e184. creating a stream on a bytebuffer.txt

来自「这里面包含了一百多个JAVA源文件」· 文本 代码 · 共 45 行

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;
            }
        };
    }