@Override
public IMessage recognize(ByteBuffer buf) throws MessageParseException {
// 长度尚不足，确保可读长度超过4字节
if (buf.remaining() < IMessage.MIN_MESSAGE_LENGTH) {
return null;
}
// 读取前4字节
int len = buf.getShort(); // 预期长度
short type = buf.getShort();
if (type == MessageType.FLASH_POLICY) {
// Policy请求
boolean finished = false;
// 找到结束的'\0'标志
while (buf.remaining() > 0) {
byte b = buf.get();
if (b == 0) {
finished = true;
break;
}
}
if (finished) {
// Policy请求全部接收完毕
} else {
// 不足，下次继续
return null;
}
} else {
// 普通消息，检查长度是否满足
if (buf.remaining() < len - IMessage.HEADER_SIZE) {
return null;
}
}
return createMessage(type);
}
public static short readShort(ByteBuffer buffer) {
if (buffer != null) {
return buffer.getShort();
} else {
return 0;
}
}
protected static String readString(String charset, ByteBuffer buffer) {
short len = buffer.getShort();
byte[] bytes = new byte[len];
buffer.get(bytes);
try {
return new String(bytes, charset);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return "";
}
}
/**
* 从ByteBuffer解析得到PropertyBag
*
* @param buf 采用mina的ByteBuffer，因为这个支持自动增长
* @return
*/
public static PropertyBag readBuffer(ByteBuffer buf) {
PropertyBag bag = new PropertyBag();
short fieldCount = buf.getShort();
for (int i = 0; i < fieldCount; i++) {
int property = buf.getInt();
ValueType type = getTypeCode(buf.get());
Object val = ProtocolUtils.readValueFromPkt(buf, type);
bag.put(property, val);
}
return bag;
}