org.springframework.batch.item.data.Neo4jItemWriter.java Source code

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Here is the source code for org.springframework.batch.item.data.Neo4jItemWriter.java

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/*
 * Copyright 2012 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 org.springframework.batch.item.data;

import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.neo4j.ogm.session.Session;
import org.neo4j.ogm.session.SessionFactory;

import org.springframework.batch.item.ItemWriter;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.data.neo4j.template.Neo4jOperations;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;

/**
 * <p>
 * A {@link ItemWriter} implementation that writes to a Neo4j database.
 * </p>
 *
 * <p>
 * This writer is thread-safe once all properties are set (normal singleton
 * behavior) so it can be used in multiple concurrent transactions.
 * </p>
 *
 * @author Michael Minella
 *
 */
public class Neo4jItemWriter<T> implements ItemWriter<T>, InitializingBean {

    protected static final Log logger = LogFactory.getLog(Neo4jItemWriter.class);

    private boolean delete = false;

    private Neo4jOperations template;

    private SessionFactory sessionFactory;

    private boolean useSession = false;

    public void setDelete(boolean delete) {
        this.delete = delete;
    }

    /**
     * Set the {@link Neo4jOperations} to be used to save items
     *
     * @param template the template implementation to be used
     * @deprecated Use {@link #setSessionFactory(SessionFactory)}
     */
    @Deprecated
    public void setTemplate(Neo4jOperations template) {
        this.template = template;
    }

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    /**
     * Checks mandatory properties
     *
     * @see InitializingBean#afterPropertiesSet()
     */
    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.state(template != null || this.sessionFactory != null,
                "A Neo4JOperations implementation or a SessionFactory is required");

        this.useSession = this.sessionFactory != null;
    }

    /**
     * Write all items to the data store.
     *
     * @see org.springframework.batch.item.ItemWriter#write(java.util.List)
     */
    @Override
    public void write(List<? extends T> items) throws Exception {
        if (!CollectionUtils.isEmpty(items)) {
            doWrite(items);
        }
    }

    /**
     * Performs the actual write using the template.  This can be overriden by
     * a subclass if necessary.
     *
     * @param items the list of items to be persisted.
     */
    protected void doWrite(List<? extends T> items) {
        if (delete) {
            delete(items);
        } else {
            save(items);
        }
    }

    private void delete(List<? extends T> items) {
        if (this.useSession) {
            Session session = this.sessionFactory.openSession();

            items.forEach(session::delete);
        } else {
            for (T item : items) {
                this.template.delete(item);
            }
        }
    }

    private void save(List<? extends T> items) {
        if (this.useSession) {
            Session session = this.sessionFactory.openSession();

            items.forEach(session::save);
        } else {
            for (T item : items) {
                this.template.save(item);
            }
        }
    }
}