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-rw-r--r-- | sca-java-2.x/branches/2.0-Beta1/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/XMLRootElementUtil.java | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/sca-java-2.x/branches/2.0-Beta1/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/XMLRootElementUtil.java b/sca-java-2.x/branches/2.0-Beta1/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/XMLRootElementUtil.java new file mode 100644 index 0000000000..d177d53eda --- /dev/null +++ b/sca-java-2.x/branches/2.0-Beta1/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/XMLRootElementUtil.java @@ -0,0 +1,299 @@ +/* + * 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. + */ + +package org.apache.tuscany.sca.databinding.jaxb; + +import java.beans.IntrospectionException; +import java.beans.Introspector; +import java.beans.PropertyDescriptor; +import java.lang.annotation.Annotation; +import java.lang.reflect.AnnotatedElement; +import java.lang.reflect.Field; +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.StringTokenizer; +import java.util.WeakHashMap; + +import javax.xml.bind.JAXBElement; +import javax.xml.bind.annotation.XmlElement; +import javax.xml.bind.annotation.XmlElementRef; +import javax.xml.bind.annotation.XmlEnumValue; +import javax.xml.bind.annotation.XmlRootElement; +import javax.xml.bind.annotation.XmlSchema; +import javax.xml.namespace.QName; + +/** + * + */ +public class XMLRootElementUtil { + + /** + * TUSCANY-3167 + * Cache for property descriptors + */ + private static Map<Class<?>, Map<String, JAXBPropertyDescriptor>> PROPERTY_MAP = + new WeakHashMap<Class<?>, Map<String, JAXBPropertyDescriptor>>(); + + /** Constructor is intentionally private. This class only provides static utility methods */ + private XMLRootElementUtil() { + + } + + /** + * @param clazz + * @return namespace of root element qname or null if this is not object does not represent a + * root element + */ + public static QName getXmlRootElementQNameFromObject(Object obj) { + + // A JAXBElement stores its name + if (obj instanceof JAXBElement) { + return ((JAXBElement<?>)obj).getName(); + } + + Class<?> clazz = (obj instanceof java.lang.Class) ? (Class<?>)obj : obj.getClass(); + return getXmlRootElementQName(clazz); + } + + /** + * @param clazz + * @return namespace of root element qname or null if this is not object does not represent a + * root element + */ + public static QName getXmlRootElementQName(Class<?> clazz) { + + // See if the object represents a root element + XmlRootElement root = (XmlRootElement)getAnnotation(clazz, XmlRootElement.class); + if (root == null) { + return null; + } + + String name = root.name(); + String namespace = root.namespace(); + + // The name may need to be defaulted + if (name == null || name.length() == 0 || name.equals("##default")) { + name = getSimpleName(clazz.getCanonicalName()); + } + + // The namespace may need to be defaulted + if (namespace == null || namespace.length() == 0 || namespace.equals("##default")) { + Package pkg = clazz.getPackage(); + XmlSchema schema = (XmlSchema)getAnnotation(pkg, XmlSchema.class); + if (schema != null) { + namespace = schema.namespace(); + } else { + namespace = ""; + } + } + + return new QName(namespace, name); + } + + /** + * @param clazz + * @return namespace of root element qname or null if this is not object does not represent a root element + */ + public static String getEnumValue(Enum<?> myEnum) { + Field f; + String value; + try { + f = myEnum.getClass().getField(myEnum.name()); + + f.setAccessible(true); + + XmlEnumValue xev = (XmlEnumValue)getAnnotation(f, XmlEnumValue.class); + if (xev == null) { + value = f.getName(); + } else { + value = xev.value(); + } + } catch (SecurityException e) { + value = null; + } catch (NoSuchFieldException e) { + value = null; + } + + return value; + } + + /** + * utility method to get the last token in a "."-delimited package+classname string + * + * @return + */ + private static String getSimpleName(String in) { + if (in == null || in.length() == 0) { + return in; + } + String out = null; + StringTokenizer tokenizer = new StringTokenizer(in, "."); + if (tokenizer.countTokens() == 0) + out = in; + else { + while (tokenizer.hasMoreTokens()) { + out = tokenizer.nextToken(); + } + } + return out; + } + + /** + * The JAXBClass has a set of bean properties each represented by a PropertyDescriptor Each of + * the fields of the class has an associated xml name. The method returns a map where the key is + * the xml name and value is the PropertyDescriptor + * + * @param jaxbClass + * @return map + */ + public synchronized static Map<String, JAXBPropertyDescriptor> createPropertyDescriptorMap(Class<?