Question

这个while循环只是永远循环。我查找了解决方案并尝试添加消耗输入的内容，但这没有帮助。 printf＆＃34; readDONEZO＆＃34;没有打印。

这是我的代码

public void read(Scanner stdin) {
    int sRow = 0;
    while ( stdin.hasNextLine() ) {
        String theLine = stdin.nextLine();
        String[] split = theLine.split(",");

        int size = split.length; //how many values in array = 3
        for(int i = 0; i < size ; i++){
            String value = split[i];
            int sColumn = i;
            setCellValue(sRow, sColumn, value);
            System.out.printf("%s", getCellValue(sRow,sColumn));
            if (i+1 != size) {
            System.out.printf(",");
            }
        }   
        sRow += 1;
        System.out.printf("\n");
    }
    System.out.printf("readDONEZO\n");
}

主要

import java.io.*;
import java.util.Scanner;

public class Main {

public static void main(String[] args) {

    int rows = 100;
    int columns = 26;

    StringSpreadsheet a = new StringSpreadsheet(rows, columns);

    Scanner stdin = new Scanner(System.in);
    a.read(stdin);
    System.out.printf("out of read\n");
    a.write();
}   
}

类

import java.util.Scanner;

public class StringSpreadsheet {

private int rows;
private int columns;
private String[][] cells;
private int allRows;
private int allColumns;

public StringSpreadsheet(int rows, int columns) {
    allColumns = 0;
    allRows = 0;
    this.rows = rows;
    this.columns = columns;
    cells = new String[this.rows][this.columns];
}

public void read(Scanner stdin) {
    while ( stdin.hasNextLine() ) {
        String theLine = stdin.nextLine();
        String[] split = theLine.split(",");

        allColumns = split.length; //how many values in array = 3
        for(int i = 0; i < allColumns ; i++){
            String value = split[i];
            int sColumn = i;
            setCellValue(allRows, sColumn, value);
            System.out.printf("%s", getCellValue(allRows,sColumn));
            if (i+1 != allColumns) {
            System.out.printf(",");
            }
        }   
        allRows += 1;
        System.out.printf("\n");
    }
    System.out.printf("readDONEZO\n");
}



public void write() {                                                           
    for (int i = 0 ; i < allRows ; i++){                                                    
        for(int j = 0 ; j < allColumns ; j++){                                                      
            String value = getCellValue(i, j);
            if ()
            System.out.printf("%s,", value);
        }
    }
}

public String getCellValue(int gRow, int gColumn) {
    return cells[gRow][gColumn];
}

public void setCellValue(int sRow, int sColumn, String value) {
    cells[sRow][sColumn] = value;
}
}

Answer 1

您的代码中的问题是您永远不会关闭扫描程序，因为stdin随时可以接收新输入。

出于这个原因，stdin.hasNextLine() while条件始终为true，它使while循环成为无限循环。如果您将扫描仪的输入（System.in）替换为工作站中文件的路径，则该示例将正常工作，因为该文件具有最后一行。

.hasNextLine（）永远循环

1 个答案: