java异常处理的简单练习

class Teacher
{
  private Computer cmp;
  public void shangKe()throws NoPlanException      /*声明异常*/
  {
    cmp=new Computer();
    try
    {
      cmp.run();
    }
    catch(LanPingException e)               /*电脑捕获处理蓝屏的异常*/                   
    {
      cmp.recst();
    }
    catch(MaoYanException e)                /*电脑捕获处理电脑冒烟的异常*/
    {
      throw new NoPlanException("上课无法继续,因为"+e.getMessage());    /*电脑无法处理这个异常，继续把这个异常抛给老师来处理*/   
    }
    
    System.out.println("老师上课");                /*没有异常，老师就正常上课*/
  }
}
class LanPingException extends Exception               /*自定义蓝屏异常*/
{
  LanPingException(String m)
  {
    super(m);
  }
}

class MaoYanException extends Exception             /*自定义电脑冒烟异常*/
{
  MaoYanException(String m)
  {
    super(m);
  }
}
class NoPlanException extends Exception             /*自定义老师处理异常*/
{
  NoPlanException(String m)
  {
    super(m);
  }
}

class Computer
{
  private int state=3;           /*不同的异常状态选择*/
  
  public void run()throws LanPingException,MaoYanException
  {
    if(state==2)                     
    {
      throw new LanPingException("电脑蓝屏了");        /*符合条件就抛出异常对象*/
    }
    if(state==3)
    {
      throw new MaoYanException("电脑冒烟了");
    }
    System.out.println("电脑运行");
  }
  
  
  public void recst()
  {
    System.out.println("电脑重启");
  }
}

class ExceptionText
{
  public static void main(String args[])
  {
    Teacher t=new Teacher();
    try
    {
      t.shangKe();
    }
    catch(NoPlanException e)               /*老师捕获处理电脑冒烟异常*/   
    {
      System.out.println(e.toString());
    }    
  }
}