java - Eclipse 中的 java.util.Scanner 无限循环

Question

我必须从控制台读取这种输入:

word1
word2

word3
word4

我已经尝试过了:

public static void lectSC(Scanner sc, String l, boolean next) {
        l=sc.nextLine();     //keep the first line
        while(!l.isEmpty()){ //if it is not empty go! until the white line
            checkDicc(l);//check if is the word that I am looking for
            l=sc.nextLine(); //get the next word
        }
        l=sc.nextLine(); //take the nextLine which has a word3
        while(!l.isEmpty()){
            parejas.add(l);
            next=sc.hasNext(); //HERE IT IS THE INFINITY LOOP
            if(next){ //I try with this next know which is the value of hasNext(), but I never arrive here when it is the last line.
                l=sc.nextLine();
            }else{
                l=""; //It is how it should exit
            }
        }
        System.out.println("OUT");
    }

我不得不说，当我从键盘上单击 Ctrl-Z 时，程序会继续，但它不能那样工作。

谢谢!!

Answer 1

The hasNext() method is getting blocked for input

，当从控制台读取时，程序需要一个流，并且它将等待进一步的输入。

下面是该方法的官方 java 文档，它确实提到了它的阻塞性质，但没有太多细节:- http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#hasNext()