import java.lang.*; import java.util.*; import java.sql.*; 
public class cn1 { 
 public static void main(String args[])  {      String   s="顾强";      String   s1="ab";      String   drv=null;      Connection conn=null;             Statement  stmt=null;             ResultSet  rs=null;             int       rowcount=0; 
     Properties p = new Properties(); 
   try   {         //注册数据库驱动程序为Oracle驱动     Class.forName("oracle.jdbc.driver.OracleDriver");    }    catch (java.lang.ClassNotFoundException e)    {            //这样写是为了方便调试程序,出错打印mydb()就知道在什么地方出错了      System.err.println("mydb(): " + e.getMessage());    } 
   try    {           conn = DriverManager.getConnection(          "jdbc:oracle:thin:@127.0.0.1:1521:orc8i", "java", "88888888");       }       catch (SQLException ex)       {              System.err.println("conn:"+ex.getMessage());   } 
         if (conn!=null)              System.out.println("connection successful");          else              System.out.println("connection failure"); 
          try           {              stmt=conn.createStatement(); 
       }        catch (SQLException ex)        {                System.err.println("createStatement();"+ex.getMessage()); 
  } 
   try    {        rs=stmt.executeQuery("select *  from userdata"); 
   }    catch (SQLException ex)    {        System.err.println("stmt.excuteQuery();"+ex.getMessage()); 
   } 
   try    {        while (rs.next())        { 
                  System.out.println("username: "+ rs.getString(1));                   System.out.println("password: "+rs.getString(2));                   System.out.println("email: " +rs.getString(3)); 
       } 
       }        catch (SQLException ex)        {                System.err.println("A ERROR is failure" +ex.getMessage()); 
   } 
   //test1();   p=System.getProperties(); 
  //p.list(System.out);   drv=p.getProperty("java.class.path");   //System.out.println("driver="+drv); 
  
 } 
  public static  void test1()  {      cn2      cn2obj = new cn2();   printClassName(cn2obj);  } 
 public static void printClassName(Object obj)  {             System.out.println("The class of " + obj +                                " is " + obj.getClass().getName());   } 
 } 
class cn2 { 
    public void test()     {       System.out.println("11111111111"); 
    } 
    public String toString()     {        return "1111";     } 
}  
 
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