org.directwebremoting.spring.namespace.NamespaceParserHelper Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of dwr Show documentation

DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boiler plate code between the web browser and your Java code.

The newest version!

/*
 * Copyright 2010 original author or authors
 *
 * 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.
 */
package org.directwebremoting.spring.namespace;

import java.lang.reflect.Method;

import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.HierarchicalBeanFactory;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.util.StringUtils;

/**
 * Convenience methods to find things in context while parsing DWR namespace.
 *
 * @author Jose Noheda [[email protected]]
 */
public abstract class NamespaceParserHelper
{
    /**
     *  Tries to obtain the beanClassName from the definition and if that fails tries to get it from
     *  the parent (and even parent BeanFactory if we have to).
     *
     *  @param definition a non null instance
     *  @param registry a non null instance
     *  @return class name or null if not found
     */
    protected String resolveBeanClassname(BeanDefinition definition, BeanDefinitionRegistry registry)
    {
        String beanClassName = definition.getBeanClassName();
        while(!StringUtils.hasText(beanClassName))
        {
            try
            {
                Method m = definition.getClass().getMethod("getParentName", new Class[0]);
                String parentName = (String) m.invoke(definition, new Object[0]);
                BeanDefinition parentDefinition = findParentDefinition(parentName, registry);
                beanClassName = parentDefinition.getBeanClassName();
                definition = parentDefinition;
            } catch (Exception e)
            {
                throw new FatalBeanException("No parent bean could be found for " + definition, e);
            }
        }
        return beanClassName;
    }

    /**
     * Finds a parent bean definition in the hierarchy of contexts.
     *
     * @param parentName any
     * @param registry any
     * @return any
     */
    protected BeanDefinition findParentDefinition(String parentName, BeanDefinitionRegistry registry)
    {
        if (registry != null)
        {
            if (registry.containsBeanDefinition(parentName))
            {
                return registry.getBeanDefinition(parentName);
            }
            else if (registry instanceof HierarchicalBeanFactory)
            {
                // Try to get parent definition from the parent BeanFactory. This could return null
                BeanFactory parentBeanFactory = ((HierarchicalBeanFactory) registry).getParentBeanFactory();
                return findParentDefinition(parentName, (BeanDefinitionRegistry) parentBeanFactory);
            }
        }
        return null;
    }

}