com.masetta.spann.orm.hibernate.support.HibernateSupport.java Source code

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Here is the source code for com.masetta.spann.orm.hibernate.support.HibernateSupport.java

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/**
 * Copyright 2010 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 com.masetta.spann.orm.hibernate.support;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import javax.persistence.EntityManager;

import org.hibernate.Filter;
import org.hibernate.Session;

import com.masetta.spann.spring.util.Factory;

public class HibernateSupport {

    public static <T> T doWithFilters(EntityManager entityManager, Collection<FilterActivation> filters,
            Factory<T> callback) {

        if (filters == null || filters.isEmpty()) {
            return callback.create();
        }

        Session session = (Session) entityManager.getDelegate();
        List<String> list = enableFilters(session, filters);
        try {
            return callback.create();
        } finally {
            disableFilters(session, list);
        }
    }

    private static void disableFilters(Session session, List<String> filters) {
        for (String filter : filters) {
            session.disableFilter(filter);
        }
    }

    private static List<String> enableFilters(Session session, Collection<FilterActivation> filterList) {

        if (filterList == null || filterList.isEmpty())
            return Collections.emptyList();

        List<String> applied = new ArrayList<String>();
        Filter filter;
        for (FilterActivation f : filterList) {
            String filterName = f.getName();

            Collection<Map.Entry<String, Object>> parameters = f.getParameters();
            // skip filters which are already enabled,
            filter = session.getEnabledFilter(filterName);
            if (filter != null) {
                if (f.getParameters().size() > 0) {
                    throw new IllegalArgumentException("Filter '" + f.getName()
                            + "' is already activated. Can not enable filter with different arguments.");
                }
                continue;
            }

            filter = session.enableFilter(filterName);
            applied.add(filterName);
            for (Map.Entry<String, Object> e : parameters) {
                Object value = e.getValue();
                if (value == null) {
                    filter.setParameter(e.getKey(), value);
                } else if (value instanceof Collection) {
                    filter.setParameterList(e.getKey(), (Collection) value);
                } else if (value.getClass().isArray()) {
                    filter.setParameterList(e.getKey(), (Object[]) value);
                } else {
                    filter.setParameter(e.getKey(), value);
                }
            }
            filter.validate();
        }
        return applied;
    }

}