Simple exercises for java exception handling

class Teacher
{
  private Computer cmp;
  public void shangKe()throws NoPlanException      /*Declare exception*/
  {
    cmp=new Computer();
    try
    {
      ();
    }
    catch(LanPingException e)               /*Computer captures exceptions to handle blue screen*/                   
    {
      ();
    }
    catch(MaoYanException e)                /*Computer captures and handles computer smoking exception*/
    {
      throw new NoPlanException("The class cannot continue because"+());    /*The computer cannot handle this exception, continue to throw this exception to the teacher to handle*/   
    }
    
    ("Teacher teaches");                /*There is no abnormality, the teacher will attend class normally*/
  }
}
class LanPingException extends Exception               /*Custom blue screen exception*/
{
  LanPingException(String m)
  {
    super(m);
  }
}

class MaoYanException extends Exception             /*Custom computer smoke abnormality*/
{
  MaoYanException(String m)
  {
    super(m);
  }
}
class NoPlanException extends Exception             /*Custom teacher handles exceptions*/
{
  NoPlanException(String m)
  {
    super(m);
  }
}

class Computer
{
  private int state=3;           /* Different exception status selection*/
  
  public void run()throws LanPingException,MaoYanException
  {
    if(state==2)                     
    {
      throw new LanPingException("The computer is blue");        /*Exception object is thrown if the conditions are met*/
    }
    if(state==3)
    {
      throw new MaoYanException("The computer is smoking");
    }
    ("Computer running");
  }
  
  
  public void recst()
  {
    ("Computer Restart");
  }
}

class ExceptionText
{
  public static void main(String args[])
  {
    Teacher t=new Teacher();
    try
    {
      ();
    }
    catch(NoPlanException e)               /*The teacher catches and handles computer smoking abnormality*/   
    {
      (());
    }    
  }
}