Question

import java.io.*;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args){
        Persona persona1 = new Persona();
        try{
            StringTokenizer st;
            BufferedReader br = new BufferedReader(new FileReader("entrada.txt"));
            String linea = br.readLine();
            PrintWriter pw = new PrintWriter(new FileWriter("datos.csv"));

            while(linea != null){
                st = new StringTokenizer(linea);
                persona1.setNombre(st.nextToken());
                persona1.setRFC(st.nextToken());
                persona1.setSueldoMensual(Double.parseDouble(st.nextToken());
                persona1.setPrimaVacacional(Double.parseDouble(st.nextToken()));
                persona1.setGastosHospitalarios(Double.parseDouble(st.nextToken()));
                persona1.setGastosFunerarios(Double.parseDouble(st.nextToken()));
                persona1.setSGMM(Double.parseDouble(st.nextToken()));
                persona1.setGastosHipotecarios(Double.parseDouble(st.nextToken()));
                persona1.setDonativos(Double.parseDouble(st.nextToken()));
                persona1.setAportacionRetiro(Double.parseDouble(st.nextToken()));
                persona1.setTransporteEscolar(Double.parseDouble(st.nextToken()));
                persona1.setNivelEducativo(st.nextToken());
                persona1.setColegiaturaTotal(Double.parseDouble(st.nextToken()));

                pw.println(persona1.getNombre() + "," + persona1.getRFC() + "," + persona1.getSueldoMensual()
            + "," + persona1.getPrimaVacacional() + "," + persona1.getGastosHospitalarios() + "," + persona1.getGastosFunerarios()
            + "," + persona1.getSGMM() + "," + persona1.getGastosHipotecarios() + "," + persona1.getDonativos()
            + "," + persona1.getAportacionRetiro() + "," + persona1.getTransporteEscolar()
            + "," + persona1.getNivelEducativo() + "," + persona1.getColegiaturaTotal());
            }
            br.close();
            pw.close();
        }
        catch(FileNotFoundException ex){
            System.out.println("Ocurrio un error " + ex);
        }
        catch(IOException ex){
            System.out.println("Ocurrio un error " + ex);
        }
    }
}

我的程序收到一个.txt文件，并在.csv文件中返回信息，但是当我运行它时会返回此错误：

Exception in thread "main" java.util.NoSuchElementException
    at java.util.StringTokenizer.nextToken(StringTokenizer.java:349)
    at Main.main(Main.java:26)

这没有意义，因为我有另一个程序做类似的事情，但我无法弄清楚问题是什么。

Answer 1

你的问题是没有令牌，你试图设置它，但是例外说没有这样的元素。

为了避免NoSuchElementException，您应该始终在StringTokenizer.hasMoreTokens()的帮助下检查是否有更多令牌。

Answer 2

尝试使用：

while (st.hasMoreTokens()) {
         //do things
     }

我的想法是，当标记生成器完成时，字符串最终为空字符串（“”），而不是空。

为什么我的代码返回此错误：java.util.NoSuchElementException？

2 个答案: