db.java

JSP做的 登陆查找添加页面适合初学者模仿练习小的应用程序！

/**
 * 
 */
package Bean;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

/**
 * @author ng
 *
 */
public class Db {
	/**
	 * 
	 * 建立数据库连接
	 */
	
	String sDbDriver="";
	String sUrl="";
	String sUser="";
	String sPassword="";
	Connection con=null;
	ResultSet rs=null;
	Statement stmt=null;
	public Db() throws Exception
	{
		Properties p=new Properties();
		InputStream is=getClass().getResourceAsStream("db.properties");
		p.load(is);
		sDbDriver=p.getProperty("DbDriver",sDbDriver);
		sUser=p.getProperty("User",sUser);
		sUrl=p.getProperty("Url",sUrl);
		sPassword=p.getProperty("Password",sPassword);
		Class.forName(sDbDriver);	
	}
	public Connection getconnection()
	{
		try
		{  		
			con=DriverManager.getConnection(sUrl,sUser,sPassword);
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
		
		return con;
	}
	/**
	 * 
	 * @param sql
	 * @return 建立数据连接，执行SQL语句，返回结果集
	 * @throws Exception
	 */
	public  ResultSet executeQuery(String sql) throws Exception
	{
		con=getconnection();
		stmt=con.createStatement();
		System.out.println(sql);
		rs=stmt.executeQuery(sql);
		return rs;
	}
	/**
	 * 
	 * @param sql
	 * @throws Exception
	 * 执行对数据库增删改之类的sql语句
	 */
	public int executeUpdate(String sql) throws Exception
	{
		con=getconnection();
		stmt=con.createStatement();
		int i=stmt.executeUpdate(sql);
		stmt.close();
		con.close();
		return i;
		
	}
	public void close() throws Exception
	{
		rs.close();
		stmt.close();
		con.close();		
	}
	
	
	
}