public class Test3 {

public static void main(String[] agrs) {

Calculator cal = new Calculator();

double r = 0.0;

try {

r = cal.divide(10, 0);

} catch (Exception e) {

System.out.println(e.getMessage());

}finally {

System.out.println("任何情况下都会走到这个分支！！！");

if(cal.isSwichOn()) {

cal.close();

}

}

}

}

class Calculator {

private boolean isSwichOn = false;

public boolean isSwichOn() {

return isSwichOn;

}

public void setSwichOn(boolean swichOn) {

this.isSwichOn = isSwichOn;

}

public void open() {

isSwichOn = true;

System.out.println("打开计算器电源，不过记得用完要关掉哦！！！");

}

public double divide(int a, int b) throws Exception {

double result = 0d;

open();

if (b!=0) {

result = a / b;

} else {

throw new Exception("严重警告：不能被0除！！！");

}

System.out.println(result);

close();

return result;

}

public void close() {

System.out.println("用完关掉电源，不然会爆！！！");

isSwichOn = false;

}

}