利用 Java 檢查檔案或目錄的大小 (Use Java to check size of a file or a directory)

import java.io.File

public static long filesize(File file){
    long size = 0L;
    if (file.isFile()){
        size = file.length();
    } else if (file.isDirectory()){
        File[] nFiles = file.listFiles();
        for (File nFile : nFiles){
            size += filesize(nFile);
        }
    }
    return size;
}