hsqldblistener.java

来自「anewssystem新闻发布系统集成使用了spring hibernate f」· Java 代码 · 共 150 行

package anni.core.web.listener;

import java.io.IOException;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

import java.util.Properties;

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

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 {
    /**
     * 配置文件中的占位符，代表webapp发布后的根目录.
     */
    public static final String TOKEN = "${webapp.root}";

    /**
     * 等待数据库停止的最大时间.
     */
    public static final int WAIT_TIME = 1000;

    /**
     * jdbc的url.
     */
    private String url;

    /**
     * 登陆用户名.
     */
    private String username;

    /**
     * 登陆密码.
     */
    private String password;

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

            String databaseName = prop.getProperty("hsql.databaseName");
            int port = Integer.parseInt(prop.getProperty("hsql.port"));
            String hsqlPath = prop.getProperty("hsql.path");

            // FIXME: 因为要用到getRealPath方法获得路径，在使用war包发布的时候会出现问题
            if (hsqlPath.startsWith(TOKEN)) {
                String webappRoot = sce.getServletContext().getRealPath("/");
                hsqlPath = hsqlPath.substring(TOKEN.length());
                //if(hsqlPath.charAt(0) == '/' || hsqlPath.charAt(0) == '\\')
                //{
                //  hsqlPath = hsqlPath.substring(1);
                //}
                hsqlPath = webappRoot + hsqlPath;
            }

            String databasePath = hsqlPath + "/" + databaseName;
            url = "jdbc:hsqldb:hsql://localhost:" + port + "/"
                + databaseName;

            Server server = new Server();
            server.setDatabaseName(0, databaseName);

            // ServletContext sc = sce.getServletContext();
            server.setDatabasePath(0, databasePath);
            server.setPort(port);
            server.setSilent(true);
            server.start();
            Thread.sleep(WAIT_TIME);
        } catch (IOException ex) {
            System.out.println(
                "HsqldbListener : contextInitialized : error : " + ex);
        } catch (InterruptedException ex) {
            System.out.println(
                "HsqldbListener : contextInitialized : error : " + ex);
        }
    }

    /**
     * 处理context销毁事件.
     * @param sce ServletContextEvent
     */
    public void contextDestroyed(ServletContextEvent sce) {
        try {
            Class.forName("org.hsqldb.jdbcDriver");

            Connection conn = null;
            Statement state = null;

            try {
                // 向数据库发送shutdown命令，关闭数据库
                conn = DriverManager.getConnection(url, username, password);
                state = conn.createStatement();
                state.executeUpdate("SHUTDOWN;");
            } catch (SQLException ex1) {
                System.err.println("关闭数据库时出现异常：" + ex1);
            } finally {
                // 确保关闭Statement
                if (state != null) {
                    try {
                        state.close();
                        state = null;
                    } catch (SQLException ex1) {
                        System.err.println(ex1);
                    }
                }

                // 确保关闭Connection
                if (conn != null) {
                    try {
                        conn.close();
                        conn = null;
                    } catch (SQLException ex1) {
                        System.err.println(ex1);
                    }
                }
            }
        } catch (ClassNotFoundException ex) {
            System.err.println(
                "HsqldbListener : contextDestoryed : error : " + ex);

            // ex.printStackTrace();
        }
    }
}