applicationlistener.java

又一个课程设计 简易 JSP 论坛 功能较简单的那种, 界面上模仿了 Discuz JSP 本来就学的不行, 只是尽量实现了 MVC

package cn.ialvin.bbs.listener;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.SQLException;
import java.util.regex.Matcher;

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

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;

import cn.ialvin.bbs.dao.DAOFactory;
import cn.ialvin.sql.ConnectionPool;
import cn.ialvin.sql.DBConfig;
import cn.ialvin.util.MatcheProcesser;
import cn.ialvin.util.RegExp;

public class ApplicationListener implements ServletContextListener, MatcheProcesser {
	public void contextDestroyed(ServletContextEvent e) {
		if (ApplicationListener.pool != null) {
			ApplicationListener.pool.close();
		}
	}
	ServletContext application = null;
	private static ConnectionPool pool = null;
	private boolean initDBConfig() {
		String config_xml_path = this.application.getRealPath("/WEB-INF/coxn.xml");
		File file = new File(config_xml_path);
		if (!file.exists() && !file.isFile())
			return false;
		if (!file.canRead())
			return false;
		SAXBuilder sb = new SAXBuilder();
		Document doc = null;
		try {
			doc = sb.build(new FileInputStream(file));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (JDOMException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		if (doc == null) {
			return false;
		}
		Element root = doc.getRootElement();
		DBConfig config = new DBConfig();
		config.setDBType(root.getChild("DBType").getText());
		config.setDriver(root.getChild("driver").getText());
		config.setUID(root.getChild("uid").getText());
		config.setPWD(root.getChild("pwd").getText());
		config.setMax(Integer.parseInt(root.getChild("max").getText()));
		config.setMin(Integer.parseInt(root.getChild("min").getText()));
		config.setUrl(root.getChild("dburl").getText().trim());
		config.setUrl(
			new RegExp("\\<\\[([^\\]]+)\\]\\>", "g")
				.replace(config.getUrl(), this)
		);
		try {
			ConnectionPool pool = ConnectionPool.newInstance(config);
			DAOFactory factory = new DAOFactory(pool);
			boolean flag = factory.testDBType();
			factory.destroy();
			if (!flag) return false;
			this.application.setAttribute("DBPool", pool);
			ApplicationListener.pool = pool;
		} catch (SQLException e) {
			e.printStackTrace();
			return false;
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
			return false;
		}
		return true;
	}

	public String doProcess(Matcher m) {
		return application.getRealPath(m.group(1));
	}

	public void contextInitialized(ServletContextEvent e) {
		this.application = e.getServletContext();
		try {
			if (this.initDBConfig())
				this.application.setAttribute("DB_CONNECTION_INITED", "YES");
		} catch(Exception ex) {
			ex.printStackTrace();
		}
	}

}