com.threewks.thundr.jpa.JpaModule.java Source code

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Here is the source code for com.threewks.thundr.jpa.JpaModule.java

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/*
 * This file is a component of thundr, a software library from 3wks.
 * Read more: http://www.3wks.com.au/thundr
 * Copyright (C) 2013 3wks, <thundr@3wks.com.au>
 *
 * 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 com.threewks.thundr.jpa;

import java.util.LinkedHashMap;
import java.util.Map;

import javax.servlet.ServletContext;

import org.apache.commons.lang3.StringUtils;

import com.threewks.thundr.action.method.ActionInterceptorRegistry;
import com.threewks.thundr.configuration.Environment;
import com.threewks.thundr.injection.InjectionContext;
import com.threewks.thundr.injection.Module;
import com.threewks.thundr.injection.UpdatableInjectionContext;
import com.threewks.thundr.jpa.exception.JpaException;
import com.threewks.thundr.jpa.intercept.JpaSession;
import com.threewks.thundr.jpa.intercept.JpaSessionActionInterceptor;
import com.threewks.thundr.logger.Logger;
import com.threewks.thundr.module.DependencyRegistry;

public class JpaModule implements Module {
    public static final String PersistenceManagerRegistry = String.format("thundr-jpa-%s",
            PersistenceManagerRegistryImpl.class);
    public static final String PersistenceManagersConfigName = "persistenceManagers";

    @Override
    public void requires(DependencyRegistry dependencyRegistry) {

    }

    @Override
    public void initialise(UpdatableInjectionContext injectionContext) {

    }

    @Override
    public void configure(UpdatableInjectionContext injectionContext) {
        PersistenceManagerRegistry registry = initializePersistenceManagerRegistry(injectionContext);
        registerActionInterceptorAnnotations(injectionContext, registry);
    }

    @Override
    public void start(UpdatableInjectionContext injectionContext) {

    }

    @Override
    public void stop(InjectionContext injectionContext) {
        PersistenceManagerRegistry registry = injectionContext.get(PersistenceManagerRegistry.class);
        registry.clear();
    }

    protected final void registerActionInterceptorAnnotations(UpdatableInjectionContext injectionContext,
            PersistenceManagerRegistry persistenceManagerRegistry) {
        ActionInterceptorRegistry actionInterceptorRegistry = injectionContext.get(ActionInterceptorRegistry.class);
        actionInterceptorRegistry.registerInterceptor(JpaSession.class,
                new JpaSessionActionInterceptor(persistenceManagerRegistry));
    }

    protected final PersistenceManagerRegistry initializePersistenceManagerRegistry(
            UpdatableInjectionContext injectionContext) {
        PersistenceManagerRegistry registry = new PersistenceManagerRegistryImpl();
        injectionContext.inject(registry).as(PersistenceManagerRegistry.class);

        for (Map.Entry<String, String> persistenceManagerAndUnit : getPersistenceUnitNames(injectionContext)
                .entrySet()) {
            String persistenceManagerName = persistenceManagerAndUnit.getKey();
            String persistenceUnitName = persistenceManagerAndUnit.getValue();
            PersistenceManager persistenceManager = new PersistenceManagerImpl(persistenceUnitName);
            registry.register(persistenceManagerName, persistenceManager);
            injectionContext.inject(persistenceManager).named(persistenceManagerName).as(PersistenceManager.class);
            Logger.info("Registered persistence manager %s against persistence unit %s", persistenceManagerName,
                    persistenceUnitName);
        }

        // Put reference into servlet context to provide context listener with access to call
        // PersistenceManagerRegister#clear() on shutdown.
        ServletContext context = injectionContext.get(ServletContext.class);
        context.setAttribute(PersistenceManagerRegistry, registry);

        return registry;
    }

    /**
     * Gets a list of persistence unit names to initialize. Defaults to a single persistence unit named after the
     * current environment as provided by {@link Environment#get()}. Override this if you wish to initialize a
     * different or multiple persistence managers.
     * 
     * @param injectionContext
     * 
     * @return a list of persistence unit names
     */
    protected Map<String, String> getPersistenceUnitNames(UpdatableInjectionContext injectionContext) {
        Map<String, String> persistenceManagerAndPersistenceUnit = new LinkedHashMap<String, String>();

        String persistenceManagersString = injectionContext.get(String.class, PersistenceManagersConfigName);
        String[] persistenceManagers = StringUtils.split(persistenceManagersString);
        if (persistenceManagers == null) {
            persistenceManagerAndPersistenceUnit.put(PersistenceManager.DefaultName,
                    PersistenceManager.DefaultName);
        } else {
            for (String persistenceManager : persistenceManagers) {
                String[] persistenceManagerAndUnit = StringUtils.split(persistenceManager, ":");
                if (persistenceManagerAndUnit.length != 2) {
                    throw new JpaException(
                            "Failed to initialise persistence managers, each persistence manager is expected to be paired with a persistence unit in the form <manager:unit>, but got '%s'",
                            persistenceManager);
                }
                persistenceManagerAndPersistenceUnit.put(persistenceManagerAndUnit[0],
                        persistenceManagerAndUnit[1]);
            }
        }
        return persistenceManagerAndPersistenceUnit;
    }
}