurs.
- */
- public synchronized void writeTo(OutputStream out) throws IOException {
- out.write(buf, 0, count);
- }
-
- /**
- * Resets the count field of this byte array output
- * stream to zero, so that all currently accumulated output in the
- * output stream is discarded. The output stream can be used again,
- * reusing the already allocated buffer space.
- *
- * @see java.io.ByteArrayInputStream#count
- */
- public synchronized void reset() {
- count = 0;
- }
-
- /**
- * Creates a newly allocated byte array. Its size is the current
- * size of this output stream and the valid contents of the buffer
- * have been copied into it.
- *
- * @return the current contents of this output stream, as a byte array.
- * @see java.io.ByteArrayOutputStream#size()
- */
- public synchronized byte toByteArray()[] {
- return Arrays.copyOf(buf, count);
- }
-
- /**
- * Returns the current size of the buffer.
- *
- * @return the value of the count field, which is the number
- * of valid bytes in this output stream.
- * @see java.io.ByteArrayOutputStream#count
- */
- public synchronized int size() {
- return count;
- }
-
- /**
- * Converts the buffer's contents into a string decoding bytes using the
- * platform's default character set. The length of the new String
- * is a function of the character set, and hence may not be equal to the
- * size of the buffer.
- *
- *
This method always replaces malformed-input and unmappable-character - * sequences with the default replacement string for the platform's - * default character set. The {@linkplain java.nio.charset.CharsetDecoder} - * class should be used when more control over the decoding process is - * required. - * - * @return String decoded from the buffer's contents. - * @since JDK1.1 - */ - public synchronized String toString() { - return new String(buf, 0, count); - } - - /** - * Converts the buffer's contents into a string by decoding the bytes using - * the specified {@link java.nio.charset.Charset charsetName}. The length of - * the new String is a function of the charset, and hence may not be - * equal to the length of the byte array. - * - *
This method always replaces malformed-input and unmappable-character
- * sequences with this charset's default replacement string. The {@link
- * java.nio.charset.CharsetDecoder} class should be used when more control
- * over the decoding process is required.
- *
- * @param charsetName the name of a supported
- * {@linkplain java.nio.charset.Charset charset
- *
- */
- public void close() throws IOException {
- }
-
-}
}
- * @return String decoded from the buffer's contents.
- * @exception UnsupportedEncodingException
- * If the named charset is not supported
- * @since JDK1.1
- */
- public synchronized String toString(String charsetName)
- throws UnsupportedEncodingException
- {
- return new String(buf, 0, count, charsetName);
- }
-
- /**
- * Creates a newly allocated string. Its size is the current size of
- * the output stream and the valid contents of the buffer have been
- * copied into it. Each character c in the resulting string is
- * constructed from the corresponding element b in the byte
- * array such that:
- *
- *
- * @deprecated This method does not properly convert bytes into characters.
- * As of JDK 1.1, the preferred way to do this is via the
- *
- * c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
- *
toString(String enc) method, which takes an encoding-name
- * argument, or the toString() method, which uses the
- * platform's default character encoding.
- *
- * @param hibyte the high byte of each resulting Unicode character.
- * @return the current contents of the output stream, as a string.
- * @see java.io.ByteArrayOutputStream#size()
- * @see java.io.ByteArrayOutputStream#toString(String)
- * @see java.io.ByteArrayOutputStream#toString()
- */
- @Deprecated
- public synchronized String toString(int hibyte) {
- return new String(buf, hibyte, 0, count);
- }
-
- /**
- * Closing a ByteArrayOutputStream has no effect. The methods in
- * this class can be called after the stream has been closed without
- * generating an IOException.
- *