dbconnection.java

这是一个JSP的网上书店

package db;
import java.sql.*;

public class DBConnection{
	String dbDriver="sun.jdbc.odbc.JdbcOdbcDriver";
	String connectionStr="jdbc:odbc:userDB";
	Connection conn=null;
	Statement stmt=null;
	ResultSet rs=null;
	
	public DBConnection(){}
	
    public void getConnection()
    {
		try{
			Class.forName(dbDriver);
			conn=DriverManager.getConnection(connectionStr,"","");
		}
		catch(SQLException e)
		{
			e.printStackTrace();
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
	}
	
	public void setDbDriver(String driver)
	{
		this.dbDriver=driver;
	}
	
	public void setConnectionStr(String url)
	{
		this.connectionStr=url;
	}
	
	public ResultSet query(String sql)
	{
		try{
			stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
			                          ResultSet.CONCUR_READ_ONLY);
			rs=stmt.executeQuery(sql);
		}catch(SQLException e)
		{
			e.printStackTrace();
		}
		return rs;
	}
	
	public int update(String sql)
	{
		int i=0;
		try{
			stmt = conn.createStatement();
			i= stmt.executeUpdate(sql);
		}catch(SQLException e)
		{
			e.printStackTrace();
		}
		return i;
		
	}
	
	public void close()
	{
		try{
			if(rs!=null)  rs.close();
			if(stmt!=null) stmt.close();
			if(conn!=null) conn.close();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}