set Posix Permissions - Java File Path IO

Description

set Posix Permissions
Demo Code

/*-//from   ww w .j  a  va 2 s  .c om
 * Copyright (C) 2014 Erik Larsson
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
//package com.java2s;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import java.util.HashSet;
import java.util.Set;

public class Main {
    public static void setPosixPermissions(String path, boolean ownerRead,
            boolean ownerWrite, boolean ownerExecute, boolean groupRead,
            boolean groupWrite, boolean groupExecute, boolean othersRead,
            boolean othersWrite, boolean othersExecute)
            throws ClassNotFoundException, NoSuchMethodException,
            IllegalAccessException, IllegalArgumentException,
            InvocationTargetException, NoSuchFieldException {
        Class<?> fileSystemsClass = Class
                .forName("java.nio.file.FileSystems");
        Class<?> fileSystemClass = Class
                .forName("java.nio.file.FileSystem");
        Class<?> pathClass = Class.forName("java.nio.file.Path");
        Class<?> posixFileAttributeViewClass = Class
                .forName("java.nio.file.attribute.PosixFileAttributeView");
        Class<?> filesClass = Class.forName("java.nio.file.Files");
        Class<?> linkOptionClass = Class
                .forName("java.nio.file.LinkOption");
        Class<?> posixFilePermissionClass = Class
                .forName("java.nio.file.attribute.PosixFilePermission");

        /* java.nio.file.FileSystem defaultFileSystem =
                   java.nio.file.FileSystems.getDefault(); */
        Method fileSystemsGetDefaultMethod = fileSystemsClass
                .getMethod("getDefault");
        Object defaultFileSystemObject = fileSystemsGetDefaultMethod
                .invoke(null);

        /* java.nio.file.Path p = defaultFileSystem.getPath(path); */
        Method fileSystemGetPathMethod = fileSystemClass.getMethod(
                "getPath", String.class, String[].class);
        Object pObject = fileSystemGetPathMethod.invoke(
                defaultFileSystemObject, path, new String[0]);

        /* java.nio.file.attribute.PosixFileAttributeView attrView =
         *         java.nio.file.Files.getFileAttributeView(p,
         *         java.nio.file.attribute.PosixFileAttributeView.class,
         *         java.nio.file.LinkOption.NOFOLLOW_LINKS); */
        Field noFollowLinksField = linkOptionClass
                .getField("NOFOLLOW_LINKS");
        Object noFollowLinksObject = noFollowLinksField.get(null);

        Object linkOptionsArray = Array.newInstance(linkOptionClass, 1);
        Array.set(linkOptionsArray, 0, noFollowLinksObject);

        Method getFileAttributeViewMethod = filesClass.getMethod(
                "getFileAttributeView", pathClass, Class.class,
                linkOptionsArray.getClass());
        Object attrViewObject = getFileAttributeViewMethod.invoke(null,
                pObject, posixFileAttributeViewClass, linkOptionsArray);

        if (attrViewObject == null) {
            /* No PosixFileAttributeView available. Platform does not support
             * POSIX attributes. Just return quietly here. */
            return;
        }

        HashSet<Object> perms = new HashSet<Object>();

        if (ownerRead) {
            Field curField = posixFilePermissionClass
                    .getField("OWNER_READ");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (ownerWrite) {
            Field curField = posixFilePermissionClass
                    .getField("OWNER_WRITE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (ownerExecute) {
            Field curField = posixFilePermissionClass
                    .getField("OWNER_EXECUTE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (groupRead) {
            Field curField = posixFilePermissionClass
                    .getField("GROUP_READ");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (groupWrite) {
            Field curField = posixFilePermissionClass
                    .getField("GROUP_WRITE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (groupExecute) {
            Field curField = posixFilePermissionClass
                    .getField("GROUP_EXECUTE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (othersRead) {
            Field curField = posixFilePermissionClass
                    .getField("OTHERS_READ");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (othersWrite) {
            Field curField = posixFilePermissionClass
                    .getField("OTHERS_WRITE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        if (othersExecute) {
            Field curField = posixFilePermissionClass
                    .getField("OTHERS_EXECUTE");
            Object curObject = curField.get(null);
            perms.add(curObject);
        }

        /* attrView.setPermissions(perms); */
        Method posixFileAttributeViewSetPermissionMethod = posixFileAttributeViewClass
                .getMethod("setPermissions", Set.class);
        try {
            posixFileAttributeViewSetPermissionMethod.invoke(
                    attrViewObject, perms);
        } catch (InvocationTargetException ex) {
            final Throwable cause = ex.getCause();
            if (cause instanceof ClassNotFoundException) {
                throw (ClassNotFoundException) cause;
            } else if (cause instanceof NoSuchMethodException) {
                throw (NoSuchMethodException) cause;
            } else if (cause instanceof IllegalAccessException) {
                throw (IllegalAccessException) cause;
            } else if (cause instanceof IllegalArgumentException) {
                throw (IllegalArgumentException) cause;
            } else if (cause instanceof InvocationTargetException) {
                throw (InvocationTargetException) cause;
            } else if (cause instanceof NoSuchFieldException) {
                throw (NoSuchFieldException) cause;
            } else if (cause instanceof RuntimeException) {
                throw (RuntimeException) cause;
            } else {
                throw ex;
            }
        }
    }
}
set Posix Permissions - Java File Path IO

Description

Demo Code

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