Java tutorial
/* * 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.axis2.jaxws.utility; import org.apache.axis2.java.security.AccessController; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.xml.bind.JAXBElement; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlEnumValue; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.bind.annotation.XmlSchema; import javax.xml.bind.annotation.XmlType; import javax.xml.bind.annotation.XmlElementRef; import javax.xml.namespace.QName; 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.PrivilegedAction; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.StringTokenizer; /** * */ public class XMLRootElementUtil { private static final Log log = LogFactory.getLog(XMLRootElementUtil.class); /** 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 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; } /** * @param clazz * @return namespace of @XmlType or null if this is object does not represent a root element */ public static QName getXmlTypeQName(Class clazz) { // See if the object has an @XmlType XmlType t = (XmlType) getAnnotation(clazz, XmlType.class); if (t == null) { return null; } String name = t.name(); String namespace = t.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); } /** * 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 static Map<String, PropertyDescriptorPlus> createPropertyDescriptorMap(Class jaxbClass) throws NoSuchFieldException, IntrospectionException { if (log.isDebugEnabled()) { log.debug("Get the PropertyDescriptor[] for " + jaxbClass); } PropertyDescriptor[] pds = Introspector.getBeanInfo(jaxbClass).getPropertyDescriptors(); Map<String, PropertyDescriptorPlus> map = new HashMap<String, PropertyDescriptorPlus>(); // 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; if (log.isDebugEnabled()) { log.debug(" Start: Find xmlname for property:" + pd.getName()); } 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; if (log.isDebugEnabled()) { log.debug(" Found field " + field.getName() + " which has xmlname=" + xmlName); } if (map.get(xmlName) != null) { if (log.isDebugEnabled()) { log.debug(" ALERT: property " + map.get(xmlName).getPropertyName() + " already has this same xmlName..this may cause problems."); } } map.put(xmlName.getLocalPart(), new PropertyDescriptorPlus(pd, xmlName)); 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; if (log.isDebugEnabled()) { log.debug(" Found field " + field.getName() + " which has xmlname=" + xmlName); } if (map.get(xmlName) != null) { if (log.isDebugEnabled()) { log.debug(" ALERT: property " + map.get(xmlName).getPropertyName() + " already has this same xmlName..this may cause problems."); } } map.put(xmlName.getLocalPart(), new PropertyDescriptorPlus(pd, xmlName)); break; } } } // We didn't find a field. Default the xmlname to the property name if (!found) { String xmlName = pd.getName(); if (log.isDebugEnabled()) { log.debug(" A matching field was not found. Defaulting xmlname to " + xmlName); } if (map.get(xmlName) != null) { if (log.isDebugEnabled()) { log.debug(" ALERT: property " + map.get(xmlName).getPropertyName() + " already has this same xmlName..this may cause problems."); } } map.put(xmlName, new PropertyDescriptorPlus(pd, xmlName)); } if (log.isDebugEnabled()) { log.debug(" End: Find xmlname for property:" + pd.getName()); } } 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; fields = (List<Field>) AccessController.doPrivileged(new PrivilegedAction() { public Object 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 Annotation getAnnotation(final AnnotatedElement element, final Class annotation) { return (Annotation) AccessController.doPrivileged(new PrivilegedAction() { public Object run() { return element.getAnnotation(annotation); } }); } }