com
  └─sedaier
      └─calcdir
          ├─service
          │  │  IDirSizeCalc.java
          │  │
          │  └─impl
          │         DirSizeCalcByForkJoinPoolImpl.java
          │
          ├─test
          │      Test.java
          │
          └─tool
                 OutputFileUtils.java //日志輸出工具類(lèi)

package com.sedaier.calcdir.service.impl;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveTask;

import com.sedaier.calcdir.service.IDirSizeCalc;
import com.sedaier.calcdir.tool.OutputFileUtils;

public class DirSizeCalcByForkJoinPoolImpl implements IDirSizeCalc {
	
	@Override
	public long getSize(final File file, final File log) {
		ForkJoinPool forkJoinPool = new ForkJoinPool();
		return forkJoinPool.invoke(new FileSizeFinder(file, log));
	}

	@SuppressWarnings("serial")
	private static class FileSizeFinder extends RecursiveTask<Long> {
		final File file;
		final File log;

		FileSizeFinder(final File theFile, final File theLog) {
			file = theFile;
			log = theLog;
		}

		@Override
		public Long compute() {
			long size = 0;
			if (file.isFile()) {
				size = file.length();
				OutputFileUtils.write(log, file);
			} else {
				final File[] children = file.listFiles();
				if (children != null) {
					List<ForkJoinTask<Long>> tasks = new ArrayList<ForkJoinTask<Long>>();
					for (final File child : children) {
						if (child.isFile()) {
							size += child.length();
							OutputFileUtils.write(log, child);
						} else {
							tasks.add(new FileSizeFinder(child, log));
						}
					}
					for (final ForkJoinTask<Long> task : invokeAll(tasks)) {
						size += task.join();
					}
				}
			}
			return size;
		}
	}
}

package com.sedaier.calcdir.service;

import java.io.File;

public interface IDirSizeCalc {
	long getSize(final File file, final File log);
}

package com.sedaier.calcdir.test;

import java.io.File;

import com.sedaier.calcdir.service.IDirSizeCalc;
import com.sedaier.calcdir.service.impl.DirSizeCalcByForkJoinPoolImpl;
import com.sedaier.calcdir.tool.OutputFileUtils;

public class Test {
	public static void main(final String[] args) {
		String dirPath = "C:\\Windows";
		String log = "C:\\Users\\Administrator\\Desktop\\log.log";
		File file = new File(dirPath);
		File logFile = new File(log);

		calcDirSize(file, logFile, new DirSizeCalcByForkJoinPoolImpl());
		OutputFileUtils.distory();
	}

	private static void calcDirSize(File file, File log, IDirSizeCalc dirSizeCalc) {
		dirSizeCalc.getSize(file, log);
	}
}

package com.sedaier.calcdir.tool;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Calendar;

public class OutputFileUtils {

	public static int time = 0;
	//buffer刷信息時(shí)間
	public static int overtime = 100;
	//避免重復(fù)初始化
	public static boolean flag = false;
	public static FileWriter out = null;
	public static BufferedWriter bw = null;
	//昨天
	public static long day;
	//用于計(jì)算日期 -1 當(dāng)前日期往前一天,-2 當(dāng)前日期往前兩天
	public static int amount = -1;
	
	static {
		//初始化日期
		Calendar instance = Calendar.getInstance();
		instance.add(Calendar.DAY_OF_MONTH, amount);
		day = instance.getTimeInMillis();
	}
	
	public static void write(final File log, File file) {
		
		try {
			if (!flag && !log.exists()) {
				log.createNewFile();
				flag = true;
			}
			if(out == null || bw == null) {
				out = new FileWriter (log);
				bw = new BufferedWriter(out);
			}
			long lastModified = file.lastModified();
			if(lastModified > day) {
				bw.write(String.format("%s===大小=%d===時(shí)間=%tF",file.getAbsolutePath(),file.length()/1000000,lastModified));
				bw.newLine();
			}
			time++;
			if(time > overtime) {
				bw.flush();
				time = 0 ;
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public static void distory() {
		try {
			bw.close();
			out.close();
			System.out.println("關(guān)閉成功!");
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}