io.wcm.devops.conga.generator.plugins.fileheader.XmlFileHeader.java Source code

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Here is the source code for io.wcm.devops.conga.generator.plugins.fileheader.XmlFileHeader.java

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/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2015 wcm.io
 * %%
 * 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.
 * #L%
 */
package io.wcm.devops.conga.generator.plugins.fileheader;

import java.io.IOException;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.lang3.StringUtils;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;

import com.google.common.collect.ImmutableList;

import io.wcm.devops.conga.generator.GeneratorException;
import io.wcm.devops.conga.generator.spi.FileHeaderPlugin;
import io.wcm.devops.conga.generator.spi.context.FileContext;
import io.wcm.devops.conga.generator.spi.context.FileHeaderContext;
import io.wcm.devops.conga.generator.util.FileUtil;

/**
 * Adds file headers to XML files.
 */
public final class XmlFileHeader implements FileHeaderPlugin {

    private final DocumentBuilder documentBuilder;
    private final Transformer transformer;

    /**
     * Plugin name
     */
    public static final String NAME = "xml";

    private static final String FILE_EXTENSION = "xml";

    /**
     * Constructor.
     */
    public XmlFileHeader() {
        try {
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            transformer = transformerFactory.newTransformer();
        } catch (ParserConfigurationException | TransformerConfigurationException ex) {
            throw new GeneratorException("Unable to initialize validator.", ex);
        }
    }

    @Override
    public String getName() {
        return NAME;
    }

    @Override
    public boolean accepts(FileContext file, FileHeaderContext context) {
        return FileUtil.matchesExtension(file, FILE_EXTENSION);
    }

    @Override
    public Void apply(FileContext file, FileHeaderContext context) {
        try {
            Document doc = documentBuilder.parse(file.getFile());

            // build XML comment and add it at first position
            Comment comment = doc.createComment("\n" + StringUtils.join(context.getCommentLines(), "\n") + "\n");
            doc.insertBefore(comment, doc.getChildNodes().item(0));

            // write file
            file.getFile().delete();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(file.getFile());
            transformer.transform(source, result);
        } catch (SAXException | IOException | TransformerException ex) {
            throw new GeneratorException("Unable to add file header to " + FileUtil.getCanonicalPath(file), ex);
        }
        return null;
    }

    @Override
    public FileHeaderContext extract(FileContext file) {
        try {
            Document doc = documentBuilder.parse(file.getFile());
            if (doc.getChildNodes().getLength() > 0) {
                Node firstNode = doc.getChildNodes().item(0);
                if (firstNode instanceof Comment) {
                    String comment = StringUtils.trim(((Comment) firstNode).getTextContent());
                    List<String> lines = ImmutableList.copyOf(StringUtils.split(comment, "\n"));
                    return new FileHeaderContext().commentLines(lines);
                }
            }
        } catch (SAXException | IOException ex) {
            throw new GeneratorException("Unable to parse file header from " + FileUtil.getCanonicalPath(file), ex);
        }
        return null;
    }

}