useradminpermission.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

    private static boolean match_credential(char[] a, int i) {
        return ((a[i - 9] == 'c' || a[i - 9] == 'C')
                && (a[i - 8] == 'r' || a[i - 8] == 'R')
                && (a[i - 7] == 'e' || a[i - 7] == 'E')
                && (a[i - 6] == 'd' || a[i - 6] == 'D')
                && (a[i - 5] == 'e' || a[i - 5] == 'E')
                && (a[i - 4] == 'n' || a[i - 4] == 'N')
                && (a[i - 3] == 't' || a[i - 3] == 'T')
                && (a[i - 2] == 'i' || a[i - 2] == 'I')
                && (a[i - 1] == 'a' || a[i - 1] == 'A') && (a[i - 0] == 'l' || a[i - 0] == 'L'));
    }

    /**
     * Checks if this <tt>UserAdminPermission</tt> object &quot;implies&quot;
     * the specified permission.
     * <P>
     * More specifically, this method returns <tt>true</tt> if:
     * <p>
     * <ul>
     * <li> <i>p</i> is an instanceof <tt>UserAdminPermission</tt>,
     * <li> <i>p</i>'s actions are a proper subset of this object's actions,
     * and
     * <li> <i>p</i>'s name is implied by this object's name. For example,
     * &quot;java.*&quot; implies &quot;java.home&quot;.
     * </ul>
     * 
     * @param p
     *            the permission to check against.
     * 
     * @return <tt>true</tt> if the specified permission is implied by this
     *         object; <tt>false</tt> otherwise.
     */
    public boolean implies(Permission p) {
        if (p instanceof UserAdminPermission) {
            UserAdminPermission target = (UserAdminPermission) p;
            return (// Check that the we have the requested action
            ((target.action_mask & action_mask) == target.action_mask)
                    &&
                    // If the target action mask is ACTION_NONE, it must be an
                    // admin permission, and then we must be that too
                    (target.action_mask != ACTION_NONE || action_mask == ACTION_NONE) &&
            // Check that name name matches
            super.implies(p));
        }
        return (false);
    }

    /**
     * Returns the canonical string representation of the actions, separated by
     * comma.
     * 
     * @return the canonical string representation of the actions.
     */
    public String getActions() {
        if (actions == null) {
            StringBuffer sb = new StringBuffer();
            boolean comma = false;

            if ((action_mask & ACTION_CHANGE_CREDENTIAL) == ACTION_CHANGE_CREDENTIAL) {
                sb.append(CHANGE_CREDENTIAL);
                comma = true;
            }

            if ((action_mask & ACTION_CHANGE_PROPERTY) == ACTION_CHANGE_PROPERTY) {
                if (comma)
                    sb.append(',');
                sb.append(CHANGE_PROPERTY);
                comma = true;
            }

            if ((action_mask & ACTION_GET_CREDENTIAL) == ACTION_GET_CREDENTIAL) {
                if (comma)
                    sb.append(',');
                sb.append(GET_CREDENTIAL);
            }

            actions = sb.toString();
        }

        return (actions);
    }

    /**
     * Returns a new <tt>PermissionCollection</tt> object for storing
     * <tt>UserAdminPermission</tt> objects.
     * 
     * @return a new <tt>PermissionCollection</tt> object suitable for storing
     *         <tt>UserAdminPermission</tt> objects.
     */
    public PermissionCollection newPermissionCollection() {
        return (new UserAdminPermissionCollection());
    }

    /**
     * Checks two <tt>UserAdminPermission</tt> objects for equality. Checks
     * that <tt>obj</tt> is a <tt>UserAdminPermission</tt>, and has the
     * same name and actions as this object.
     * 
     * @param obj
     *            the object to be compared for equality with this object.
     * 
     * @return <tt>true</tt> if <tt>obj</tt> is a
     *         <tt>UserAdminPermission</tt> object, and has the same name and
     *         actions as this <tt>UserAdminPermission</tt> object.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return (true);
        }
        if (obj instanceof UserAdminPermission) {
            UserAdminPermission uap = (UserAdminPermission) obj;
            return ((action_mask == uap.action_mask) && getName().equals(
                    uap.getName()));
        }
        return (false);
    }

    /**
     * Returns the hash code of this <tt>UserAdminPermission</tt> object.
     */
    public int hashCode() {
        return (getName().hashCode() ^ getActions().hashCode());
    }

    /**
     * Returns the current action mask. Used by the
     * <tt>UserAdminPermissionCollection</tt> class.
     * 
     * @return the actions mask.
     */
    int getMask() {
        return (action_mask);
    }

    /**
     * writeObject is called to save the state of this object to a stream. The
     * actions are serialized, and the superclass takes care of the name.
     */

    private synchronized void writeObject(java.io.ObjectOutputStream s)
            throws IOException {
        // Write out the actions. The superclass takes care of the name
        // call getActions to make sure actions field is initialized
        if (actions == null)
            getActions();
        s.defaultWriteObject();
    }

