condb.java

网上选课程序：a.使用JSP/Servlet开发

//package educatenet;
package wsxk;
import java.sql.*;
public class ConDB
{

  /////////////
  String url="jdbc:mysql://localhost/wsxk?useUnicode=true&characterEncoding=gb2312";
  //pubs为你的数据库的
  //String user="";
  //String password="";
  String sDBDriver = "com.mysql.jdbc.Driver";
  Connection conn = null;
  ResultSet rs = null;

  public ConDB()
  {
      try {
        Class.forName(sDBDriver).newInstance();
      }
      catch (ClassNotFoundException ex) {
 System.out.println("4444");     }
      catch (IllegalAccessException ex) {
  System.out.println("2222");      }
      catch (InstantiationException ex) {
   System.out.println("3333");     }

  }

  public ResultSet executeQuery(String sql)
  {
    try {
      rs = null;
      Connection conn= DriverManager.getConnection(url);
      Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
      rs = stmt.executeQuery(sql);
    }
    catch (SQLException ex) {
 System.out.println("执行错误");     }
    return rs;
  }


        public void executeUpdate(String strSQL)
        {
                try
                {
                        Connection conn= DriverManager.getConnection(url);
                        Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
                        stmt.executeQuery(strSQL);
                }
                catch(SQLException ex)
                {
                        System.err.println("连接数据库失败了，异常为：" +ex.getMessage());
                }
        }

         public String ex_chinese(String str)
         {
                 if(str==null)
                 {
                                str  ="" ;
                 }
                 else
                 {
                           try
                           {
                                         str = new String(str.getBytes("iso-8859-1"),"gb2312") ;
                           }
                           catch (Exception ex)
                           {
                                        System.err.println("异常为：" +ex.getMessage());
                           }
                 }
                 return str ;
         }

         public String gettime()
         {
                String datestr =  "" ;
                try
                {
                        java.text.DateFormat df = new java.text.SimpleDateFormat("yyyy年MM月dd日 HH点ss分") ;
                        java.util.Date date = new java.util.Date() ;
                        datestr = df.format(new java.util.Date()) ;
                }
                catch (Exception ex)
                {
                        System.err.println("异常为：" +ex.getMessage());
                }

                return datestr ;
         }
}