相关疑难解决方法(0)

scanner.close()有什么作用?

说我有以下示例代码:

Scanner scan1 = new Scanner(System.in);    // declaring new Scanner called scan1
int x = scan1.nextInt();    // scan for user input and set it to x
System.out.println(x);    // print the value of x
scan1.close();    // closes the scanner (I don't know exactly what this does)
Scanner scan2 = new Scanner(System.in); // declaring new Scanner called scan1
int y = scan2.nextInt();    // scan for user input and set it to y
System.out.println(y);    // print the value of y
Run Code Online (Sandbox Code Playgroud)

Scanner …

java java.util.scanner

11
推荐指数
1
解决办法
1万
查看次数

关闭BufferedReader和System.in

Reader rdr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(rdr);
String s;
s = br.readLine();
br.close();
Scanner sc = new Scanner(System.in);
s = sc.nextLine();
System.out.print(s);
Run Code Online (Sandbox Code Playgroud)

我注意到,如果我关闭BufferedReader,我将无法再从键盘插入输入,因为System.in某种程度上是关闭的.无论如何我可以保留br.close()(我需要它来删除文件),然后从键盘添加更多输入?

java input system.in bufferedreader

6
推荐指数
1
解决办法
6178
查看次数

为什么此代码会获得Java NoSuchElement异常?

我已经跟踪了这段代码,无法弄清楚如何修复它.运行代码时,为什么不提示用户输入而不是Java确定没有输入?错误跟踪如下.

import java.util.*;
public class SortAsInserted {

    public static void main(String[] args) {
        int array_size = GetArraySize();
        //System.out.println(array_size);
        String[] myArray = new String[array_size];
        for (int i = 0; i < array_size; i++){
            String next_string = GetNextString();
            System.out.println(next_string);
        }
    }



    //public static String[] SortInsert(String nextString){
        //}

    public static int GetArraySize(){
        Scanner input = new Scanner(System.in);
        System.out.print("How many items are you entering?: ");
        int items_in_array = input.nextInt();
        input.close();
        return items_in_array;


    }

    public static void PrintArray(String[] x) {
        for (int i = 0; …
Run Code Online (Sandbox Code Playgroud)

java java.util.scanner nosuchelementexception

3
推荐指数
1
解决办法
118
查看次数