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Diffstat (limited to 'src/java/org/apache/fop/util/XMLResourceBundle.java')
| -rw-r--r-- | src/java/org/apache/fop/util/XMLResourceBundle.java | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/src/java/org/apache/fop/util/XMLResourceBundle.java b/src/java/org/apache/fop/util/XMLResourceBundle.java new file mode 100644 index 000000000..1b320816b --- /dev/null +++ b/src/java/org/apache/fop/util/XMLResourceBundle.java @@ -0,0 +1,398 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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. + */ + +/* $Id$ */ + +package org.apache.fop.util; + +import java.io.IOException; +import java.io.InputStream; +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.Enumeration; +import java.util.Hashtable; +import java.util.Locale; +import java.util.Map; +import java.util.MissingResourceException; +import java.util.Properties; +import java.util.ResourceBundle; +import java.util.Stack; + +import javax.xml.transform.Transformer; +import javax.xml.transform.TransformerException; +import javax.xml.transform.sax.SAXResult; +import javax.xml.transform.sax.SAXTransformerFactory; +import javax.xml.transform.stream.StreamSource; + +import org.xml.sax.Attributes; +import org.xml.sax.SAXException; +import org.xml.sax.helpers.DefaultHandler; + +import org.apache.xmlgraphics.util.QName; + +/** + * This class is a ResourceBundle that loads its contents from XML files instead of properties + * files (like PropertiesResourceBundle). + * <p> + * The XML format for this resource bundle implementation is the following + * (the same as Apache Cocoon's XMLResourceBundle): + * <pre> + * <catalogue xml:lang="en"> + * <message key="key1">Message <br/> Value 1</message> + * <message key="key2">Message <br/> Value 1</message> + * ... + * </catalogue> + * </pre> + */ +public class XMLResourceBundle extends ResourceBundle { + + //Note: Some code here has been copied and adapted from Apache Harmony! + + private Properties resources = new Properties(); + + private Locale locale; + + private static SAXTransformerFactory tFactory + = (SAXTransformerFactory)SAXTransformerFactory.newInstance(); + + /** + * Creates a resource bundle from an InputStream. + * @param in the stream to read from + * @throws IOException if an I/O error occurs + */ + public XMLResourceBundle(InputStream in) throws IOException { + try { + Transformer transformer = tFactory.newTransformer(); + StreamSource src = new StreamSource(in); + SAXResult res = new SAXResult(new CatalogueHandler()); + transformer.transform(src, res); + } catch (TransformerException e) { + throw new IOException("Error while parsing XML resource bundle: " + e.getMessage()); + } + } + + /** + * Gets a resource bundle using the specified base name, default locale, and class loader. + * @param baseName the base name of the resource bundle, a fully qualified class name + * @param loader the class loader from which to load the resource bundle + * @return a resource bundle for the given base name and the default locale + * @throws MissingResourceException if no resource bundle for the specified base name can be + * found + * @see java.util.ResourceBundle#getBundle(String) + */ + public static ResourceBundle getXMLBundle(String baseName, ClassLoader loader) + throws MissingResourceException { + return getXMLBundle(baseName, Locale.getDefault(), loader); + } + + /** + * Gets a resource bundle using the specified base name, locale, and class loader. + * @param baseName the base name of the resource bundle, a fully qualified class name + * @param locale the locale for which a resource bundle is desired + * @param loader the class loader from which to load the resource bundle + * @return a resource bundle for the given base name and locale + * @throws MissingResourceException if no resource bundle for the specified base name can be + * found + * @see java.util.ResourceBundle#getBundle(String, Locale, ClassLoader) + */ + public static ResourceBundle getXMLBundle(String baseName, Locale locale, ClassLoader loader) + throws MissingResourceException { + if (loader == null) { + throw new NullPointerException("loader must not be null"); + } + if (baseName == null) { + throw new NullPointerException("baseName must not be null"); + } + + ResourceBundle bundle; + if (!locale.equals(Locale.getDefault())) { + bundle = handleGetXMLBundle(baseName, "_" + locale, false, loader); + if (bundle != null) { + return bundle; + } + } + bundle = handleGetXMLBundle(baseName, "_" + Locale.getDefault(), true, loader); + if (bundle != null) { + return bundle; + } + throw new MissingResourceException( + baseName + " (" + locale + ")", baseName + '_' + locale, null); + } + + static class MissingBundle extends ResourceBundle { + public Enumeration getKeys() { + return null; + } + + public Object handleGetObject(String name) { + return null; + } + } + + private static final ResourceBundle MISSING = new MissingBundle(); + private static final ResourceBundle MISSINGBASE = new MissingBundle(); + + private static Map cache = new java.util.WeakHashMap(); + //<Object, Hashtable<String, ResourceBundle>> + + private static ResourceBundle handleGetXMLBundle(String base, String locale, + boolean loadBase, final ClassLoader loader) { + XMLResourceBundle bundle = null; + String bundleName = base + locale; + Object cacheKey = loader != null ? (Object) loader : (Object) "null"; + Hashtable loaderCache; //<String, ResourceBundle> + synchronized (cache) { + loaderCache = (Hashtable)cache.get(cacheKey); + if (loaderCache == null) { + loaderCache = new Hashtable(); + cache.put(cacheKey, loaderCache); + } + } + ResourceBundle