RestServiceProcessor.java

/*
 * Copyright 2015 cruxframework.org.
 * 
 * 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.cruxframework.crux.core.annotation.processor;

import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;

import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.annotation.processing.SupportedOptions;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.TypeElement;
import javax.tools.Diagnostic;
import javax.tools.FileObject;

import org.cruxframework.crux.core.server.rest.annotation.RestService;

/**
 * @author Thiago da Rosa de Bustamante
 *
 */
@SupportedAnnotationTypes("org.cruxframework.crux.core.server.rest.annotation.RestService")
@SupportedOptions(
	{
		CruxAnnotationProcessor.CRUX_RUN_APT,
		CruxAnnotationProcessor.CRUX_APT_INCREMENTAL
	})
public class RestServiceProcessor extends CruxAnnotationProcessor
{
	private static final String CRUX_REST_MAP_FILE = "META-INF/crux-rest";
	private Properties restMap;
	private boolean previousSourcesLoaded = false;

	public RestServiceProcessor()
	{
		restMap = new Properties();
	}
	
	@Override
	public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv)
	{
		if(!runAPT())
		{
			return true;
		}
		
		try
		{
			boolean incremental = isIncremental();
			if (incremental && !previousSourcesLoaded)
			{
				InputStream inputStream = getResourceFileStream(CRUX_REST_MAP_FILE);
				if (inputStream != null)
				{
					restMap.load(inputStream);
					inputStream.close();
				}
				previousSourcesLoaded = true;
			}
			for (Element elem : roundEnv.getElementsAnnotatedWith(RestService.class))
			{
				RestService restService = elem.getAnnotation(RestService.class);
				if (elem.getKind() == ElementKind.CLASS || elem.getKind() == ElementKind.INTERFACE) 
				{
					String restServiceAlias = restService.value();
					String restServiceClassName = ((TypeElement) elem).getQualifiedName().toString();
					if (incremental && restMap.containsValue(restServiceClassName))
					{
						for (Entry<Object, Object> entry: restMap.entrySet())
						{
							if (entry.getValue().equals(restServiceClassName))
							{
								restMap.remove(entry.getKey());
								break;
							}
						}
					}
					restMap.put(restServiceAlias, restServiceClassName);
				}
			}

			if (roundEnv.processingOver())
			{
				FileObject newRestFile = createResourceFile(CRUX_REST_MAP_FILE);
				OutputStream outputStream = newRestFile.openOutputStream();
				restMap.store(outputStream, "Crux REST Services implementations");
				outputStream.close();
			}
		}
		catch (Exception e)
		{
			processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, e.getMessage());
		}

		return true;
	}
}