java - 执行我的 java 程序后，从 pubnub 获取正确的发布数据，但后来不正确

Question

我创建了一个 java 文件，该文件在按下 IoT 调制解调器上的按钮后获取数据。IoT 设备通过 PubNub 发布协议(protocol)数据订阅此内容后，我正在从 PubNub 获取 java 程序中的数据。

接收到的数据是 ASCII 表示的十六进制值。

我将协议(protocol)数据作为单个字符串获取并转换为字符数组，然后从数组中获取数组的一部分并转换为十进制值。

执行程序后，我得到了正确的数据，但后来数据不正确。

这是我的完整代码:

import com.pubnub.api.Callback;
import com.pubnub.api.Pubnub;
import com.pubnub.api.PubnubException;

public class SubscribeTest {
    String PUB_KEY = "pub-c-a2a1d4ab...";
    String SUB_KEY = "sub-c-0ce5f84a...";
    String CHANNEL = "IOT1";
    Pubnub pn = new Pubnub(PUB_KEY,SUB_KEY);

    String receivedData = new String(); //to store the subscribed data
    char[] receivedDataInArray = new char[50];  //to store the converted string

    int deviceId = 0;
    int functionCode = 0;
    int productId =0;
    int timeHour = 0;
    int timeMin = 0;
    int dateDay = 0;
    int dateMonth = 0;
    int eventCount = 0;


    public void subTest() throws PubnubException {  
        try {

            System.out.println("Subscribed");
            pn.subscribe(CHANNEL, new Callback() {

                @Override
                public void successCallback(String arg0, Object arg1) {


                    System.out.println(arg1);
                    receivedData = (String)arg1;    //subscribed data stored 
                    System.out.println("DATA :-" + receivedData);
                    System.out.println("Message length :  "+receivedData.length());

                    for(int i=0; i<receivedData.length(); i++) {
                        receivedDataInArray[i] = receivedData.charAt(i);        //Received data converted into array
                    }

                    System.out.println(receivedDataInArray);

                    int tmp = 0;
                    for (int j = 0; j < 4 ; j++) {

                        if (j < 3) {
                            if(receivedDataInArray[j] > 0x39) {
                                if(receivedDataInArray[j] == 'A') {
                                    tmp = 0x0A;
                                }else if(receivedDataInArray[j] == 'B') {
                                    tmp = 0x0B;
                                }else if(receivedDataInArray[j] == 'C') {
                                    tmp = 0x0C;
                                }else if(receivedDataInArray[j] == 'D') {
                                    tmp = 0x0D;
                                }else if(receivedDataInArray[j] == 'E') {
                                    tmp = 0x0E;
                                }else if(receivedDataInArray[j] == 'F') {
                                    tmp = 0x0F;
                                }

                                deviceId |= tmp;
                                deviceId <<= 4;

                            } else {
                                tmp=receivedDataInArray[j]-0x30;
                                deviceId |= tmp;
                                deviceId <<= 4;
                            }
                        }else {
                            if (receivedDataInArray[j] > 0x39) {
                                if (receivedDataInArray[j] == 'A') {
                                    tmp = 0x0A;
                                }else if(receivedDataInArray[j] == 'B') {
                                    tmp = 0x0B;
                                }else if(receivedDataInArray[j] == 'C') {
                                    tmp = 0x0C;
                                }else if(receivedDataInArray[j] == 'D') {
                                    tmp = 0x0D;
                                }else if(receivedDataInArray[j] == 'E') {
                                    tmp = 0x0E;
                                }else if(receivedDataInArray[j] == 'F') {
                                    tmp = 0x0F;
                                }

                                deviceId |= tmp;
                            } else {
                                tmp = receivedDataInArray[j]-0x30;
                                deviceId |= tmp;
                            }
                        }   
                    }
                    System.out.println("device ID:--"+deviceId);

                    //for Product Id
                    tmp = receivedDataInArray[10]-0x30;
                    productId = tmp;
                    productId <<= 4;
                    tmp = receivedDataInArray[11]-0x30;
                    productId |= tmp;

                    //for Time Hour
                    tmp = receivedDataInArray[12]-0x30;
                    timeHour = tmp*10;
                    //timeHour <<= 4;
                    tmp = receivedDataInArray[13]-0x30;
                    timeHour += tmp;

                    //for Time Minute
                    tmp = receivedDataInArray[14]-0x30;
                    timeMin = tmp*10;
                    //timeMin <<= 4;
                    tmp = receivedDataInArray[15]-0x30;
                    timeMin += tmp;

