Add ByteBufferBackedInputStream

src/main/java/org/warp/commonutils/stream/ByteBufferBackedInputStream.java

@@ -0,0 +1,28 @@
+package org.warp.commonutils.stream;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * Simple {@link InputStream} implementation that exposes currently
+ * available content of a {@link ByteBuffer}.
+ */
+public class ByteBufferBackedInputStream extends InputStream {
+	protected final ByteBuffer _b;
+
+	public ByteBufferBackedInputStream(ByteBuffer buf) { _b = buf; }
+
+	@Override public int available() { return _b.remaining(); }
+
+	@Override
+	public int read() throws IOException { return _b.hasRemaining() ? (_b.get() & 0xFF) : -1; }
+
+	@Override
+	public int read(byte[] bytes, int off, int len) throws IOException {
+		if (!_b.hasRemaining()) return -1;
+		len = Math.min(len, _b.remaining());
+		_b.get(bytes, off, len);
+		return len;
+	}
+}