Java XML QName getXmlRootElementQName(Class clazz)

Description

get Xml Root Element Q Name

License

Apache License

Parameter

Parameter	Description
clazz	a parameter

Return

namespace of root element qname or null if this is not object does not represent a root element

Declaration

public static QName getXmlRootElementQName(Class<?> clazz) 

Method Source Code

//package com.java2s;
/*//w  w w  .  ja v  a2s.  c o  m
 * 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.
 */

import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;

import java.security.AccessController;
import java.security.PrivilegedAction;

import java.util.StringTokenizer;

import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlSchema;
import javax.xml.namespace.QName;

public class Main {
    /**
     * @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);
    }

    /**
     * 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);
            }
        });
    }

    /**
     * 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;
    }
}

Related

1. getTypeQName(Class type)
2. getUniquePOAName(QName serviceName, String portName, String poaName)
3. getValueAsQName(XMLStreamReader reader, String value)
4. getXmlElementRefOrElementQName(Class jaxbClass, Field field)
5. getXmlQName(final NamespaceContext context, final String value)
6. getXMLValue(String xml, String xQuery, QName resultType)
7. getXSTypeAsString(QName qname)
8. hasAnnotatedQname(Object obj)
9. hasChildElement(QName qName, Element element)