Groovy example source code file (VMPluginFactory.java)

This example Groovy source code file (VMPluginFactory.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

classloader, classloader, java4, java4, jdk5_classname_check, jdk5_plugin_name, jdk6_classname_check, jdk6_plugin_name, jdk7_classname_check, string, string, vmplugin, vmplugin, vmpluginfactory

The Groovy VMPluginFactory.java source code

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.groovy.vmplugin;

import org.codehaus.groovy.vmplugin.v4.Java4;

/**
 * factory class to get functionality based on the VM version.
 * The usage of this class is not for public use, only for the
 * runtime.
 * @author Jochen Theodorou
 */
public class VMPluginFactory {
    
    private static final String JDK5_CLASSNAME_CHECK = "java.lang.annotation.Annotation";
    private static final String JDK5_PLUGIN_NAME = "org.codehaus.groovy.vmplugin.v5.Java5";
    private static final String JDK6_CLASSNAME_CHECK = "javax.script.ScriptEngine";
    private static final String JDK6_PLUGIN_NAME = "org.codehaus.groovy.vmplugin.v6.Java6";
    private static final String JDK7_CLASSNAME_CHECK = "java.nio.file.FileRef";
    private static final String JDK7_PLUGIN_NAME = "org.codehaus.groovy.vmplugin.v7.Java7";
    private static VMPlugin plugin;
    static {
        try {
            // v6 plugin is the same as v5 but with some scripting stuff
            // so check below is good enough for now (can be true for JVM 5)
            ClassLoader loader = VMPluginFactory.class.getClassLoader();
            loader.loadClass(JDK7_CLASSNAME_CHECK);
            plugin = (VMPlugin) loader.loadClass(JDK7_PLUGIN_NAME).newInstance();
        } catch(Exception ex) {
            /* ignore */
        }
        if (plugin == null) {
            try {
                // v6 plugin is the same as v5 but with some scripting stuff
                // so check below is good enough for now (can be true for JVM 5)
                ClassLoader loader = VMPluginFactory.class.getClassLoader();
                loader.loadClass(JDK6_CLASSNAME_CHECK);
                plugin = (VMPlugin) loader.loadClass(JDK6_PLUGIN_NAME).newInstance();
            } catch (Exception ex) {
                /* ignore */
            }
        }
        if (plugin == null) {
            try {
                ClassLoader loader = VMPluginFactory.class.getClassLoader();
                loader.loadClass(JDK5_CLASSNAME_CHECK);
                plugin = (VMPlugin) loader.loadClass(JDK5_PLUGIN_NAME).newInstance();
            } catch(Exception ex) {
                plugin = new Java4();
            }
        }
    }
    
    public static VMPlugin getPlugin() {
        return plugin;
    }
    
}