com.romeikat.datamessie.core.base.util.execute.ExecuteWithTransactionAndResult.java Source code

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Here is the source code for com.romeikat.datamessie.core.base.util.execute.ExecuteWithTransactionAndResult.java

Source

package com.romeikat.datamessie.core.base.util.execute;

/*-
 * ============================LICENSE_START============================
 * data.messie (core)
 * =====================================================================
 * Copyright (C) 2013 - 2017 Dr. Raphael Romeikat
 * =====================================================================
 * This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public
License along with this program.  If not, see
<http://www.gnu.org/licenses/gpl-3.0.html>.
 * =============================LICENSE_END=============================
 */

import org.hibernate.StatelessSession;
import org.hibernate.Transaction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class ExecuteWithTransactionAndResult<T> {

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

    private final StatelessSession statelessSession;

    public ExecuteWithTransactionAndResult(final StatelessSession statelessSession) {
        this.statelessSession = statelessSession;
    }

    public T execute() {
        Transaction tx = null;
        try {
            tx = beginTransaction(statelessSession);
            final T result = executeWithResult(statelessSession);
            commitTransaction(tx);
            return result;
        } catch (final Exception e) {
            onException(e);
            try {
                rollbackTransaction(tx);
            } catch (final Exception e2) {
                onException(e2);
            }
            statelessSession.close();
            return null;
        }
    }

    protected abstract T executeWithResult(StatelessSession statelessSession);

    protected void onException(final Exception e) {
        LOG.error("Could not execute transaction", e);
    }

    private Transaction beginTransaction(final StatelessSession statelessSession) {
        return statelessSession.beginTransaction();
    }

    private void commitTransaction(final Transaction tx) {
        if (tx == null) {
            return;
        }

        tx.commit();
    }

    private void rollbackTransaction(final Transaction tx) {
        if (tx == null) {
            return;
        }

        tx.rollback();
    }

}