jsp新代码第229课

new229.java

package pack03;

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

public class new229
{
  private static String driver = "com.mysql.jdbc.Driver";
  private static String url = "jdbc:mysql://locahost:3306/test?useUnicode=true&characterEncoding=utf-8";
  private static String user = "root";
  private static String pwd = "mysql123";
  private static Connection conn = null;
  
  public static Connection getConnection()
  {
    if(conn == null)
    {
      try
      {
        Class.forName(driver);
        conn = DriverManager.getConnection(url,user,pwd);
        
      } 
      catch (Exception e)
      {
        e.printStackTrace();
      }
    }
    
    return conn;

  }
  
  public static void close(ResultSet rs)
  {
    if (rs != null)
    {
      try
      {
        rs.close();
      } catch (SQLException e)
      {
        e.printStackTrace();
      }
    }
  }
  
  public static void close(PreparedStatement pstmt)
  {
    if(pstmt != null)
    {
      try
      {
        pstmt.close();
      } 
      catch (SQLException e)
      {
        e.printStackTrace();
      }
    }
  }
  
  public static void close(Connection conn)
  {
    if (conn != null)
    {
      try
      {
        conn.close();
      } catch (SQLException e)
      {
        e.printStackTrace();
      }
    }
  }
}