/*

* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package javax.microedition.io;

import java.security.Permission;

import java.security.PermissionCollection;

/**

 * This class represents access rights to connections via the "http" protocol.

 * A HttpProtocolPermission consists of a URI string but no actions list.

 * <p>

 * The URI string specifies a data resource accessible via http. It takes the

 *following general form:

 * <p>

 * http://{host}[:{portspec}][{pathname}][?{query}][#{fragment}]

 * <p>

 * (See RFC 3986 for more information.) The value of the {host} field must be a

 * symbolic hostname, a literal IPv4 address or a literal IPv6 address, as

 * specified by RFC 3986. If the {host} string is a DNS name, an asterisk may

 * appear in the leftmost position to indicate a match of 1 or more entire

 * domain labels. Partial domain label matches are not permitted, therefore

 * "*.sun.com" is valid, but "*sun.com" is not. An asterisk by itself matches

 * all hosts.

 * <p>

 * The {portspec} string takes the following form:

 * <p>

 * portnumber | -portnumber | portnumber-[portnumber] | "*" | empty string

 * <p>

 * A {portspec} specification of the form "N-" (where N is a port number)

 * signifies all ports numbered N and above, while a specification of the form

 * "-N" indicates all ports numbered N and below. A single asterisk in the

 * place of the {portspec} field matches all ports; therefore, the URI

 * "http://*:*" matches http connections to all hosts on all ports. If the

 * {portspec} field is omitted, default port 80 is assumed.

 *

 * @see Connector.open(java.lang.String)

 * @see "javax.microedition.io.HttpConnection" in MIDP 3.0 Specification

 *

 * @author Nokia Corporation

 * @version 1.0

 */

public final class HttpProtocolPermission

        extends GCFPermission

{

    /**

     * Creates a new HttpProtocolPermission with the specified URI as its name.

     * The URI string must conform to the specification given above, and is

     * normalized to facilitate subsequent comparisons.

     *

     * @param uri the URI string.

     * @throws IllegalArgumentException if uri is malformed.

     * @throws NullPointerException if uri is null.

     */

    public HttpProtocolPermission(String uri)

    {

        super(uri);

    }

    /**

     * Checks if this HttpProtocolPermission object "implies" the specified

     * permission.

     * <p>

     * Because the {host} field of the permission URI may indicate an

     * individual host by means of either a symbolic hostname or an IP address,

     * a thorough evaluation of the implies relation between two

     * HttpProtocolPermission objects requires the underlying platform to be

     * able to transform symbolic hostnames into IP addresses (via address

     * lookup) and vice-versa (via name lookup). Either service may be

     * unavailable on a given platform. As a result, the comparison of URI

     * strings from two permissions can only be best-effort. For each

     * HttpProtocolPermission constructed with a URI that contains a {host}

     * field, the implementation will attempt to determine both the

     * fully-qualified domain name (the "canonical name") and the IP

     * address(es) of the host. However, either value may be unknown.

     * <p>

     * To determine whether this object implies another permission, p, this

     * method first ensures that all of the following are true (and returns

     * false if any of them are not):

     * <ul>

     * <li>p is an instanceof HttpProtocolPermission, and</li>

     * <li>p's port range is included in this port range.</li>

     * </ul>

     * Then implies checks each of the following, in order, and for each

     * returns true if the stated condition is true:

     * <ul>

     * <li>If this object has a single IP address and one of p's IP addresses

     * is equal to this object's IP address.</li>

     * <li>If this object has a wildcard domain (such as *.sun.com), and p's

     * absolute name (the name with any preceding * removed) ends with this

     * object's aboslute name. For example, *.sun.com implies *.eng.sun.com.

     * </li>

     * <li>If this object has multiple IP addresses, and one of this object's

     * IP addresses equals one of p's IP addresses.</li>

     * <li>If this object's canonical name equals p's canonical name.</li>

     * </ul>

     * If none of the above are true, implies returns false.

     * <p>

     * Note that the {pathname}, {query} and {fragment} components are not

     * used when evaluating the 'implies' relation.

     *

     * @param p the permission to check against.

     * @return true if the specified permission is implied by this object,

     *        false if not.

     */

    public boolean implies(Permission p)

    {

        if (p instanceof HttpProtocolPermission)

        {

            return true;

        }

        return false;

    }

    /**

     * Checks two HttpProtocolPermission objects for equality.

     *

     * @param obj the object we are testing for equality with this object.

     * @return true if obj is a HttpProtocolPermission and has the same URI

     *         string as this HttpProtocolPermission object.

     */

    public boolean equals(Object obj)

    {

        return true;

    }

    /**

     * Returns the hash code value for this object.

     *

     * @return a hash code value for this object.

     */

    public int hashCode()

    {

        return 0;

    }

    /**

     * Returns the canonical string representation of the actions, which

     * currently is the empty string "", since there are no actions

     * defined for HttpProtocolPermission.

     *

     * @return the empty string "".

     */

    public String getActions()

    {

        return "";

    }

    /**

     * Returns a new PermissionCollection for storing

     * HttpProtocolPermission objects.

     * <p>

     * HttpProtocolPermission objects must be stored in a manner that allows

     * them to be inserted into the collection in any order, but that also

     * enables the PermissionCollection implies method to be implemented in

     * an efficient (and consistent) manner.

     *

     * @return a new PermissionCollection suitable for storing

     *         HttpProtocolPermission objects.

     */

    public PermissionCollection newPermissionCollection()

    {

        return null;

    }

}