NoJMergeAcceleoFileWriter.java

/**
 * Optimus, framework for Model Transformation
 *
 * Copyright (C) 2013 Worldline or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
package net.atos.optimus.m2t.java.core.internal;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.StringWriter;
import java.io.Writer;

import org.eclipse.acceleo.engine.generation.writers.AbstractAcceleoWriter;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.emf.common.EMFPlugin;

/**
 * Wraps a buffered FileWriter for generation with Acceleo. Note that this can
 * also be used to create a Writer that will previously merge the content of an
 * existing file with the new content through JMerge.
 * 
 * This class is based on the AcceleoFileWriter, except that the JMerge
 * invocation was removed
 * 
 * @author Maxence Vanbésien (mvaawl@gmail.com)
 * @since 1.0
 */
public final class NoJMergeAcceleoFileWriter extends AbstractAcceleoWriter {

	/** Keeps a reference to the target file's absolute path. */
	private final String targetPath;
	private String selectedCharset;

	/**
	 * Constructs a buffered file writer around the given file. The file will be
	 * created with the default System encoding.
	 * 
	 * @param target
	 *            File in which this writer will append text.
	 * @param appendMode
	 *            Tells us wether the former content of the file should be
	 *            deleted.
	 * @throws IOException
	 *             Thrown if the target file doesn't exist and cannot be
	 *             created.
	 */
	public NoJMergeAcceleoFileWriter(File target, boolean appendMode) throws IOException {
		delegate = new BufferedWriter(new FileWriter(target, appendMode));
		targetPath = target.getAbsolutePath();
	}

	/**
	 * Constructs a buffered file writer around the given file and tells which
	 * encoding should be used to generate the file.
	 * 
	 * @param target
	 *            File in which this writer will append text.
	 * @param appendMode
	 *            Tells us wether the former content of the file should be
	 *            deleted.
	 * @param charset
	 *            Encoding that should be used to create the target file.
	 * @throws IOException
	 *             Thrown if the target file doesn't exist and cannot be
	 *             created.
	 */
	public NoJMergeAcceleoFileWriter(File target, boolean appendMode, String charset) throws IOException {
		final OutputStream fileOutputStream = new FileOutputStream(target, appendMode);
		final OutputStreamWriter fileWriter = new OutputStreamWriter(fileOutputStream, charset);
		delegate = new BufferedWriter(fileWriter);
		targetPath = target.getAbsolutePath();
	}

	/**
	 * Constructs a writer that will use JMerge to merge the content of the file
	 * existing at path <em>filePath</em> with its new content. Note that the
	 * file will be written with the default System encoding if using this.
	 * 
	 * @param filePath
	 *            Path of the file this writer will contain the content of.
	 */
	public NoJMergeAcceleoFileWriter(String filePath) {
		delegate = new StringWriter(DEFAULT_BUFFER_SIZE);
		targetPath = filePath;
	}

	/**
	 * Constructs a writer that will use JMerge to merge the content of the file
	 * existing at path <em>filePath</em> with its new content.
	 * 
	 * @param filePath
	 *            Path of the file this writer will contain the content of.
	 * @param charset
	 *            Encoding that's to be used to create the file with the merged
	 *            content.
	 */
	public NoJMergeAcceleoFileWriter(String filePath, String charset) {
		this(filePath);
		selectedCharset = charset;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.acceleo.engine.generation.writers.AbstractAcceleoWriter#close()
	 */
	@Override
	public void close() throws IOException {
		if (!EMFPlugin.IS_ECLIPSE_RUNNING || this.delegate instanceof BufferedWriter) {
			delegate.close();
		} else {
			Writer writer = null;
			OutputStream fileOutputStream = null;
			OutputStreamWriter fileWriter = null;
			try {
				if (selectedCharset == null) {
					writer = new BufferedWriter(new FileWriter(new File(targetPath)));
				} else {
					fileOutputStream = new FileOutputStream(new File(targetPath));
					fileWriter = new OutputStreamWriter(fileOutputStream, selectedCharset);
					writer = new BufferedWriter(fileWriter);
				}
				writer.append(toString());
				writer.flush();
			} catch (Exception e) {
				Activator
						.getDefault()
						.getLog()
						.log(new Status(IStatus.ERROR, Activator.PLUGIN_ID,
								"An exception occurred while writing to writer", e));
			} finally {
				if (writer != null) {
					writer.close();
				}
				if (fileWriter != null) {
					fileWriter.close();
				}
				if (fileOutputStream != null) {
					fileOutputStream.close();
				}
			}
		}
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.acceleo.engine.generation.writers.AbstractAcceleoWriter#getTargetPath()
	 */
	@Override
	public String getTargetPath() {
		return targetPath;
	}
}