vaadin-framework/src/com/itmill/toolkit/demo/util/SampleCalendarDatabase.java

package com.itmill.toolkit.demo.util;

import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Timestamp;

/**
 * Creates temporary database named toolkit with sample table named employee and
 * populates it with data. By default we use HSQLDB. Ensure that you have
 * hsqldb.jar under WEB-INF/lib directory. Database is will be created into
 * memory.
 * 
 * @author IT Mill Ltd.
 * 
 */
public class SampleCalendarDatabase {

	public static final int ENTRYCOUNT = 100;

	public static final String DB_TABLE_NAME = "calendar";
	public static final String PROPERTY_ID_START = "EVENTSTART";
	public static final String PROPERTY_ID_END = "EVENTEND";
	public static final String PROPERTY_ID_TITLE = "TITLE";
	public static final String PROPERTY_ID_NOTIME = "NOTIME";

	private Connection connection = null;

	private static final String[] titles = new String[] { "Meeting", "Dentist",
			"Haircut", "Bank", "Birthday", "Library", "Rent", "Acme test",
			"Party" };

	/**
	 * Create temporary database.
	 * 
	 */
	public SampleCalendarDatabase() {
		// connect to SQL database
		connect();

		// initialize SQL database
		createTables();

		// test by executing sample JDBC query
		testDatabase();
	}

	/**
	 * Creates sample table named employee and populates it with data.Use the
	 * specified database connection.
	 * 
	 * @param connection
	 */
	public SampleCalendarDatabase(Connection connection) {
		// initialize SQL database
		createTables();

		// test by executing sample JDBC query
		testDatabase();
	}

	/**
	 * Connect to SQL database. In this sample we use HSQLDB and an toolkit
	 * named database in implicitly created into system memory.
	 * 
	 */
	private void connect() {
		// use memory-Only Database
		String url = "jdbc:hsqldb:mem:toolkit";
		try {
			Class.forName("org.hsqldb.jdbcDriver").newInstance();
			connection = DriverManager.getConnection(url, "sa", "");
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * use for SQL commands CREATE, DROP, INSERT and UPDATE
	 * 
	 * @param expression
	 * @throws SQLException
	 */
	public void update(String expression) throws SQLException {
		Statement st = null;
		st = connection.createStatement();
		int i = st.executeUpdate(expression);
		if (i == -1) {
			System.out.println("SampleDatabase error : " + expression);
		}
		st.close();
	}

	/**
	 * Create test table and few rows. Issue note: using capitalized column
	 * names as HSQLDB returns column names in capitalized form with this demo.
	 * 
	 */
	private void createTables() {
		try {
			String stmt = null;
			stmt = "CREATE TABLE "
					+ DB_TABLE_NAME
					+ " ( ID INTEGER IDENTITY, TITLE VARCHAR(100), "
					+ "EVENTSTART DATETIME, EVENTEND DATETIME, NOTIME BOOLEAN  )";
			update(stmt);
			for (int j = 0; j < ENTRYCOUNT; j++) {
				Timestamp start = new Timestamp(new java.util.Date().getTime());
				start.setDate((int) ((Math.random() - 0.4) * 200));
				start.setMinutes(0);
				start.setHours(8 + (int) Math.random() * 12);
				Timestamp end = new Timestamp(start.getTime());
				if (Math.random() < 0.7) {
					long t = end.getTime();
					long hour = 60 * 60 * 1000;
					t = t + hour
							+ (long) (Math.round(Math.random() * 3 * hour));
					end.setTime(t);
				}

				stmt = "INSERT INTO "
						+ DB_TABLE_NAME
						+ "(TITLE, EVENTSTART, EVENTEND, NOTIME) VALUES ("
						+ "'"
						+ titles[(int) (Math.round(Math.random()
								* (titles.length - 1)))] + "','" + start
						+ "','" + end + "'," + (Math.random() > 0.7) + ")";
				update(stmt);
			}
		} catch (SQLException e) {
			if (e.toString().indexOf("Table already exists") == -1)
				throw new RuntimeException(e);
		}
	}

	/**
	 * Test database connection with simple SELECT command.
	 * 
	 */
	private String testDatabase() {
		String result = null;
		try {
			Statement stmt = connection.createStatement(
					ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.CONCUR_UPDATABLE);
			ResultSet rs = stmt.executeQuery("SELECT COUNT(*) FROM "
					+ DB_TABLE_NAME);
			rs.next();
			result = "rowcount for table test is " + rs.getObject(1).toString();
			stmt.close();
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
		return result;
	}

	public Connection getConnection() {
		return connection;
	}

}