System的exit

源码

 /**
     * Terminates the currently running Java Virtual Machine. The
     * argument serves as a status code; by convention, a nonzero status
     * code indicates abnormal termination.
     * 

* This method calls the exit method in class * Runtime. This method never returns normally. *

* The call System.exit(n) is effectively equivalent to * the call: *

     * Runtime.getRuntime().exit(n)
     * 

功 能: 关闭所有文件，终止正在执行的进程。

exit（0）：正常运行程序并退出程序；

exit（1）：非正常运行导致退出程序；

测试方法：

 // 测试方法
    public static void main(String[] args) {

        StackType stackType = new StackType();
        try {
            DATA3 data3 = stackType.PopST(stackType); // 此处调用了 exit 直接关闭了当前现成 之后方法都未执行
        }catch (Exception ee){
            System.out.printf("sss");
        }


    }


    DATA3 PopST(StackType s){
        if(s.top==0){
            System.out.printf("栈为空！");
            System.exit(0);
            System.out.printf("关闭后"); //永远不会执行
        }
        return (s.data[s.top--]);
    }

控制台输出

Connected to the target VM, address: '127.0.0.1:52564', transport: 'socket'
Disconnected from the target VM, address: '127.0.0.1:52564', transport: 'socket'
栈为空！
Process finished with exit code 0