代码

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.PosixFilePermission;
import java.util.Set;
public class Main {

public static void main(String[] args) throws IOException {
        File file = new File("/home");
        for (File listFile : file.listFiles()) {
            Path path = Paths.get(listFile.getAbsolutePath());
            Set<PosixFilePermission> set = Files.getPosixFilePermissions(path);
            int group = 0, own = 0, other = 0;
            for (PosixFilePermission permission : set) {
                switch (permission) {
                    case GROUP_READ:
                        group += 4;
                        break;
                    case GROUP_WRITE:
                        group += 2;
                        break;
                    case GROUP_EXECUTE:
                        group += 1;
                        break;
                    case OWNER_READ:
                        own += 4;
                        break;
                    case OWNER_WRITE:
                        own += 2;
                        break;
                    case OWNER_EXECUTE:
                        own += 1;
                        break;
                    case OTHERS_READ:
                        other += 4;
                        break;
                    case OTHERS_WRITE:
                        other += 2;
                        break;
                    case OTHERS_EXECUTE:
                        other += 1;
                        break;
                }
            }
            int code = own * 100 + group * 10 + other;
            System.out.println(code);
        }
    }

结果

可以用stat -c %a来验证结果

image.png

image.png