autobind/integrations/enterprise/src/main/java/org/apache/onami/autobind/enterprise/features/WebFilterBindingFeature.java

package org.apache.onami.autobind.enterprise.features;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.
 */

import java.lang.annotation.Annotation;
import java.util.Map;
import java.util.logging.Logger;

import javax.inject.Singleton;
import javax.servlet.Filter;
import javax.servlet.annotation.WebFilter;

import org.apache.onami.autobind.install.BindingStage;
import org.apache.onami.autobind.scanner.features.BindingScannerFeature;

import com.google.inject.servlet.ServletModule;


@Singleton
public class WebFilterBindingFeature extends BindingScannerFeature {
	private static Logger LOGGER = Logger.getLogger(WebFilterBindingFeature.class.getName());
	
	@Override
	public BindingStage accept(Class<Object> annotatedClass, Map<String, Annotation> annotations) {
		if (annotations.containsKey(WebFilter.class.getName())) {
			return BindingStage.BINDING;
		}
		return BindingStage.IGNORE;
	}

	@Override
	public void process(final Class<Object> annotatedClass,
			final Map<String, Annotation> annotations) {
		final WebFilter annotation = (WebFilter) annotations.get(WebFilter.class.getName());
		
		String[] patterns = annotation.value();
		final String value;
		final String[] values;
		if(patterns.length > 0){
			value = resolver.resolve(patterns[0]);
			if(patterns.length > 1){
				values = new String[patterns.length-1];
				
				for(int i=1;i<patterns.length;i++){
					values[i-1] = resolver.resolve(patterns[i]);
				}				
			}else{
				values = new String[0];
			}
		}else{
			// failure
			LOGGER.info("Ignoring Filter \""+annotatedClass+"\", because no Values for URLs were specified.");
			return;
		}
		
		_binder.install(new ServletModule(){
			@Override
			protected void configureServlets() {
				filter(value, values).through(annotatedClass.asSubclass(Filter.class));
			}
		});
	}
}