Question

我需要以定时间隔从4个单独的.csv数据文件中提取数据，以同时输出数字。我只能按顺序提取文件。我不确定线程是否有用，而且我从来没能让它们正常运行。我的最终结果将在JFrame中显示输出。

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;


public class Inputtest {
    public static void main(String[] args) throws IOException,     InterruptedException {

        O21 a = new O21();
        O22 b = new O22();
        PH1 c = new PH1();
        PH2 d = new PH2();

        a.O21();
        b.O22();
        c.PH1();
        d.PH2();
    }
}

class O21
{
    public void O21() throws FileNotFoundException, InterruptedException {
        int e = 21;         //preset Level

        Scanner O1 = new Scanner(new File("O21.txt"));
        O1.useDelimiter(",");
        while (O1.hasNext()) {
            String a = O1.next();
            int aa = Integer.parseInt(a);
            Thread.sleep(500);      // Time delay for output

            if (a.trim().isEmpty()) {        continue;      }
            if(aa > (e + 1)) {
                System.out.println(a);
                System.out.println("Alarm high");
                continue;
            }
            if(aa < (e-1)) {
                System.out.println(a);
                System.out.println("Alarm Low");
                continue;
            }
            System.out.println(a);
        }
    }
}

class O22 {
    public void O22() throws FileNotFoundException, InterruptedException {
        double f = 20;          //preset Level
        Scanner O2 = new Scanner(new File("O22.txt"));
        O2.useDelimiter(",");
        while (O2.hasNext()) {
            String b = O2.next();
            int bb = Integer.parseInt(b);
            Thread.sleep(500);      // Time delay for output

            if (b.trim().isEmpty()) {        continue;      }

            if(bb > (f + 1)) {
                    System.out.println(b);
                    System.out.println("Alarm high");
                    continue;
            }

            if (bb < (f - 1)) {
                System.out.println(b);
                System.out.println("Alarm Low");
                continue;
            }

            System.out.println(b);
        }
    }
}

class PH1 {
    public void PH1() throws FileNotFoundException, InterruptedException {
        double g = 7;           //preset Level

        Scanner P1 = new Scanner(new File("PH1.txt"));
        P1.useDelimiter(",");
        while (P1.hasNext()) {
            String c = P1.next();
            double cc = Double.parseDouble(c);
            Thread.sleep(1000);     // Time delay for output

            if (c.trim().isEmpty()) {        continue;      }
            if (cc > (g + .5)) {
                System.out.println(c);
                System.out.println("Alarm high");
                continue;
            }

            if (cc < (g - .5)) {
                System.out.println(c);  
                System.out.println("Alarm Low");
                continue;
            }
            System.out.println(c);
        }
    }
}

class PH2 {
    public void PH2() throws FileNotFoundException, InterruptedException {
        double h = 7;           //preset Level

        Scanner P2 = new Scanner(new File("PH2.txt"));
        P2.useDelimiter(",");
        while (P2.hasNext()) {
            String d = P2.next();
            double dd = Double.parseDouble(d);
            Thread.sleep(1000);     // Time delay for output
            if (d.trim().isEmpty()) {        continue;      }
            if (dd > (h + .5)) {
                System.out.println(d);
                System.out.println("Alarm high");
                continue;
            }
            if (dd < (h - .5)) {
                System.out.println(d);
                System.out.println("Alarm Low");
                continue;
            }

            System.out.println(d);
        }
    }
}

Answer 1

是的，线程会帮助你。非常简单，

class O21 implements Runnable
{
    @Override public void run()  // Used to be your constructor
    {
        ....

并使用main方法：

...
Thread a = new Thread( new O21() );
a.start();
...

，同样适用于O22，PH1和PH2，它们现在都会同时执行。

您可以向Runnable添加构造函数，以便将refs传递给JFrame。我会把它留作练习。此外，SO和其他地方的线程编程有很多资源。

干杯，

同时读取.csv文件

1 个答案: