java - 提高我的计时器线程的准确性

Question

下面我有一个每秒更新一次“时钟”标签的线程。一旦线程达到 600(10 分钟)，计时器就会停止。线程似乎每分钟拖尾大约五秒钟。所以当 val = 60 时，实际上可能已经过去了 65 秒。我正在使用 midp，所以我认为我无法引入任何 api 来帮助我完成这项任务。我怎样才能提高类(class)以下的准确性？我认为让它变慢的是方法 convertValToTimerString，是否有更好的方法将当前计时器 val 转换为分钟:秒格式而不使用 java 格式化程序 api？

谢谢，

public class LabelTimerUpdaterThread implements Runnable{

    public static int val = 0;
    private int minuteValueInt = 0;
    private int secondValueInt = 0;
    private int tempSecondValueInt;
    public boolean isRunning = true;

    public LabelTimerUpdaterThread(){

    }

    public void run() {
        while(isRunning){
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            val += 1;


            incrementTimer();

            if(val == 600){
                break;
            }
        }
    }

    private void incrementTimer(){
        Screen.timerLabel.setText(convertValToTimerString(val));
    }

    private String convertValToTimerString(int val){

        String minuteValString = "";
        String secondValString = "";

        if(val < 10){
            minuteValString = "00";
            secondValString = "0"+String.valueOf(val);
            return minuteValString+":"+secondValString;
        }

        if(val < 60){
            minuteValString = "00";
            secondValString = String.valueOf(val);
            return minuteValString+":"+secondValString;
        }

        if(val % 60 == 0){
            ++minuteValueInt;
        }

            if(minuteValueInt < 10){
                minuteValString = "0"+String.valueOf(minuteValueInt);
                int secondVal = val % 60;
                if(secondVal < 10){
                    return minuteValString+":0"+String.valueOf(secondVal);
                }
                else {
                    return minuteValString+":"+String.valueOf(secondVal);
                }
            }

        return "10:00";
    }

    public void stopThread(){
        this.isRunning = false;
    }

好的，现在我在尝试更新计时器标签时收到 IllegalStateException - 这是我的代码-

我在这里实例化我的标签 -

timerLabel = new CustomLabelField("00:00" , Field.FIELD_LEFT , Constants.SMALL_FONT , Color.BLACK, Bitmap.getBitmapResource("bg_clock_white.png"));

UpdateValTimer timer = new UpdateValTimer(th);
timer.startTimer();

此类创建计时器类并创建将更新计时器标签的类。

public class UpdateValTimer {

    private Timer timer;
    private int val = 0;
    private UpdateView uv;
    private final CustomLabelField customLabelField;

    public UpdateValTimer(CustomLabelField field) {
        this.customLabelField = field;
    }

    public void startTimer(){
        timer = new Timer();
        uv = new UpdateView(customLabelField);
        Thread t = new Thread(uv);
        t.start();

        timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {
                ++val;      
            }
        }, 1000, 1000);
    }
}

这个类更新定时器标签 - 公共(public)类 UpdateView 实现 Runnable{

    private int val = 0;
    private int minuteValueInt = 0;
    private final CustomLabelField timerLabel;

    public UpdateView(CustomLabelField timerLabel) {
        this.timerLabel = timerLabel;
    }

    public void run() {
        while(true){
            this.timerLabel.setText(convertValToTimerString(this.val));
        }
    }

     private String convertValToTimerString(int val){

            String minuteValString = "";
            String secondValString = "";

            if(val < 10){
                minuteValString = "00";
                secondValString = "0"+String.valueOf(val);
                return minuteValString+":"+secondValString;
            }

            if(val < 60){
                minuteValString = "00";
                secondValString = String.valueOf(val);
                return minuteValString+":"+secondValString;
            }

            if(val % 60 == 0){
                ++minuteValueInt;
            }

                if(minuteValueInt < 10){
                    minuteValString = "0"+String.valueOf(minuteValueInt);
                    int secondVal = val % 60;
                    if(secondVal < 10){
                        return minuteValString+":0"+String.valueOf(secondVal);
                    }
                    else {
                        return minuteValString+":"+String.valueOf(secondVal);
                    }
                }

            return "10:00";
        }

}

感谢您的帮助

经过一些初步测试后，此代码似乎可以正常工作。

感谢大家的帮助。

欢迎对我可以做得更好的任何意见。

public class UpdateValTimer{

    private int minuteValueInt = 0;
    private Timer timer;
    private int val = 0;
    private UpdateView uv;
    private CustomLabelField customLabelField;

    public UpdateValTimer(CustomLabelField field) {
        this.customLabelField = field;
    }

    public void startTimer(){
        timer = new Timer();
            uv = new UpdateView(customLabelField);
            Thread t = new Thread(uv);
            t.start();

        timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {             
                ++val;      
                uv.setVal(convertValToTimerString(val));
            }
        }, 1000, 1000);


    }

     private String convertValToTimerString(int val){

            String minuteValString = "";
            String secondValString = "";

            if(val < 10){
                minuteValString = "00";
                secondValString = "0"+String.valueOf(val);
                return minuteValString+":"+secondValString;
            }

            if(val < 60){
                minuteValString = "00";
                secondValString = String.valueOf(val);
                return minuteValString+":"+secondValString;
            }

            if(val % 60 == 0){
                ++minuteValueInt;
            }

                if(minuteValueInt < 10){
                    minuteValString = "0"+String.valueOf(minuteValueInt);
                    int secondVal = val % 60;
                    if(secondVal < 10){
                        return minuteValString+":0"+String.valueOf(secondVal);
                    }
                    else {
                        return minuteValString+":"+String.valueOf(secondVal);
                    }
                }

            return "10:00";
        }
}


public class UpdateView implements Runnable{

    private String timeElapsedCounter;
    private final CustomLabelField timerLabel;

    public UpdateView(CustomLabelField timerLabel) {
        this.timerLabel = timerLabel;
    }

    public void setVal(String timeElapsedCounter){
        this.timeElapsedCounter = timeElapsedCounter;
    }

    public void run() {

        while(true){
        synchronized(Application.getEventLock()){
            timerLabel.setText(this.timeElapsedCounter);
        }
        }
    }

}


        timerLabel = new CustomLabelField("00:00" , Field.FIELD_LEFT , Constants.SMALL_FONT , Color.BLACK, Bitmap.getBitmapResource("bg_clock_white.png"));

        UpdateValTimer timer = new UpdateValTimer(timerLabel);
        timer.startTimer();

Answer 1

Thread.sleep(1000);

将线程置于 hibernate 状态 至少 1 秒，然后返回到准备运行状态，这不保证它会立即运行，它只是“准备就绪”安排在未来的任何时间运行”。何时运行它取决于线程调度程序。例如，您可能想要检查系统时间以真正了解经过了多少时间......