package test;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.swing.ProgressMonitor;
import javax.swing.ProgressMonitorInputStream;

public class ReadFile{
	private File target, output;
	
	public ReadFile(File target, File output) {
		this.target = target;
		this.output = output;
	}
	
	/*
	 * 這里需要設(shè)置 ProgressMonitor對(duì)象的最小值和最大值。
	 * 當(dāng)超過最大值時(shí)，進(jìn)度條正好結(jié)束。
	 * 需要手動(dòng)調(diào)用 setProgress 方法，更新進(jìn)度。
	 * 更新的方法有很多種，可以自己計(jì)算相對(duì)大小，這里我取一個(gè)簡(jiǎn)單的方法。
	 * 直接利用文件的大小并進(jìn)行累加。
	 * */
	public void readFile() throws InterruptedException {
		byte[] b = new byte[124];
		try(
			FileInputStream in = new FileInputStream(target);
			FileOutputStream out = new FileOutputStream(output);
			ProgressMonitorInputStream pmi = new ProgressMonitorInputStream(null, "讀取", in)) {
			ProgressMonitor monitor = pmi.getProgressMonitor();
			monitor.setMinimum(0);
			monitor.setMaximum((int) (target.length()));
			int progress = 124;
			int sum = 0;
			while (in.read(b) != -1) {
				out.write(b);
			//此處代碼在控制臺(tái)打印當(dāng)前源文件。
			//	String s = new String(b);
			//	System.out.println(s);
				Thread.sleep(1000);
				sum += progress;
				monitor.setProgress(sum);
			}
		} catch(IOException e) {
			e.printStackTrace();
		}
	}
}

package test;

import java.io.File;

public class Test {
	public static void main(String[] args) throws InterruptedException {
		ReadFile read = new ReadFile(new File("./src/test/ReadFile.java"), new File("./output.java"));
		read.readFile();
	}
}