                    //for Date Day
                    tmp = receivedDataInArray[16]-0x30;
                    dateDay = tmp*10;
                    //date <<= 4;
                    tmp = receivedDataInArray[17]-0x30;
                    dateDay += tmp;

                    //for month
                    tmp = receivedDataInArray[18]-0x30;
                    dateMonth = tmp*10;
                    //dateMonth <<= 4;
                    tmp = receivedDataInArray[19]-0x30;
                    dateMonth += tmp;

                    //for event count
                    for (int j = 20; j < 24 ; j++) {

                        if (j < 23) {
                            if(receivedDataInArray[j] > 0x39) {
                                if(receivedDataInArray[j] == 'A') {
                                    tmp=0x0A;
                                }else if(receivedDataInArray[j] == 'B') {
                                    tmp=0x0B;
                                }else if(receivedDataInArray[j] == 'C') {
                                    tmp=0x0C;
                                }else if(receivedDataInArray[j] == 'D') {
                                    tmp =0x0D;
                                }else if(receivedDataInArray[j] == 'E') {
                                    tmp=0x0E;
                                }else if(receivedDataInArray[j] == 'F') {
                                    tmp=0x0F;
                                }

                                eventCount |= tmp;
                                eventCount <<= 4;

                            } else {
                                tmp=receivedDataInArray[j]-0x30;
                                eventCount |= tmp;
                                eventCount <<= 4;
                            }
                        }else {
                            if (receivedDataInArray[j] > 0x39) {
                                if (receivedDataInArray[j] == 'A') {
                                    tmp = 0x0A;
                                }else if(receivedDataInArray[j] == 'B') {
                                    tmp = 0x0B;
                                }else if(receivedDataInArray[j] == 'C') {
                                    tmp = 0x0C;
                                }else if(receivedDataInArray[j] == 'D') {
                                    tmp = 0x0D;
                                }else if(receivedDataInArray[j] == 'E') {
                                    tmp = 0x0E;
                                }else if(receivedDataInArray[j] == 'F') {
                                    tmp = 0x0F;
                                }
                                eventCount |= tmp;
                            } else {
                                tmp = receivedDataInArray[j]-0x30;
                                eventCount |= tmp;
                            }
                        }   

                    }


                    System.out.println("***Received data from device***"+"\n\n"+
                            "Device id : "+deviceId+
                            "\nProduct Id: "+productId+
                            "\nTime Hour: "+timeHour+
                            "\nTime Minutes: "+timeMin+
                            "\nDate Day: "+dateDay+
                            "\nDate Month: "+dateMonth+
                            "\nEvent Count: "+eventCount);
                }

            });

        }catch (PubnubException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void main(String[] args) throws PubnubException {

        new SubscribeTest().subTest();
    }

}

如果我执行此操作，按下 IoT 调制解调器的按钮后，我将获得正确的数据，但如果我再次按下，则只有设备 ID 和事件计数有所不同。

这是我的输出:

执行后第一次

167303080003063001020001
DATA :-167303080003063001020001
Message length :  24
167303080003063001020001
device ID:--5747
***Received data from device***

Device id : 5747
Product Id: 3
Time Hour: 6
Time Minutes: 30
Date Day: 1
Date Month: 2
Event Count: 1

执行后第二次

167303080003063001020001
DATA :-167303080003063001020001
Message length :  24
167303080003063001020001
device ID:--23541363
***Received data from device***

Device id : 23541363
Product Id: 3
Time Hour: 6
Time Minutes: 30
Date Day: 1
Date Month: 2
Event Count: 4097

这里，167303080003063001020001是从设备获取的协议(protocol)数据对于两个输出都是相同的。

Callback()有什么问题吗？

Answer 1

设备 ID 和事件计数器的值采用先前值和当前值，并且在进程转换后，它被分配一个巨大的值。

因此，如果我在 successCallback() 中声明所有变量，那么每次调用此 block 后，所有变量的值将在整个过程执行后变为零，所有变量都将具有正确的值。

public void successCallback(String arg0, Object arg1) {

    int deviceId = 0;
    int functionCode = 0;
    int productId =0;
    int timeHour = 0;
    int timeMin = 0;
    int dateDay = 0;
    int dateMonth = 0;
    int eventCount = 0;

    System.out.println(arg1);
    receivedData = (String)arg1;    //subscribed data stored 
    System.out.println("DATA :-" + receivedData);
    System.out.println("Message length :  "+receivedData.length());

    for(int i=0; i<receivedData.length(); i++) {
        receivedDataInArray[i] = receivedData.charAt(i);        //Received data converted into array
    }
    .   .   .   .
    .   .   .   .
    .   .   .   .
}