ScannerModule.java

/**
 * Copyright (C) 2010 Daniel Manzke <daniel.manzke@googlemail.com>
 *
 * 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 de.devsurf.injection.guice.scanner;

import java.io.IOException;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.inject.Inject;

import com.google.inject.Binder;
import com.google.inject.Module;

import de.devsurf.injection.guice.annotations.Bind;
import de.devsurf.injection.guice.annotations.GuiceModule;
import de.devsurf.injection.guice.install.InstallationContext;
import de.devsurf.injection.guice.scanner.features.BindingScannerFeature;
import de.devsurf.injection.guice.scanner.features.ScannerFeature;

/**
 * The ScannerModule will be injected with a ClasspathScanner and the needed
 * Annotation Listeners will be added. The attached Listeners will install all
 * Modules annotated with {@link GuiceModule} and bind all Beans annotated with
 * {@link Bind}.
 * 
 * @author Daniel Manzke
 * 
 */
public class ScannerModule implements Module {
	public static String LINE_SEPARATOR = System.getProperty("line.separator");
	private Logger _logger = Logger.getLogger(ScannerModule.class.getName());
	@Inject
	private ClasspathScanner _scanner;
	@Inject
	private Set<ScannerFeature> _listeners;
	@Inject
	private InstallationContext _context;

	@Override
	public void configure(Binder binder) {
		if (_logger.isLoggable(Level.INFO)) {
			StringBuilder builder = new StringBuilder();
			builder.append(_scanner.getClass().getName()+" is using following Scanner Features: ").append(LINE_SEPARATOR);
			for (ScannerFeature listener : _listeners) {
				builder.append(listener.getClass().getName()).append(LINE_SEPARATOR);
			}
			_logger.log(Level.INFO, builder.toString());
		}
		for (ScannerFeature listener : _listeners) {
			if (listener instanceof BindingScannerFeature) {
				((BindingScannerFeature) listener).setBinder(binder);
				if (_logger.isLoggable(Level.FINE)) {
					_logger.fine("Binding AnnotationListeners " + listener.getClass().getName());
				}
			}
		}
		try {
			_scanner.scan();
		} catch (IOException e) {
			_logger.log(Level.SEVERE,
				"Failure while Scanning the Classpath for Classes with Annotations.", e);
		}
		try {
			_context.process();
		} catch (Exception e) {
			_logger.log(Level.SEVERE, "Failure while executing the collected Tasks.", e);
		}
	}
}