Full control over file attributes is available in Java 7, as part of the "new" New IO facility (NIO.2). For example, POSIX permissions can be set with setPosixFilePermissions().
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.attribute.PosixFilePermission;
import java.util.HashSet;
import java.util.Set;
public class FilePermissions {
/**
* File Permissions Java Example using File and PosixFilePermission
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
File file = new File("/Users/pankaj/temp.txt");
//set application user permissions to 455
file.setExecutable(false);
file.setReadable(false);
file.setWritable(true);
//change permission to 777 for all the users
//no option for group and others
file.setExecutable(true, false);
file.setReadable(true, false);
file.setWritable(true, false);
//using PosixFilePermission to set file permissions 777
Set<PosixFilePermission> perms = new HashSet<PosixFilePermission>();
//add owners permission
perms.add(PosixFilePermission.OWNER_READ);
perms.add(PosixFilePermission.OWNER_WRITE);
perms.add(PosixFilePermission.OWNER_EXECUTE);
//add group permissions
perms.add(PosixFilePermission.GROUP_READ);
perms.add(PosixFilePermission.GROUP_WRITE);
perms.add(PosixFilePermission.GROUP_EXECUTE);
//add others permissions
perms.add(PosixFilePermission.OTHERS_READ);
perms.add(PosixFilePermission.OTHERS_WRITE);
perms.add(PosixFilePermission.OTHERS_EXECUTE);
Files.setPosixFilePermissions(Paths.get("/Users/pankaj/run.sh"), perms);
}
}
From above example, it’s clear that PosixFilePermission provides more options and code is more readable. If you are using Java 7, you should use it for setting file permissions in java.