    /*
     * Restores this object from a stream (i.e., deserializes it).
     */
    private synchronized void readObject(java.io.ObjectInputStream ois)
            throws IOException, ClassNotFoundException {
        ois.defaultReadObject();
        init(getMask(actions));
    }

    /**
     * Returns a string describing this <tt>UserAdminPermission</tt> object.
     * This string must be in <tt>PermissionInfo</tt> encoded format.
     * 
     * @return The <tt>PermissionInfo</tt> encoded string for this
     *         <tt>UserAdminPermission</tt> object.
     * TODO@see org.osgi.service.permissionadmin.PermissionInfo#getEncoded
     */
    public String toString() {
        if (description == null) {
            StringBuffer sb = new StringBuffer();

            sb.append('(');
            sb.append(getClass().getName());
            sb.append(" \"");
            sb.append(getName());
            String actions = getActions();
            if (actions.length() > 0) {
                sb.append("\" \"");
                sb.append(actions);
            }
            sb.append("\")");

            description = sb.toString();
        }

        return (description);
    }

}

/**
 * A <tt>UserAdminPermissionCollection</tt> stores a set of
 * <tt>UserAdminPermission</tt> permissions.
 */
final class UserAdminPermissionCollection extends PermissionCollection {

    private static final long serialVersionUID = 1L;

    /**
     * Table of permissions.
     * 
     * @serial
     */
    private Hashtable permissions;

    /**
     * Boolean saying if "*" is in the collection.
     * 
     * @serial
     */
    private boolean all_allowed;

    /**
     * Creates an empty <tt>UserAdminPermissionCollection</tt> object.
     */
    public UserAdminPermissionCollection() {
        permissions = new Hashtable();
        all_allowed = false;
    }

    /**
     * Adds the given permission to this <tt>UserAdminPermissionCollection</tt>.
     * The key for the hash is the name.
     * 
     * @param permission
     *            the <tt>Permission</tt> object to add.
     * 
     * @throws IllegalArgumentException
     *             If the given permission is not a <tt>UserAdminPermission</tt>
     * @throws SecurityException
     *             If this <tt>UserAdminPermissionCollection</tt> object has
     *             been marked readonly
     */
    public void add(Permission permission) {
        if (!(permission instanceof UserAdminPermission))
            throw new IllegalArgumentException("Invalid permission: "
                    + permission);
        if (isReadOnly()) {
            throw new SecurityException("Attempt to add a Permission to a "
                    + "readonly PermissionCollection");
        }

        UserAdminPermission uap = (UserAdminPermission) permission;
        String name = uap.getName();

        UserAdminPermission existing = (UserAdminPermission) permissions
                .get(name);

        if (existing != null) {
            int oldMask = existing.getMask();
            int newMask = uap.getMask();
            if (oldMask != newMask) {
                permissions.put(name, new UserAdminPermission(name, oldMask
                        | newMask));
            }
        } else {
            permissions.put(name, permission);
        }

        if (!all_allowed) {
            if (name.equals("*"))
                all_allowed = true;
        }
    }

    /**
     * Checks to see if this <tt>PermissionCollection</tt> implies the given
     * permission.
     * 
     * @param permission
     *            the <tt>Permission</tt> object to check against
     * 
     * @return true if the given permission is implied by this
     *         <tt>PermissionCollection</tt>, false otherwise.
     */
    public boolean implies(Permission permission) {
        if (!(permission instanceof UserAdminPermission)) {
            return (false);
        }

        UserAdminPermission uap = (UserAdminPermission) permission;
        UserAdminPermission x;

        int desired = uap.getMask();
        int effective = 0;

        // Short circuit if the "*" Permission was added.
        // desired can only be ACTION_NONE when name is "admin".
        if (all_allowed && desired != UserAdminPermission.ACTION_NONE) {
            x = (UserAdminPermission) permissions.get("*");
            if (x != null) {
                effective |= x.getMask();
                if ((effective & desired) == desired) {
                    return (true);
                }
            }
        }

        // strategy:
        // Check for full match first. Then work our way up the
        // name looking for matches on a.b.*
        String name = uap.getName();

        x = (UserAdminPermission) permissions.get(name);

        if (x != null) {
            // we have a direct hit!
            effective |= x.getMask();
            if ((effective & desired) == desired) {
                return (true);
            }
        }

        // work our way up the tree...
        int last;

        int offset = name.length() - 1;

        while ((last = name.lastIndexOf(".", offset)) != -1) {
            name = name.substring(0, last + 1) + "*";
            x = (UserAdminPermission) permissions.get(name);

            if (x != null) {
                effective |= x.getMask();
                if ((effective & desired) == desired) {
                    return (true);
                }
            }
            offset = last - 1;
        }

        // we don't have to check for "*" as it was already checked
        // at the top (all_allowed), so we just return false
        return (false);
    }

    /**
     * Returns an enumeration of all the <tt>UserAdminPermission</tt> objects
     * in the container.
     * 
     * @return an enumeration of all the <tt>UserAdminPermission</tt> objects.
     */
    public Enumeration elements() {
        return (permissions.elements());
    }
}