/*
* Copyright 2003-2013 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.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.*;
import static org.codehaus.groovy.runtime.DefaultGroovyMethodsSupport.closeQuietly;
/**
* A module extension scanner is responsible for searching classpath modules,
* loading metadata from module descriptors, then perform custom tasks for each
* module.
*
* This class was introduced as a fix for GROOVY-6008
*
* @author Cedric Champeau
* @since 2.1.2
*/
public class ExtensionModuleScanner {
public static final String MODULE_META_INF_FILE = "META-INF/services/org.codehaus.groovy.runtime.ExtensionModule";
private final ExtensionModuleListener listener;
private final ClassLoader classLoader;
public ExtensionModuleScanner(final ExtensionModuleListener listener, final ClassLoader loader) {
this.listener = listener;
this.classLoader = loader;
}
public void scanClasspathModules() {
try {
Enumeration<URL> resources = classLoader.getResources(MODULE_META_INF_FILE);
while (resources.hasMoreElements()) {
URL url = resources.nextElement();
scanExtensionModuleFromMetaInf(url);
}
} catch (IOException e) {
// DO NOTHING
}
}
private void scanExtensionModuleFromMetaInf(final URL metadata) {
Properties properties = new Properties();
InputStream inStream = null;
try {
inStream = metadata.openStream();
properties.load(inStream);
} catch (IOException e) {
throw new GroovyRuntimeException("Unable to load module META-INF descriptor", e);
} finally {
closeQuietly(inStream);
}
scanExtensionModuleFromProperties(properties);
}
public void scanExtensionModuleFromProperties(final Properties properties) {
StandardPropertiesModuleFactory factory = new StandardPropertiesModuleFactory();
ExtensionModule module = factory.newModule(properties, classLoader);
listener.onModule(module);
}
public interface ExtensionModuleListener {
void onModule(ExtensionModule module);
}
}