从字节缓冲区构建xml消息

Question

我有一个传递了一个字节数组的函数。这些字节可以包含xml消息的一部分，整体或整体和一部分。我已成功使用状态机来尝试解析消息，直到今天我们意识到如果第二个来源向我们发送数据，我可以获得消息的前半部分并且在第二个来源的另一个消息开始之后立即。我希望能够通过丢弃无序的消息来纠正这个问题。我不认为我应该存储它并保持它直到完成。

这是我的状态机：

for (int i = 0; i < bytes.length; i++)
    {
        byte data = bytes[i];

        //based on the read state, perform an action.  This is attempting to 
        //determine if we are reading the beginning of a message, or the end of the message.
        if (bufferIndex == BmsConstants.MAX_DRAWING_LENGTH)
        {
            resetState();               
        }

        switch (readState)
        {
            case SYNC:
                //we've read:  <
                if (data == '<')
                {
                    readState = DrawingDeviceParserState.START_LT;
                    buff[bufferIndex++] = (char) data;
                } else
                {
                    resetState();
                }
                break;
            case START_LT:
                //we've read:  <?
                if (data == '?')
                {
                    readState = DrawingDeviceParserState.START_QM;
                    buff[bufferIndex++] = (char) data;
                } else
                {
                    resetState();
                }
                break;
            case START_QM:
                //we've read:  <?x
                if (data == 'x')
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                } else
                {
                    resetState();
                }
                break;
            case START_X:
                //we've read:  <, now just read until we get to the </event>
                if (data == '<')
                {
                    readState = DrawingDeviceParserState.END_LT;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_LT:
                //we've read:  </
                if (data == '/')
                {
                    readState = DrawingDeviceParserState.END_SLASH;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_SLASH:
                //we've read:  </e
                if (data == 'e')
                {
                    readState = DrawingDeviceParserState.END_E;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_E:
                //we've read:  </ev
                if (data == 'v')
                {
                    readState = DrawingDeviceParserState.END_V;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_V:
                //we've read:  </eve
                if (data == 'e')
                {
                    readState = DrawingDeviceParserState.END_E1;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_E1:
                //we've read:  </even
                if (data == 'n')
                {
                    readState = DrawingDeviceParserState.END_N;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_N:
                //we've read:  </event
                if (data == 't')
                {
                    readState = DrawingDeviceParserState.END_T;
                    buff[bufferIndex++] = (char) data;
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
            case END_T:
                //we've read:  </event>  
                //End of the message, now we can parse it.
                if (data == '>')
                {
                    //readState = DrawingDeviceParserState.END_GT;
                    buff[bufferIndex++] = (char) data;

                    parseXml(new String(buff, 0, bufferIndex));
                    resetState();
                }
                else
                {
                    readState = DrawingDeviceParserState.START_X;
                    buff[bufferIndex++] = (char) data;
                }
                break;
        }
    }

缺点是这个状态机位于START_X的情况下。我将继续阅读，直到我找到标签，在2个消息填充在一起的情况下，将在第二个消息的末尾。 我希望有人能做的就是建议我状态机不是我应该做的，或修改我的代码/逻辑以更好地处理这种边缘情况。