java适当的输入输出

Question

你好，我一直在想实现一个函数的正确方法，这个函数有以下功能

1程序启动时，显示文本以输入键或将字段留空

2如果输入了文本，则执行A

3如果未输入文本，则执行B

这就是我到目前为止所做的

System.out.println("Enter any key to get data or leave empty");
//Just give some value
int value = 0;
try {
    for (int i = 5; i > 0; i--) {
        System.out.println("Starting in " + i);
        Thread.sleep(1000);
        //If enter was pressed then theoretically value
        //should be 1(Not working)
        value = System.in.read();
    }
    if (value != 0) {
        Database.getInstance().getAllStamps();
    } else {
        start();
    }

} catch (Exception e) {
    e.printStackTrace();
}

Answer 1

  Scanner sc = new Scanner(System.in);
  for (int i = 5; i > 0; i ) {
     System.out.println("Starting in " + i); 
     Thread.sleep(1000);     // Execution pauses
     if(sc.hasNext())
          // call your function
          break;
     }
 }

或者

boolean flag = false;
for (int i = 5; i > 0; i ) {
     System.out.println("Starting in " + i); 
     Thread.sleep(1000);     // Execution pauses
     if(sc.hasNext())
         flag = true;

     }
 }
 if(flag) { 
 // call your function 

 }

Answer 2

获取原始输入的一种方法是使用^{}

用这样的方式：

Scanner sc = new Scanner(System.in);
if(sc.hasNext()){
    //do stuff with input
}
else{
    //handle stuff
}