> jaxbClass) + throws NoSuchFieldException, IntrospectionException { + + Map<String, JAXBPropertyDescriptor> map = PROPERTY_MAP.get(jaxbClass); + if (map != null) { + return map; + } + + map = new HashMap<String, JAXBPropertyDescriptor>(); + PropertyDescriptor[] pds = Introspector.getBeanInfo(jaxbClass).getPropertyDescriptors(); + + // Unfortunately the element names are stored on the fields. + // Get all of the fields in the class and super classes + + List<Field> fields = getFields(jaxbClass); + + // Now match up the fields with the property descriptors...Sigh why didn't JAXB put the @XMLElement annotations on the + // property methods! + for (PropertyDescriptor pd : pds) { + + // Skip over the class property..it is never represented as an xml element + if (pd.getName().equals("class")) { + continue; + } + + // For the current property, find a matching field...so that we can get the xml name + boolean found = false; + + int index = 0; + for (Field field : fields) { + String fieldName = field.getName(); + + // Use the name of the field and property to find the match + if (fieldName.equalsIgnoreCase(pd.getDisplayName()) || fieldName.equalsIgnoreCase(pd.getName())) { + // Get the xmlElement name for this field + QName xmlName = getXmlElementRefOrElementQName(field.getDeclaringClass(), field); + found = true; + map.put(xmlName.getLocalPart(), new JAXBPropertyDescriptor(pd, xmlName, index)); + index++; + break; + } + + // Unfortunately, sometimes the field name is preceeded by an underscore + if (fieldName.startsWith("_")) { + fieldName = fieldName.substring(1); + if (fieldName.equalsIgnoreCase(pd.getDisplayName()) || fieldName.equalsIgnoreCase(pd.getName())) { + // Get the xmlElement name for this field + QName xmlName = getXmlElementRefOrElementQName(field.getDeclaringClass(), field); + found = true; + + map.put(xmlName.getLocalPart(), new JAXBPropertyDescriptor(pd, xmlName, index)); + index++; + break; + } + } + } + + // We didn't find a field. Default the xmlname to the property name + if (!found) { + String xmlName = pd.getName(); + + map.put(xmlName, new JAXBPropertyDescriptor(pd, xmlName, index)); + index++; + } + } + PROPERTY_MAP.put(jaxbClass, map); + return map; + } + + /** + * Gets all of the fields in this class and the super classes + * + * @param beanClass + * @return + */ + static private List<Field> getFields(final Class<?> beanClass) { + // This class must remain private due to Java 2 Security concerns + List<Field> fields = AccessController.doPrivileged(new PrivilegedAction<List<Field>>() { + public List<Field> run() { + List<Field> fields = new ArrayList<Field>(); + Class<?> cls = beanClass; + while (cls != null) { + Field[] fieldArray = cls.getDeclaredFields(); + for (Field field : fieldArray) { + fields.add(field); + } + cls = cls.getSuperclass(); + } + return fields; + } + }); + + return fields; + } + + /** + * Get the name of the field by looking at the XmlElement annotation. + * + * @param jaxbClass + * @param fieldName + * @return + * @throws NoSuchFieldException + */ + private static QName getXmlElementRefOrElementQName(Class<?> jaxbClass, Field field) throws NoSuchFieldException { + XmlElementRef xmlElementRef = (XmlElementRef)getAnnotation(field, XmlElementRef.class); + if (xmlElementRef != null) { + return new QName(xmlElementRef.namespace(), xmlElementRef.name()); + } + XmlElement xmlElement = (XmlElement)getAnnotation(field, XmlElement.class); + + // If XmlElement does not exist, default to using the field name + if (xmlElement == null || xmlElement.name().equals("##default")) { + return new QName("", field.getName()); + } + return new QName(xmlElement.namespace(), xmlElement.name()); + } + + /** + * Get an annotation. This is wrappered to avoid a Java2Security violation. + * @param cls Class that contains annotation + * @param annotation Class of requrested Annotation + * @return annotation or null + */ + private static <T extends Annotation> T getAnnotation(final AnnotatedElement element, final Class<T> annotation) { + return AccessController.doPrivileged(new PrivilegedAction<T>() { + public T run() { + return element.getAnnotation(annotation); + } + }); + } +} |