Extend DataInput & DataOutput to avoid copy of byte[]

"DataInput's void readFully(byte b[])" will cause an extra copy when reading bytes from DataInput. Sometimes business logic needs to read bytes from DataInput first, then process them conditionally(or will not process at all) , is it possible to support ByteBuffer api like:

public interface XDataInput extends DataInput

{     ByteBuffer readBuffer(int n); }

public interface XDataOutput extends DataOutput

{     void writeBuffer(ByteBuffer value); }

ByteArrayDataInputStream.java

@Override
public ByteBuffer readBuffer(int n)

{     ByteBuffer r = wrap(this.buf, this.pos, n); this.pos += n; return r; }

public interface Streamable

{     void writeTo(XDataOutput out) throws IOException;     void readFrom(XDataInput in) throws IOException, ClassNotFoundException; }