org.openeos.hibernate.internal.configurators.BundleModelClassConfigurator.java Source code

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Here is the source code for org.openeos.hibernate.internal.configurators.BundleModelClassConfigurator.java

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/**
 * Copyright 2014 Fernando Rincon Martin <frm.rincon@gmail.com>
 *
 * 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.openeos.hibernate.internal.configurators;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashSet;
import java.util.Set;

import javassist.util.proxy.MethodFilter;
import javassist.util.proxy.MethodHandler;
import javassist.util.proxy.ProxyFactory;

import org.hibernate.cfg.Configuration;
import org.hibernate.usertype.UserType;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.openeos.dao.ListType;
import org.openeos.hibernate.internal.ConfigurationProvider;

public class BundleModelClassConfigurator implements Configurator {

    private static final Logger LOG = LoggerFactory.getLogger(BundleModelClassConfigurator.class);

    private static final String MODEL_CLASS_HEADER = "Uno-Model-Classes";

    private BundleContext context;
    private Set<Class<?>> listTypeProxyCreatedSet = new HashSet<Class<?>>();

    public BundleModelClassConfigurator(BundleContext context) {
        this.context = context;
    }

    @Override
    public void init(ConfigurationProvider configurationProvider) {
        LOG.debug("Initializing configuration of model class bundles");
        Configuration conf = configurationProvider.getConfiguration();
        registerModelBundles(conf);
        configurationProvider.invalidate();
    }

    private void registerModelBundles(Configuration conf) {
        for (Bundle bundle : context.getBundles()) {
            LOG.trace(String.format("Checking if bundle '%s' has model classes", bundle.getSymbolicName()));
            if (hasModel(bundle) && (bundle.getState() & (Bundle.INSTALLED | Bundle.ACTIVE | Bundle.RESOLVED
                    | Bundle.STARTING | Bundle.STOPPING)) != 0) {
                registerBundle(conf, bundle);
            }
        }
    }

    private void registerBundle(Configuration conf, Bundle bundle) {
        String header = bundle.getHeaders().get(MODEL_CLASS_HEADER);
        for (String clazz : header.split(",")) {
            try {
                LOG.debug(String.format("Trying to register model class '%s'", clazz.trim()));
                Class<?> classToRegister = bundle.loadClass(clazz.trim());
                conf.addAnnotatedClass(classToRegister);
                checkForListType(conf, classToRegister);
            } catch (ClassNotFoundException ex) {
                LOG.error(String.format(
                        "Class not found exception when trying to register model class '%s' for bundle '%s'", clazz,
                        bundle.getSymbolicName()), ex);
            }
        }
    }

    private void checkForListType(Configuration conf, Class<?> persistentClass) {
        try {
            BeanInfo beanInfo = Introspector.getBeanInfo(persistentClass);
            PropertyDescriptor[] props = beanInfo.getPropertyDescriptors();
            for (int i = 0; i < props.length; i++) {
                PropertyDescriptor prop = props[i];
                if (ListType.class.isAssignableFrom(prop.getPropertyType())) {
                    checkForCreateListTypeType(conf, prop.getPropertyType());
                }
            }
        } catch (Exception e) {
            LOG.error(String.format("An exception occured when trying to get bean info of class %s",
                    persistentClass.toString()), e);
        }
    }

    private void checkForCreateListTypeType(Configuration conf, final Class<?> propertyType)
            throws NoSuchMethodException, IllegalArgumentException, InstantiationException, IllegalAccessException,
            InvocationTargetException {
        if (!listTypeProxyCreatedSet.contains(propertyType)) {
            ProxyFactory factory = new ProxyFactory();
            factory.setSuperclass(ListTypeUserType.class);
            factory.setFilter(new MethodFilter() {

                @Override
                public boolean isHandled(Method method) {
                    return Modifier.isAbstract(method.getModifiers());
                }
            });
            MethodHandler handler = new MethodHandler() {

                @Override
                public Object invoke(Object self, Method thisMethod, Method proceed, Object[] args)
                        throws Throwable {
                    if (thisMethod.getName().equals("returnedClass") && args.length == 0) {
                        LOG.debug("Handling method returnedClass() of type ListTypeUserType", thisMethod);
                        return propertyType;
                    } else {
                        throw new UnsupportedOperationException();
                    }
                }

            };
            Object type = factory.create(new Class<?>[0], new Object[0], handler);
            conf.registerTypeOverride((UserType) type,
                    new String[] { propertyType.getSimpleName(), propertyType.getName() });
            listTypeProxyCreatedSet.add(propertyType);
        }
    }

    private boolean hasModel(Bundle bundle) {
        return bundle.getHeaders().get(MODEL_CLASS_HEADER) != null;
    }

}