java - 如何在 IO 操作期间显示进度

Question

我想从数组中读取元素并将读取进度显示为并行进程读取。

我有两个内部类:

public class NumbersCounter {

    int totalCountOfLines;
    int currentCountOfLines = 1;

    public NumbersCounter() throws FileNotFoundException, IOException {    
        new Read();
        new Progress();
    }

    public static void main(String[] args) {
        try {
            new NumbersCounter();
        } catch (FileNotFoundException ex) {
            Logger.getLogger(NumbersCounter.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(NumbersCounter.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    class Progress extends Thread {  
        public Progress() {
            start();
        }

        @Override
        public void run() {        
            synchronized(new Object()) {
                while (currentCountOfLines <= totalCountOfLines) {
                    System.out.println(currentCountOfLines / totalCountOfLines * 100 + "%");
                    Thread.yield();
                }            
            }
    }}

    class Read extends Thread {
        private FileHandler fh = new FileHandler("ololo.txt");
        private String[] lines;

        public Read() throws FileNotFoundException, IOException {
            this.lines = fh.readFromFile();
            start();
        }

        @Override
        public void run() {

            totalCountOfLines = this.lines.length;

            if (totalCountOfLines > 0) {
                synchronized(new Object()) {
                    for (String line : lines) {
                        currentCountOfLines++;   
                        Thread.yield();
                    }

                }
            } else {
                totalCountOfLines = 0;
            }    
        }
    }
}

当执行Read Thread的第一步时，我需要执行Progress线程，然后执行Read，然后执行Progress。

Answer 1

使用javax.swing.ProgressMonitorInputStream类作为输入流的包装器，它显示进度对话框。