/**
* Convert the given bytes into a <code>JdwpPacket</code>. Uses the abstract method <code>
* myFromBytes</code> to allow subclasses to process data.
*
* <p>If the given data does not represent a valid JDWP packet, it returns <code>null</code>.
*
* @param bytes packet data from the wire
* @return number of bytes in <code>bytes</code> processed
*/
public static JdwpPacket fromBytes(byte[] bytes) {
int i = 0;
int length =
((bytes[i++] & 0xff) << 24
| (bytes[i++] & 0xff) << 16
| (bytes[i++] & 0xff) << 8
| (bytes[i++] & 0xff));
int id = 0;
byte flags = 0;
if (bytes.length == length) {
id =
((bytes[i++] & 0xff) << 24
| (bytes[i++] & 0xff) << 16
| (bytes[i++] & 0xff) << 8
| (bytes[i++] & 0xff));
flags = bytes[i++];
Class clazz = null;
if (flags == 0) clazz = JdwpCommandPacket.class;
else if ((flags & JDWP_FLAG_REPLY) != 0) clazz = JdwpReplyPacket.class;
else {
// Malformed packet. Discard it.
return null;
}
JdwpPacket pkt = null;
try {
pkt = (JdwpPacket) clazz.newInstance();
} catch (InstantiationException ie) {
// Discard packet
return null;
} catch (IllegalAccessException iae) {
// Discard packet
return null;
}
pkt.setId(id);
pkt.setFlags(flags);
i += pkt.myFromBytes(bytes, i);
byte[] data = new byte[length - i];
System.arraycopy(bytes, i, data, 0, data.length);
pkt.setData(data);
return pkt;
}
return null;
}