result = (ResourceBundle)loaderCache.get(bundleName); + if (result != null) { + if (result == MISSINGBASE) { + return null; + } + if (result == MISSING) { + if (!loadBase) { + return null; + } + String extension = strip(locale); + if (extension == null) { + return null; + } + return handleGetXMLBundle(base, extension, loadBase, loader); + } + return result; + } + + final String fileName = bundleName.replace('.', '/') + ".xml"; + InputStream stream = (InputStream)AccessController + .doPrivileged(new PrivilegedAction() { + public Object run() { + return loader == null + ? ClassLoader.getSystemResourceAsStream(fileName) + : loader.getResourceAsStream(fileName); + } + }); + if (stream != null) { + try { + try { + bundle = new XMLResourceBundle(stream); + } finally { + stream.close(); + } + bundle.setLocale(locale); + } catch (IOException e) { + throw new MissingResourceException(e.getMessage(), base, null); + } + } + + String extension = strip(locale); + if (bundle != null) { + if (extension != null) { + ResourceBundle parent = handleGetXMLBundle(base, extension, true, + loader); + if (parent != null) { + bundle.setParent(parent); + } + } + loaderCache.put(bundleName, bundle); + return bundle; + } + + if (extension != null) { + ResourceBundle fallback = handleGetXMLBundle(base, extension, loadBase, loader); + if (fallback != null) { + loaderCache.put(bundleName, fallback); + return fallback; + } + } + loaderCache.put(bundleName, loadBase ? MISSINGBASE : MISSING); + return null; + } + + private void setLocale(String name) { + String language = "", country = "", variant = ""; + if (name.length() > 1) { + int nextIndex = name.indexOf('_', 1); + if (nextIndex == -1) { + nextIndex = name.length(); + } + language = name.substring(1, nextIndex); + if (nextIndex + 1 < name.length()) { + int index = nextIndex; + nextIndex = name.indexOf('_', nextIndex + 1); + if (nextIndex == -1) { + nextIndex = name.length(); + } + country = name.substring(index + 1, nextIndex); + if (nextIndex + 1 < name.length()) { + variant = name.substring(nextIndex + 1, name.length()); + } + } + } + this.locale = new Locale(language, country, variant); + } + + private static String strip(String name) { + int index = name.lastIndexOf('_'); + if (index != -1) { + return name.substring(0, index); + } + return null; + } + + private Enumeration getLocalKeys() { + return (Enumeration)resources.propertyNames(); + } + + /** {@inheritDoc} */ + public Locale getLocale() { + return this.locale; + } + + /** {@inheritDoc} */ + public Enumeration getKeys() { + if (parent == null) { + return getLocalKeys(); + } + return new Enumeration() { + private Enumeration local = getLocalKeys(); + private Enumeration pEnum = parent.getKeys(); + + private Object nextElement; + + private boolean findNext() { + if (nextElement != null) { + return true; + } + while (pEnum.hasMoreElements()) { + Object next = pEnum.nextElement(); + if (!resources.containsKey(next)) { + nextElement = next; + return true; + } + } + return false; + } + + public boolean hasMoreElements() { + if (local.hasMoreElements()) { + return true; + } + return findNext(); + } + + public Object nextElement() { + if (local.hasMoreElements()) { + return local.nextElement(); + } + if (findNext()) { + Object result = nextElement; + nextElement = null; + return result; + } + // Cause an exception + return pEnum.nextElement(); + } + }; + } + + /** {@inheritDoc} */ + protected Object handleGetObject(String key) { + if (key == null) { + throw new NullPointerException("key must not be null"); + } + return resources.get(key); + } + + /** {@inheritDoc} */ + public String toString() { + return "XMLResourceBundle: " + getLocale(); + } + + private class CatalogueHandler extends DefaultHandler { + + private static final String CATALOGUE = "catalogue"; + private static final String MESSAGE = "message"; + + private StringBuffer valueBuffer = new StringBuffer(); + private Stack elementStack = new Stack(); + private String currentKey = null; + + private boolean isOwnNamespace(String uri) { + return ("".equals(uri)); + } + + private QName getParentElementName() { + return (QName)elementStack.peek(); + } + + /** {@inheritDoc} */ + public void startElement(String uri, String localName, String qName, + Attributes atts) throws SAXException { + super.startElement(uri, localName, qName, atts); + QName elementName = new QName(uri, qName); + if (isOwnNamespace(uri)) { + if (CATALOGUE.equals(localName)) { + //nop + } else if (MESSAGE.equals(localName)) { + if (!CATALOGUE.equals(getParentElementName().getLocalName())) { + throw new SAXException(MESSAGE + " must be a child of " + CATALOGUE); + } + this.currentKey = atts.getValue("key"); + } else { + throw new SAXException("Invalid element name: " + elementName); + } + } else { + //ignore + } + this.valueBuffer.setLength(0); + elementStack.push(elementName); + } + + /** {@inheritDoc} */ + public void endElement(String uri, String localName, String qName) throws SAXException { + super.endElement(uri, localName, qName); + elementStack.pop(); + if (isOwnNamespace(uri)) { + if (CATALOGUE.equals(localName)) { + //nop + } else if (MESSAGE.equals(localName)) { + if (this.currentKey == null) { + throw new SAXException( + "current key is null (attribute 'key' might be mistyped)"); + } + resources.put(this.currentKey, this.valueBuffer.toString()); + this.currentKey = null; + } + } else { + //ignore + } + this.valueBuffer.setLength(0); + } + + /** {@inheritDoc} */ + public void characters(char[] ch, int start, int length) throws SAXException { + super.characters(ch, start, length); + valueBuffer.append(ch, start, length); + } + + } + +} |