org.culturegraph.mf.jdom.StreamToJDomDocument.java Source code

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Here is the source code for org.culturegraph.mf.jdom.StreamToJDomDocument.java

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/*
 * Copyright 2013, 2014 Deutsche Nationalbibliothek
 *
 * 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.culturegraph.mf.jdom;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.regex.Pattern;

import org.culturegraph.mf.commons.ResourceUtil;
import org.culturegraph.mf.framework.FluxCommand;
import org.culturegraph.mf.framework.MetafactureException;
import org.culturegraph.mf.framework.ObjectReceiver;
import org.culturegraph.mf.framework.StreamReceiver;
import org.culturegraph.mf.framework.annotations.Description;
import org.culturegraph.mf.framework.annotations.In;
import org.culturegraph.mf.framework.annotations.Out;
import org.culturegraph.mf.framework.helpers.DefaultStreamPipe;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.Namespace;

/**
 * Converts a stream into a {@link Document}.
 *
 * @author Markus Geipel
 */
@Description("Converts a stream into a JDom document.")
@In(StreamReceiver.class)
@Out(Document.class)
@FluxCommand("to-jdom-document")
public final class StreamToJDomDocument extends DefaultStreamPipe<ObjectReceiver<Document>> {

    private static final String ATTRIBUTE_MARKER = "~";
    private static final Pattern NAMESPACE_DELIMITER = Pattern.compile(":", Pattern.LITERAL);
    private static final String XML = "xml";

    private Document document;
    private Element currentElement;
    private final String rootTagName;
    private final Map<String, Namespace> namespaces = new HashMap<String, Namespace>();

    public StreamToJDomDocument(final String rootTagName, final String namespaceProperties) {
        this.rootTagName = rootTagName;
        namespaces.put(XML, Namespace.getNamespace(XML, "http://www.w3.org/XML/1998/namespace"));
        final Properties properties;
        try {
            properties = ResourceUtil.loadProperties(namespaceProperties);
        } catch (IOException e) {
            throw new MetafactureException("Cannot load namespaces list", e);
        }
        for (Entry<Object, Object> entry : properties.entrySet()) {
            namespaces.put(entry.getKey().toString(),
                    Namespace.getNamespace(entry.getKey().toString(), entry.getValue().toString()));
        }
    }

    @Override
    public void startRecord(final String identifier) {
        assert !isClosed();
        currentElement = createElement(rootTagName);
        for (Namespace namespace : namespaces.values()) {
            currentElement.addNamespaceDeclaration(namespace);
        }
        document = new Document(currentElement);
    }

    @Override
    public void startEntity(final String name) {
        assert !isClosed();
        final Element parent = currentElement;
        currentElement = createElement(name);
        parent.addContent(currentElement);
    }

    private Element createElement(final String name) {
        final String[] parts = NAMESPACE_DELIMITER.split(name);
        if (parts.length == 2) {
            return new Element(parts[1], getNamespace(parts[0]));
        }
        return new Element(name);
    }

    private Namespace getNamespace(final String name) {
        final Namespace namespace = namespaces.get(name);
        if (namespace == null) {
            throw new IllegalArgumentException("Namespace " + name + " not registered");
        }
        return namespace;
    }

    @Override
    public void endEntity() {
        assert !isClosed();
        currentElement = currentElement.getParentElement();
    }

    @Override
    public void literal(final String name, final String value) {
        assert !isClosed();
        if (name.isEmpty()) {
            currentElement.addContent(value);
        } else if (name.startsWith(ATTRIBUTE_MARKER)) {
            final String[] parts = NAMESPACE_DELIMITER.split(name);
            if (parts.length == 2) {
                currentElement.setAttribute(parts[1], value, getNamespace(parts[0].substring(1)));
            } else {
                currentElement.setAttribute(name.substring(1), value);
            }

        } else {
            final Element temp = createElement(name);
            currentElement.addContent(temp);
            temp.setText(value);
        }
    }

    @Override
    public void endRecord() {
        assert !isClosed();
        getReceiver().process(document);
    }

}