core/src/main/java/org/jclouds/util/Modules2.java

/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds licenses this file
 * to you 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.jclouds.util;

import static com.google.common.base.Splitter.on;
import static com.google.common.collect.Iterables.concat;
import static com.google.common.collect.Iterables.transform;

import java.util.Properties;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.inject.Module;



/**
 * 
 * 
 * @author Adrian Cole
 */
public class Modules2 {

   public static Iterable<Module> modulesFromCommaDelimitedString(String moduleClasses) {
      Iterable<Module> modules = ImmutableSet.of();
      if (moduleClasses != null) {
         Iterable<String> transformer = ImmutableList.copyOf(on(',').split(moduleClasses));
         modules = transform(transformer, new Function<String, Module>() {
   
            @Override
            public Module apply(String from) {
               try {
                  return (Module) ClassLoadingUtils.loadClass(Modules2.class, from).newInstance();
               } catch (InstantiationException e) {
                  throw new RuntimeException("error instantiating " + from, e);
               } catch (IllegalAccessException e) {
                  throw new RuntimeException("error instantiating " + from, e);
               }
            }
   
         });
      }
      return modules;
   }

   public static Iterable<Module> modulesForProviderInProperties(String providerName, Properties props) {
      return concat(modulesFromProperty(props, "jclouds.modules"),
            modulesFromProperty(props, providerName + ".modules"));
   }

   public static Iterable<Module> modulesFromProperty(Properties props, String property) {
      return modulesFromCommaDelimitedString(props.getProperty(property, null));
   }

}