/*

* 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 com.nokia.microedition.m2g.connection;

import java.io.IOException;

import javax.microedition.m2g.ExternalResourceHandler;

import com.nokia.microedition.m2g.connection.common.M2GConnectionPolicyImpl;

/**

 * Connection factory

 */

public class M2GConnectionFactory

{

    //--------------------------------------------------

    // STATIC CONSTANTS

    //--------------------------------------------------

    public static final String COMMON_PROTOCOL =

        "common";

    public static final String FILE_PROTOCOL =

        "file";

    public static final String CONNECTION_BASE_PACKAGE =

        "com.nokia.microedition.m2g.connection.";

    public static final String CONNECTION_PROXY_CLASS_NAME =

        ".M2GConnectionProxyImpl";

    //--------------------------------------------------

    // METHODS

    //--------------------------------------------------

    /**

     * Ctor

     */

    private M2GConnectionFactory()

    {

    }

    /**

     * Create a connection proxy.

     * If a url is not absolute or if it's beginig with

     * the slash mark then a resource is considered to be opened from a jar file.

     * @param aUrl Locator

     * @return Connection proxy

       * @throws IOException if an io error occurs

       * @throws NullPointerException if the locator is null.

       * @throws IllegalArgumentException if the locator is of unsupported type.

     */

    public static M2GConnectionProxy create(String aUrl) throws IOException

    {

        try

        {

            M2GConnectionProxy proxy = null;

            M2GUrlTokenizer tokenizer = new M2GUrlTokenizer(aUrl);

            // If a url begins with the slash mark then

            // a resource is tryed to open from a jar file.

            if (!M2GUrlTokenizer.isAbsolutURL(aUrl) ||

                    tokenizer.beginWithSlash())

            {

                proxy = new M2GConnectionProxy();

            }

            else

            {

                Class proxyClass =

                    Class.forName(parseClassName(tokenizer.getProtocol()));

                proxy = (M2GConnectionProxy)proxyClass.newInstance();

            }

            proxy.open(tokenizer);

            return proxy;

        }

        catch (InstantiationException e)

        {

            throw new IllegalArgumentException("Internal error: " + e.getMessage());

        }

        catch (IllegalAccessException e)

        {

            throw new IllegalArgumentException("Internal error: " + e.getMessage());

        }

        catch (ClassNotFoundException e)

        {

            throw new IllegalArgumentException("Internal error: " + e.getMessage());

        }

    }

    /**

     * Get default external resource handler

     * @param aUrl URL

     * @return external resource handler

     */

    public static ExternalResourceHandler getExternalResourceHandler(String aUrl)

    {

        return new M2GDefaultExternalResourceHandler(aUrl);

    }

    /**

     * Resolve external resource URL

     * @param aTokenizer Tokenizer

     * @param aUrl URL

     * @return connection proxy

     * @throws IOException

     */

    public static M2GConnectionProxy resolveExternalResourceUrl(

        M2GUrlTokenizer aTokenizer, String aUrl) throws IOException

    {

        // Check if the URL is relative.

        if (!M2GUrlTokenizer.isAbsolutURL(aUrl))

        {

            if (aTokenizer.getBaseUrl() != null)

            {

                aUrl = aTokenizer.resolveUrl(aUrl);

            }

        }

        return M2GConnectionFactory.create(aUrl);

    }

    /**

     * Get default policy

     * @return Connection policy

     */

    public static M2GConnectionPolicy getDefaultPolicy()

    {

        return new M2GConnectionPolicyImpl();

    }

    /**

       * Parses a connection proxy class name.

       * @param aProtocol Protocol

       * @return Connection proxy class name

       */

    private static String parseClassName(String aProtocol)

    {

        if (aProtocol.equals(FILE_PROTOCOL))

        {

            return

                CONNECTION_BASE_PACKAGE + FILE_PROTOCOL + CONNECTION_PROXY_CLASS_NAME;

        }

        else

        {

            return

                CONNECTION_BASE_PACKAGE + COMMON_PROTOCOL + CONNECTION_PROXY_CLASS_NAME;

        }

    }

}