biz.c24.io.spring.config.C24ModelBeanDefinitionParser.java Source code

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Here is the source code for biz.c24.io.spring.config.C24ModelBeanDefinitionParser.java

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/*
 * Copyright 2011 the 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 biz.c24.io.spring.config;

import static biz.c24.io.spring.config.BeanDefinitionUtils.*;

import java.io.IOException;
import java.util.Set;
import java.util.regex.Pattern;

import org.springframework.beans.factory.BeanDefinitionStoreException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
import org.springframework.beans.factory.xml.BeanDefinitionParser;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.core.type.filter.AssignableTypeFilter;
import org.springframework.core.type.filter.RegexPatternTypeFilter;
import org.springframework.core.type.filter.TypeFilter;
import org.springframework.util.StringUtils;
import org.w3c.dom.Element;

import biz.c24.io.spring.core.C24Model;

/**
 * {@link BeanDefinitionParser} to build a {@link C24Model} bean definition.
 * 
 * @author Oliver Gierke
 */
public class C24ModelBeanDefinitionParser extends AbstractBeanDefinitionParser {

    public static final String DEFAULT_BEAN_NAME = "_c24model";

    /*
     * (non-Javadoc)
     * @see org.springframework.beans.factory.xml.BeanDefinitionParser#parse(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
     */
    @Override
    public AbstractBeanDefinition parseInternal(Element element, ParserContext context) {

        String basePackage = element.getAttribute("base-package");
        String baseElement = element.getAttribute("base-element");

        if (StringUtils.hasText(baseElement) && StringUtils.hasText(basePackage)) {
            throw new BeanDefinitionStoreException("Either base-package or base-element are allowed!");
        }

        Object source = context.extractSource(element);
        AbstractBeanDefinition modelDefinition = StringUtils.hasText(baseElement)
                ? getC24ModelFromElement(baseElement, context, source)
                : getC24ModelFromPackage(basePackage, context, source);

        BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(C24Model.class);
        builder.addConstructorArgValue(modelDefinition);

        return getSourcedBeanDefinition(builder, context.extractSource(element));
    }

    /**
     * Classpath scans the given base package for subclasses of {@link biz.c24.io.api.data.Element} whose names end on
     * {@code DocumentRootElement}.
     * 
     * @param basePackage
     * @param context
     * @param source
     * @return
     */
    private AbstractBeanDefinition getC24ModelFromPackage(String basePackage, ParserContext context,
            Object source) {

        ClassPathScanningCandidateComponentProvider provider = new ClassPathScanningCandidateComponentProvider(
                false);
        provider.addIncludeFilter(new TypeFilter() {

            private final TypeFilter nameFilter = new RegexPatternTypeFilter(
                    Pattern.compile(".*DocumentRootElement"));
            private final TypeFilter typeFilter = new AssignableTypeFilter(biz.c24.io.api.data.Element.class);

            public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
                    throws IOException {
                return nameFilter.match(metadataReader, metadataReaderFactory)
                        && typeFilter.match(metadataReader, metadataReaderFactory);
            }
        });

        Set<BeanDefinition> result = provider.findCandidateComponents(basePackage);
        if (result.size() != 1) {
            context.getReaderContext().error("Found none or multiple classes ending on 'DocumentRootElement'!",
                    source);
        }

        String elementClassName = result.iterator().next().getBeanClassName();
        return getC24ModelFromElement(elementClassName, context, source);
    }

    /**
     * Creates an {@link AbstractBeanDefinition} for an {@link biz.c24.io.api.data.Element}.
     * 
     * @param baseElement
     * @param context
     * @param source
     * @return
     */
    private AbstractBeanDefinition getC24ModelFromElement(String baseElement, ParserContext context,
            Object source) {

        BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(baseElement);
        builder.setFactoryMethod("getInstance");
        return getSourcedBeanDefinition(builder, source);
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#resolveId(org.w3c.dom.Element, org.springframework.beans.factory.support.AbstractBeanDefinition, org.springframework.beans.factory.xml.ParserContext)
     */
    @Override
    protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)
            throws BeanDefinitionStoreException {

        String resolvedId = super.resolveId(element, definition, parserContext);
        return StringUtils.hasText(resolvedId) ? resolvedId : DEFAULT_BEAN_NAME;
    }
}