lens-examples/src/main/java/org/apache/lens/examples/DatabaseUtil.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.lens.examples;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

/**
 * The Class DatabaseUtil.
 */
public final class DatabaseUtil {

  private DatabaseUtil() {

  }

  /**
   * Initalize database storage.
   *
   * @throws Exception the exception
   */
  public static void initializeDatabaseStorage() throws Exception {
    try {
      Class.forName("org.hsqldb.jdbcDriver");
    } catch (ClassNotFoundException e) {
      System.err.println("Unable to locate the JDBC driver class for DB Storage");
    }
    Connection con = DriverManager.getConnection("jdbc:hsqldb:/tmp/db-storage.db", "SA", "");

    con.setAutoCommit(true);
    Statement statement = con.createStatement();
    BufferedReader reader = null;
    try {
      InputStream file = DatabaseUtil.class.getClassLoader().getResourceAsStream("db-storage-schema.sql");
      reader = new BufferedReader(new InputStreamReader(file, "UTF-8"));
      String line;
      while ((line = reader.readLine()) != null) {
        if (line.trim().equals("") || line.startsWith("--")) {
          continue;
        }
        statement.executeUpdate(line);
      }
    } finally {
      if (reader != null) {
        reader.close();
      }
      statement.execute("SHUTDOWN");
      statement.close();
      con.close();
    }
  }

  /**
   * The main method.
   *
   * @param args the arguments
   * @throws Exception the exception
   */
  public static void main(String[] args) throws Exception {
    DatabaseUtil.initializeDatabaseStorage();
  }
}