uk.ac.ed.inf.ace.utils.PreparedStatements.java Source code

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Here is the source code for uk.ac.ed.inf.ace.utils.PreparedStatements.java

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/*
 * Copyright 2012 Daniel Renshaw <d.renshaw@sms.ed.ac.uk>.
 *
 * 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 uk.ac.ed.inf.ace.utils;

import com.google.common.base.Supplier;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import uk.ac.ed.inf.ace.Database;

/**
 * @author "Daniel Renshaw" <d.renshaw@sms.ed.ac.uk>
 */
public class PreparedStatements extends InstrumentedCache<Supplier<String>, PreparedStatement> {

    private static final Logger LOGGER = Logger.getLogger(PreparedStatements.class.getName());

    public PreparedStatements(final Database database) {
        super("PreparedStatements", CacheBuilder.newBuilder()
                .removalListener(new RemovalListener<Supplier<String>, PreparedStatement>() {
                    @Override
                    public void onRemoval(RemovalNotification<Supplier<String>, PreparedStatement> notification) {
                        try {
                            notification.getValue().close();
                        } catch (SQLException exception) {
                            LOGGER.log(Level.SEVERE, "Failed to close a prepared statement.", exception);
                        }
                    }
                }).concurrencyLevel(1).build(new CacheLoader<Supplier<String>, PreparedStatement>() {
                    @Override
                    public PreparedStatement load(Supplier<String> sqlSupplier) throws Exception {
                        database.open();
                        return database.prepareStatement(sqlSupplier.get());
                    }
                }));
    }

    @Override
    public PreparedStatement get(Supplier<String> query) throws Exception {
        return super.get(query);
    }

    @Override
    public PreparedStatement getUnchecked(Supplier<String> query) {
        return super.getUnchecked(query);
    }
}