CodeWriter.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2011 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.mule.devkit.model.code;

import org.mule.devkit.model.code.util.EncoderFactory;
import org.mule.devkit.model.code.util.UnicodeEscapeWriter;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.CharsetEncoder;

/**
 * Receives generated code and writes to the appropriate storage.
 *
 * @author Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
public abstract class CodeWriter {

    /**
     * Called by CodeModel to store the specified file.
     * The callee must allocate a storage to store the specified file.
     * <p/>
     * <p/>
     * The returned stream will be closed before the next file is
     * stored. So the callee can assume that only one OutputStream
     * is active at any given time.
     *
     * @param pkg      The package of the file to be written.
     * @param fileName File name without the path. Something like
     *                 "Foo.java" or "Bar.properties"
     */
    public abstract OutputStream openBinary(Package pkg, String fileName) throws IOException;

    /**
     * Called by CodeModel to store the specified file.
     * The callee must allocate a storage to store the specified file.
     * <p/>
     * <p/>
     * The returned stream will be closed before the next file is
     * stored. So the callee can assume that only one OutputStream
     * is active at any given time.
     *
     * @param pkg      The package of the file to be written.
     * @param fileName File name without the path. Something like
     *                 "Foo.java" or "Bar.properties"
     */
    public Writer openSource(Package pkg, String fileName) throws IOException {
        final OutputStreamWriter bw = new OutputStreamWriter(openBinary(pkg, fileName));

        // create writer
        try {
            return new UnicodeEscapeWriter(bw) {
                // can't change this signature to Encoder because
                // we can't have Encoder in method signature
                private final CharsetEncoder encoder = EncoderFactory.createEncoder(bw.getEncoding());

                @Override
                protected boolean requireEscaping(int ch) {
                    // control characters
                    if (ch < 0x20 && " \t\r\n".indexOf(ch) == -1) {
                        return true;
                    }
                    // check ASCII chars, for better performance
                    if (ch < 0x80) {
                        return false;
                    }

                    return !encoder.canEncode((char) ch);
                }
            };
        } catch (Throwable t) {
            return new UnicodeEscapeWriter(bw);
        }
    }

    /**
     * Called by CodeModel at the end of the process.
     */
    public abstract void close() throws IOException;
}