java基础—继承连接

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/*
老师用电脑上课。

问题领域中涉及两个对象。
毕老师，电脑。

分析其中的问题。

比如电脑蓝屏。冒烟啦。

class LanPingException extends Exception
{
LanPingException(String msg)
{
super(msg);
}
}

class MaoYanException extends Exception
{
MaoYanException(String msg)
{
super(msg);
}
}

class NoPlanException extends Exception
{
NoPlanException(String msg)
{
super(msg);
}
}

class Computer
{
private int state = 2;
public void run()throws LanPingException,MaoYanException
{
  if(state==1)
   throw new LanPingException("电脑蓝屏啦！！");
  if(state==2)
   throw new MaoYanException("电脑冒烟啦！！");

  System.out.println("电脑运行");
}
public void reset()
{
  state = 0;
  System.out.println("电脑重启");
}
}

class Teacher
{
private String name;
private Computer comp;
Teacher(String name)
{
  this.name = name;
  comp = new Computer();
}

public void prelect()throws NoPlanException
{
  try
  {
   comp.run();
   System.out.println(name+"讲课");

  }
  catch (LanPingException e)
  {
   System.out.println(e.toString());
   comp.reset();
   prelect();
  }
  catch (MaoYanException e)
  {
   System.out.println(e.toString());
   test();
   //可以对电脑进行维修。
//   throw e;
   throw new NoPlanException("课时进度无法完成，原因："+e.getMessage());
  }

}
public void test()
{
  System.out.println("大家练习");
}
}
class ExceptionTest
{
public static void main(String[] args)
{
  Teacher t = new Teacher("毕老师");
  try
  {
   t.prelect();

  }
  catch (NoPlanException e)
  {
   System.out.println(e.toString()+"......");
   System.out.println("换人");

}
}
}

class NoAddException extends Exception
{}

void addData(Data d)throws NoAddException
{

连接数据库
try
{
添加数据。出现异常 SQLException();
}
catch(SQLException e)
{
//处理代码。

throw new NoAddException();
}
fianlly
{
关闭数据库。
}
}

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