src/main/java/freemarker/ext/dom/Transform.java

/*
 * Copyright (c) 2003 The Visigoth Software Society. All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
 *    project contributors may be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact visigoths@visigoths.org.
 *
 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software Society.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */
 
package freemarker.ext.dom;


import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Locale;
import java.util.StringTokenizer;

import freemarker.core.Environment;
import freemarker.template.Configuration;
import freemarker.template.Template;

/**
 * A class that contains a main() method for command-line invocation
 * of a FreeMarker XML transformation.
 */
public class Transform {
    
    private File inputFile, ftlFile, outputFile;
    private String encoding;
    private Locale locale;
    private Configuration cfg; 
    
    /**
     * A convenient main() method for command-line invocation.
     */
    static public void main(String[] args) {
        try {
            Transform proc = transformFromArgs(args);
            proc.transform();
        } catch (IllegalArgumentException iae) {
            System.err.println(iae.getMessage());
            usage();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     * @param inputFile The file from which to read the XML input
     * @param ftlFile  The file containing the template
     * @param outputFile The file to which to output. If this is null, we use stdout.
     * @param locale The locale to use. If this is null, we use the platform default.
     * @param encoding The character encoding to use for output, if this is null, we use the platform default
     */
    
    Transform(File inputFile, File ftlFile, File outputFile, Locale locale, String encoding) throws IOException {
        if (encoding == null) {
            encoding = System.getProperty("file.encoding");
        }
        if (locale ==  null) {
            locale = Locale.getDefault();
        }
        this.encoding = encoding;
        this.locale = locale;
        this.inputFile = inputFile;
        this.ftlFile = ftlFile;
        this.outputFile = outputFile;
        File ftlDirectory = ftlFile.getAbsoluteFile().getParentFile();
        cfg = new Configuration();
        cfg.setDirectoryForTemplateLoading(ftlDirectory);
    }
    
    /**
     * Performs the transformation.
     */
    void transform() throws Exception {
        String templateName = ftlFile.getName();
        Template template = cfg.getTemplate(templateName, locale);
        NodeModel rootNode = NodeModel.parse(inputFile);
        OutputStream outputStream = System.out;
        if (outputFile != null) {
            outputStream = new FileOutputStream(outputFile);
        }
        Writer outputWriter = new OutputStreamWriter(outputStream, encoding);
        try {
            template.process(null, outputWriter, null, rootNode);
        } finally {
            if (outputFile != null)
                outputWriter.close();
        }
    }
    
    static Transform transformFromArgs(String[] args) throws IOException {
        int i=0;
        String input = null, output=null, ftl = null, loc = null, enc = null; 
        while (i<args.length) {
            String dashArg = args[i++];
            if (i>=args.length) {
                throw new IllegalArgumentException("");
            }
            String arg = args[i++];
            if (dashArg.equals("-in")) {
                if (input != null) {
                    throw new IllegalArgumentException("The input file should only be specified once");
                }
                input = arg;
            } else if (dashArg.equals("-ftl")) {
                if (ftl != null) {
                    throw new IllegalArgumentException("The ftl file should only be specified once");
                }
                ftl = arg;
            } else if (dashArg.equals("-out")) {
                if (output != null) {
                    throw new IllegalArgumentException("The output file should only be specified once");
                }
                output = arg;
            } else if (dashArg.equals("-locale")) {
                if (loc != null) {
                    throw new IllegalArgumentException("The locale should only be specified once");
                }
                loc = arg;
            } else if (dashArg.equals("-encoding")) {
                if (enc != null) {
                    throw new IllegalArgumentException("The encoding should only be specified once");
                }
                enc = arg;
            } else {
                throw new IllegalArgumentException("Unknown input argument: " + dashArg);
            }
        }
        if (input == null) {
            throw new IllegalArgumentException("No input file specified.");
        }
        if (ftl == null) {
            throw new IllegalArgumentException("No ftl file specified.");
        }
        File inputFile = new File(input).getAbsoluteFile();
        File ftlFile = new File(ftl).getAbsoluteFile();
        if (!inputFile.exists()) {
            throw new IllegalArgumentException("Input file does not exist: " + input);
        }
        if (!ftlFile.exists()) {
            throw new IllegalArgumentException("FTL file does not exist: " + ftl);
        }
        if (!inputFile.isFile() || !inputFile.canRead()) {
            throw new IllegalArgumentException("Input file must be a readable file: " + input);
        }
        if (!ftlFile.isFile() || !ftlFile.canRead()) {
            throw new IllegalArgumentException("FTL file must be a readable file: " + ftl);
        }
        File outputFile = null;
        if (output != null) {
            outputFile = new File(output).getAbsoluteFile();
            File outputDirectory = outputFile.getParentFile();
            if (!outputDirectory.exists() || !outputDirectory.canWrite()) {
                throw new IllegalArgumentException("The output directory must exist and be writable: " + outputDirectory);
            }
        }
        Locale locale = Locale.getDefault();
        if (loc != null) {
            locale = localeFromString(loc);
        }
        return new Transform(inputFile, ftlFile, outputFile, locale, enc);
    }
    
    static Locale localeFromString(String ls) {
        if (ls == null) ls = "";
        String lang="", country="", variant="";
        StringTokenizer st = new StringTokenizer(ls, "_-,");
        if (st.hasMoreTokens()) {
            lang = st.nextToken();
            if (st.hasMoreTokens()) {
                country = st.nextToken();
                if (st.hasMoreTokens()) {
                    variant = st.nextToken();
                }
            }
            return new Locale(lang, country, variant);
        } else {
            return Locale.getDefault();
        }
    }
    
    static void usage() {
        System.err.println("Usage: java freemarker.ext.dom.Transform -in <xmlfile> -ftl <ftlfile> [-out <outfile>] [-locale <locale>] [-encoding <encoding>]");
        // Security: prevents shutting down the container from a template:
        if (Environment.getCurrentEnvironment() == null) {
            System.exit(-1);
        }
    }
}