com.javacreed.secureproperties.utils.DbHelper.java Source code

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Here is the source code for com.javacreed.secureproperties.utils.DbHelper.java

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/*
 * #%L
 * JavaCreed Secure Properties Encoder
 * %%
 * Copyright (C) 2012 - 2015 Java Creed
 * %%
 * 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.
 * #L%
 */
package com.javacreed.secureproperties.utils;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Objects;

import javax.sql.DataSource;

import org.apache.commons.dbcp2.BasicDataSource;

/**
 * @author Albert Attard
 */
public class DbHelper {

    /**
     *
     * @param closeable
     */
    public static void closeQuietly(final AutoCloseable closeable) {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (final Exception e) {
            }
        }
    }

    /**
     *
     * @return
     * @throws SQLException
     */
    public static DbHelper create() throws SQLException {
        final BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("org.h2.Driver");
        dataSource.setUrl("jdbc:h2:./target/test");
        dataSource.setUsername("sa");
        dataSource.setPassword("");

        final DbHelper helper = new DbHelper(dataSource);
        return helper;
    }

    /** */
    private final BasicDataSource dataSource;

    /**
     *
     * @param dataSource
     * @throws NullPointerException
     */
    public DbHelper(final BasicDataSource dataSource) throws NullPointerException {
        this.dataSource = Objects.requireNonNull(dataSource);
    }

    /**
     *
     */
    public void close() {
        DbHelper.closeQuietly(dataSource);
    }

    // public Statement createStatement() throws SQLException {
    // return connection.createStatement();
    // }

    /**
     *
     * @param query
     * @throws SQLException
     */
    public void execute(final String query) throws SQLException {
        try (Connection connection = getConnection(); Statement statement = connection.createStatement()) {
            statement.execute(query);
        }
    }

    /**
     *
     * @return
     * @throws SQLException
     */
    public Connection getConnection() throws SQLException {
        return dataSource.getConnection();
    }

    /**
     *
     * @return
     */
    public DataSource getDataSource() {
        return dataSource;
    }

    /**
     *
     * @param query
     * @return
     * @throws SQLException
     */
    public String queryForSingleValue(final String query) throws SQLException {
        try (Connection connection = getConnection();
                Statement statement = connection.createStatement();
                ResultSet resultSet = statement.executeQuery(query);) {
            if (resultSet.next()) {
                final String value = resultSet.getString(1);

                if (resultSet.next()) {
                    throw new SQLException("More than one row was returned");
                }

                return value;
            }
        }

        throw new SQLException("No rows were returned");
    }
}