connectmanager.java

一个专家资料的管理系统

package cn.com.likai.mms.db;

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

import org.eclipse.jface.preference.IPreferenceStore;

import cn.com.likai.mms.Activator;
import cn.com.likai.mms.preferences.DBPreferencePage;

public class ConnectManager {
	private static Connection con;
	private static String className,url,username,password;
	private ConnectManager(){}
	
	public static Connection getConnection() throws SQLException{
		if(con != null && !con.isClosed())
			return con;//不为空且没关闭
		IPreferenceStore ps = Activator.getDefault().getPreferenceStore();
		className = ps.getString(DBPreferencePage.CLASSNAME_KEY);
		url = ps.getString(DBPreferencePage.URL_KEY);
		username = ps.getString(DBPreferencePage.USERNAME_KEY);
		password = ps.getString(DBPreferencePage.PASSWORD_KEY);
		//生成一个数据库连接
		try{
			Class.forName(className);
			con = DriverManager.getConnection(url,username,password);
		}catch(ClassNotFoundException e){e.printStackTrace();}
		return con;
	}
	//提供一个真正关闭Connection的方法
	public static void closeConnection(){
		if(con == null) return;
		try{con.close();}catch(SQLException e){e.printStackTrace();}
	}

}