org.codehaus.groovy.runtime.m12n.MetaInfExtensionModule Maven / Gradle / Ivy

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/*
 * Copyright 2003-2009 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.runtime.m12n;

import groovy.lang.GroovyRuntimeException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Properties;
import java.util.logging.Logger;

/**
 * A {@link SimpleExtensionModule} implementation which reads extension classes
 * metadata from META-INF.
 *
 * @since 2.0.0
 *
 * @author Cedric Champeau
 */
public class MetaInfExtensionModule extends SimpleExtensionModule {
    private final static Logger LOG = Logger.getLogger(MetaInfExtensionModule.class.getName());

    public final static String MODULE_INSTANCE_CLASSES_KEY = "extensionClasses";
    public final static String MODULE_STATIC_CLASSES_KEY = "staticExtensionClasses";

    private final List instanceExtensionClasses;
    private final List staticExtensionClasses;

    @Override
    public List getInstanceMethodsExtensionClasses() {
        return instanceExtensionClasses;
    }

    @Override
    public List getStaticMethodsExtensionClasses() {
        return staticExtensionClasses;
    }

    private MetaInfExtensionModule(final String moduleName, final String moduleVersion, final List instanceExtensionClasses, final List staticExtensionClasses) {
        super(moduleName, moduleVersion);
        this.instanceExtensionClasses = instanceExtensionClasses;
        this.staticExtensionClasses = staticExtensionClasses;
    }

    public static MetaInfExtensionModule newModule(final Properties properties, final ClassLoader loader) {
        String name = properties.getProperty(PropertiesModuleFactory.MODULE_NAME_KEY);
        if (name==null) throw new GroovyRuntimeException("Module file hasn't set the module name using key ["+PropertiesModuleFactory.MODULE_NAME_KEY+"]");
        String version = properties.getProperty(PropertiesModuleFactory.MODULE_VERSION_KEY);
        if (version==null) throw new GroovyRuntimeException("Module file hasn't set the module version using key ["+PropertiesModuleFactory.MODULE_VERSION_KEY+"]");
        String[] extensionClasses = properties.getProperty(MODULE_INSTANCE_CLASSES_KEY, "").trim().split("[,; ]");
        String[] staticExtensionClasses = properties.getProperty(MODULE_STATIC_CLASSES_KEY, "").trim().split("[,; ]");
        List instanceClasses = new ArrayList(extensionClasses.length);
        List staticClasses = new ArrayList(staticExtensionClasses.length);
        List errors = new LinkedList();
        for (String extensionClass : extensionClasses) {
            try {
                extensionClass = extensionClass.trim();
                if (extensionClass.length()>0) {
                    instanceClasses.add(loader.loadClass(extensionClass));
                }
            } catch (ClassNotFoundException e) {
                errors.add(extensionClass);
            }
        }
        for (String extensionClass : staticExtensionClasses) {
            try {
                extensionClass = extensionClass.trim();
                if (extensionClass.length()>0) {
                    staticClasses.add(loader.loadClass(extensionClass));
                }
            } catch (ClassNotFoundException e) {
                errors.add(extensionClass);
            }
        }
        if (!errors.isEmpty()) {
            for (String error : errors) {
                LOG.warning("Module ["+name+"] - Unable to load extension class ["+error+"]");
            }
        }
        return new MetaInfExtensionModule(name, version, instanceClasses, staticClasses);
    }

}