/*

* 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 com.nokia.mj.impl.rt.support;

import com.nokia.mj.impl.rt.JvmPort;

/**

 * Provides JVM utilities for Java API implementations to use. Some of these

 * utilities hide differences between CLDC and CDC configurations and some

 * provide completely non-standard access to JVM features and to process memory.

 *<p>

 * Example how to load a system library

 * <pre>

 * package com.nokia.mj.impl.mypackage;

 *

 * import com.nokia.mj.impl.rt.support;

 *      public void myClass()

 *      {

 *          public void myMethod()

 *          {

 *              //loads the system library.

 *              Jvm.loadSystemLibrary("my_system_library");

 *

 *              //my implementation...

 *          }

 *      }

 *</pre>

 * @author Nokia Corporation

 * @version 1.0

 */

public class Jvm

{

    /**

     * Loads the system library specified by the libName argument.

     * <p>

     * This method uses <code>System.loadLibrary</code> in CDC based

     * configuration while in CLDC a proprieatary API is used.

     * @param libName The name of the library.

     */

    public static void loadSystemLibrary(String libName)

    {

        JvmPort.getInstance().loadSystemLibrary(libName);

    }

    /**

     * JAVADOCS ARE UNDER CONSTRUCTION!!

     * <p>

     * Returns the Class object associated with the class or interface with the

     * given string name.

     * @param name A fully qualified name of the desired class.

     * @return class object representing the desired class .

     */

    public static Class loadApplicationClass(String name)

    throws ClassNotFoundException

    {

        return JvmPort.getInstance().loadApplicationClass(name);

    }

    /**

     * Marks the given thread as either a daemon thread or a user thread

     * This can only be done before the Thread starts running.

     * @param thread The thread to be modified.

     * @param daemon If true, marks the given thread as a daemon thread.

     * @throws IllegalThreadStateException if the Thread has already been

     * started.

     * @throws SecurityException if the caller is not in the boot class path.

     */

    public static void setThreadAsDaemon(Thread thread, boolean daemon)

    throws IllegalThreadStateException, SecurityException

    {

        JvmPort.getInstance().setThreadAsDaemon(thread, daemon);

    }

    /**

     * JAVADOCS ARE UNDER CONSTRUCTION!!

     * <p>

     * Gets a NativeMemoryBlock. NativeMemoryBlock provids a way

     * read the whole content of resource in jar file into native memory

     * buffer. The content is not copien into Java side - only pointer

     * and size of the data is usable in the Java side.

     *

     * @param jarPath If jarPath is null then the resource is searched from

     * the classpath - like in normal class.getResourceAsStream. If it is

     * provided then it can be any Jar file availble in the file system.

     * @param resName Name of the desired resource

     *

     */

    public static NativeMemoryBlock getResourceAsNativeMemory(String jarPath,

            String resName)

    {

        return JvmPort.getInstance().getResourceAsNativeMemory(jarPath, resName);

    }

}