The Java Developers Almanac 1.4


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Home > List of Packages > java.nio  [27 examples] > Streams  [2 examples]

e184. Creating a Stream on a ByteBuffer

This example implements methods for creating an input or output stream on a ByteBuffer.
    // Obtain a ByteBuffer; see e158 Creating a ByteBuffer.
    ByteBuffer buf = ByteBuffer.allocate(10);
    
    // Create an output stream on the ByteBuffer
    OutputStream os = newOutputStream(buf);
    
    // Create an input stream on the ByteBuffer
    InputStream is = newInputStream(buf);
    
    // Returns an output stream for a ByteBuffer.
    // The write() methods use the relative ByteBuffer put() methods.
    public static OutputStream newOutputStream(final ByteBuffer buf) {
        return new OutputStream() {
            public synchronized void write(int b) throws IOException {
                buf.put((byte)b);
            }
    
            public synchronized void write(byte[] bytes, int off, int len) throws IOException {
                buf.put(bytes, off, len);
            }
        };
    }
    
    // Returns an input stream for a ByteBuffer.
    // The read() methods use the relative ByteBuffer get() methods.
    public static InputStream newInputStream(final ByteBuffer buf) {
        return new InputStream() {
            public synchronized int read() throws IOException {
                if (!buf.hasRemaining()) {
                    return -1;
                }
                return buf.get();
            }
    
            public synchronized int read(byte[] bytes, int off, int len) throws IOException {
                // Read only what's left
                len = Math.min(len, buf.remaining());
                buf.get(bytes, off, len);
                return len;
            }
        };
    }

 Related Examples
e183. Creating a Stream from a Channel

See also: Byte Buffers    File Locking    Files    Sockets   


© 2002 Addison-Wesley.