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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.tools.visualvm.application.jvm;

import com.sun.tools.visualvm.application.Application;
import com.sun.tools.visualvm.core.model.ModelFactory;
import com.sun.tools.visualvm.core.model.ModelProvider;

/**
 * The JVMFactory class is a factory class for getting the
 * {@link Jvm} representation  for the {@link Application}.
 * 
 * @author Tomas Hurka
 */
public final class JvmFactory extends ModelFactory<Jvm,Application> implements ModelProvider<Jvm,Application> {

    private static JvmFactory jvmFactory;

    private JvmFactory() {
    }
    
    /**
     * Getter for the default version of the JvmFactory.
     * @return instance of {@link JvmFactory}.
     */
    public static synchronized JvmFactory getDefault() {
        if (jvmFactory == null) {
            jvmFactory = new JvmFactory();
            jvmFactory.registerProvider(jvmFactory);
        }
        return jvmFactory;
    }
    
    /**
     * Factory method for obtaining {@link Jvm} for {@link Application}. Note that there
     * is only one instance of {@link Jvm} for a concrete application. This {@link Jvm}
     * instance is cached.
     * @param app application 
     * @return {@link Jvm} instance which encapsulates application's JVM.
     */
    public static Jvm getJVMFor(Application app) {
        return getDefault().getModel(app);
    }
    
    /**
     * Default {@link ModelProvider} implementation, which creates 
     * dummy {@link Jvm} instances. If you want to extend JvmFactory use 
     * {@link JvmFactory#registerProvider(ModelProvider )} to register the new instances
     * of {@link ModelProvider} for the different types of {@link Application}.
     * @param app application
     * @return dummy instance of {@link Jvm}
     */
    public Jvm createModelFor(Application app) {
        return new DefaultJvm();
    }
}
