hsqldblistener.java

使用jsp开发的一个基于HSQLDB的快餐订购管理系统

package com.uiwz.db;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hsqldb.Server;

/**  
 * 控制数据库的周期.  
 * context启动的时候，启动hsqldb数据库服务器，context关闭时shutdown数据库服务器  
 *  
 * @author Lingo  
 * @version 1.0  
 * @since 2007-03-13  
 * @see javax.servlet.ServletContextListener  
 * @web.listener  
 */  
public class HsqldbListener implements ServletContextListener {
	
	private static final Log log = LogFactory.getLog(HsqldbListener.class);
	
	/**  
	 * 等待数据库停止的最大时间.  
	 */  
	public static final int WAIT_TIME = 1000;

	/**  
	 * 处理context初始化事件.  
	 * @param sce ServletContextEvent  
	 */  
	public void contextInitialized(ServletContextEvent sce) {
		try {
			Properties prop = new Properties();
			prop.load(getClass().getResourceAsStream("/hsqldb.properties"));
			String username = prop.getProperty("hsql.username");
			String password = prop.getProperty("hsql.password");

			String databaseName = prop.getProperty("hsql.dbname");
			int port = Integer.parseInt(prop.getProperty("hsql.port"));
			String hsqlPath = prop.getProperty("hsql.path");
			
			String databasePath = sce.getServletContext().getRealPath(hsqlPath) + "/" + databaseName;
			//System.out.println(sce.getServletContext().getRealPath(hsqlPath));
			
			Server server = new Server();
			server.setDatabaseName(0, databaseName);
			server.setDatabasePath(0, databasePath);
			server.setPort(port);
			server.setSilent(true);
			server.start();
			log.info("Started HSQLDB server on port:" + port);
		} catch (Exception e) {
			log.error(e);
			e.printStackTrace();
		}
	}

	/**  
	 * 处理context销毁事件.  
	 * @param sce ServletContextEvent  
	 */  
	public void contextDestroyed(ServletContextEvent sce) {

		Connection conn = null;
		Statement state = null;

		try {
			// 向数据库发送shutdown命令，关闭数据库
			log.info("Stoping HSQLDB server...");
			conn = Database.getConnection();
			state = conn.createStatement();
			state.executeUpdate("SHUTDOWN;");
			Thread.sleep(WAIT_TIME);
			log.info("Stoped HSQLDB server");
		} catch (Exception e) {
			log.error(e);
		} finally {
			// 确保关闭Statement
			if (state != null) {
				try {
					state.close();
					state = null;
				} catch (SQLException e) {
					log.error(e);
				}
			}

			// 确保关闭Connection
			if (conn != null) {
				try {
					conn.close();
					conn = null;
				} catch (SQLException e) {
					log.error(e);
				}
			}
		}
	}
}