de.altimos.util.translator.XmlTranslation.java Source code

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Here is the source code for de.altimos.util.translator.XmlTranslation.java

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/*
 * A Java Utility Library
 * 
 * Copyright (C) 2010 Jan Graichen <jg@altimos.de>
 *
 * 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.
 *
 * See the NOTICE file distributed along with this work for further
 * information.
 */
package de.altimos.util.translator;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Locale;
import java.util.MissingResourceException;

import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.input.SAXBuilder;

/**
 * Translation implementation that uses a xml file as source and
 * maps translation keys to tree structure.
 * 
 * @author Jan Graichen <jg@altimos.de>
 * @version $Id$
 */
public class XmlTranslation implements Translation {

    private HashMap<String, Element> roots = new HashMap<String, Element>();

    private String delimiter = "\\.";

    public XmlTranslation() {
        this("\\.");
    }

    public XmlTranslation(String delimiter) {
        this.delimiter = delimiter;
    }

    protected Element loadRoot(Translator translator, String locale, String domain) {
        if (domain.length() > 0 && locale.length() > 0) {
            domain += "_";
        }
        try {
            InputStream in = translator.getSource().getStream(domain + locale + ".xml");
            if (in != null) {
                SAXBuilder builder = new SAXBuilder();
                return builder.build(in).getRootElement();
            }
        } catch (IOException e) {
            throw new MissingResourceException(e.getMessage(), XmlTranslation.class.getSimpleName(), null);
        } catch (JDOMException e) {
            throw new MissingResourceException(e.getMessage(), XmlTranslation.class.getSimpleName(), null);
        }
        return null;
    }

    protected Element getRoot(Translator translator, String locale, String domain) {
        if (!roots.containsKey(locale)) {
            Element root = loadRoot(translator, locale, domain);
            roots.put(locale, root);
        }
        return roots.get(locale);
    }

    protected Element getElement(Translator translator, String key, Locale locale, String domain) {
        if (locale.getLanguage().length() > 0 && locale.getCountry().length() > 0
                && locale.getVariant().length() > 0) {
            Element root = getRoot(translator,
                    locale.getLanguage() + "_" + locale.getCountry() + "_" + locale.getVariant(), domain);
            Element e = getElement(root, key.split(delimiter), 0);
            if (e != null) {
                return e;
            }
        }

        if (locale.getLanguage().length() > 0 && locale.getCountry().length() > 0) {
            Element root = getRoot(translator, locale.getLanguage() + "_" + locale.getCountry(), domain);
            Element e = getElement(root, key.split(delimiter), 0);
            if (e != null) {
                return e;
            }
        }

        if (locale.getLanguage().length() > 0) {
            Element root = getRoot(translator, locale.getLanguage(), domain);
            Element e = getElement(root, key.split(delimiter), 0);
            if (e != null) {
                return e;
            }
        }

        Element root = getRoot(translator, "", domain);
        Element e = getElement(root, key.split(delimiter), 0);
        if (e != null) {
            return e;
        }
        throw new MissingTranslationException(
                "Translation for " + key + " cannot be found in " + domain + " for " + locale + ".",
                XmlTranslation.class.getSimpleName(), key);
    }

    protected Element getElement(Element e, String[] key, int offset) {
        if (offset == key.length || e == null) {
            return e;
        }

        if (e.getChild(key[offset]) != null) {
            return getElement(e.getChild(key[offset]), key, offset + 1);
        }
        return null;
    }

    @Override
    public String getString(Translator translator, String key, Locale locale, String domain, Object[] args) {
        Element e = getElement(translator, key.toLowerCase(), locale, domain);
        if (e != null) {
            return e.getTextTrim().replace("\\n", "\n");
        }
        return "";
    }

}