Java 深度优先和广度优先 计算文件夹大小

1.深度优先(递归)

public class Demo
{
    public static long size = 0;
 
    private static void getSize(File[] fileArr)
    {
        if (null == fileArr || fileArr.length <= 0)//部分文件夹 无权限访问，返回null
        {
            return;
        }
        for (File file : fileArr)
        {
            if (file.isFile())
            {
                size += file.length();
            }
            if (file.isDirectory())
            {
                getSize(file.listFiles());
            }
        }
    }
 
    public static void main(String[] args)
    {
        long start = System.currentTimeMillis();
        
        File file = new File("D:\\");
        getSize(file.listFiles());
        System.out.println(file.getPath() + "---" + size + "字节");
        
        
        long end = System.currentTimeMillis();
        long elapsed = end - start;
        System.out.println("一共花了：" + elapsed + " 毫秒");
    }
}

2.广度优先

public class Directory
{
    public static LinkedList<File> files = new LinkedList<>();
 
    public static void put(File folder)
    {
        File[] fileArr=folder.listFiles();
        if (null == fileArr || fileArr.length <= 0) //某些文件夹无权限访问，会返回null
        {
            return;
        }
        for (File file : fileArr)
        {
            files.add(file);
        }
    }
 
    public static void main(String[] args)
    {
 
        long start = System.currentTimeMillis();
 
        
        long size = 0;
        File file = new File("D:\\");
        files.add(file);
        while (true)
        {
            if (files.isEmpty())
                break;
            File fileTemp = files.getLast();
            if (fileTemp.isFile())
            {
                size += fileTemp.length();
                files.removeLast();
            }
            if (fileTemp.isDirectory())
            {
                put(files.removeLast());
            }
        }
        System.out.println(file.getPath() + "---" + size + "字节");
        
        
        long end = System.currentTimeMillis();
        long elapsed = end - start;
        System.out.println("一共花了：" + elapsed + " 毫秒");
    }
}