我是Java的新手,我遇到一个错误令我震惊...错误是:

Exception in thread "main" java.lang.NullPointerException
    at BancA.carica(BancA.java:30)
    at BancA.main(BancA.java:46)


我需要从txt文件中加载一些值...这是由一个ID(Cliente1等),第一个数字(付款)列表和第二个(付款)列表组成的...我决定区分这两个类别将它们分隔为“-” ...但是readLine()似乎读错了一行,或者忽略了我的“ while”语句...无论如何,这是我的代码,您的帮助我们将非常感激:-)

import java.io.*;
import java.util.*;
import java.lang.*;

public class BancA{
    private static final String CLIENTI = ("Clienti.txt");
    private static ArrayList <Conto> conto = new ArrayList <Conto>();
    public static void carica(){
        BufferedReader bc;
        Conto co = new Conto();
        String tmp, tmp1, tmp2;
        try{
            bc = new BufferedReader(new FileReader(CLIENTI));
            tmp = bc.readLine();
            while(tmp!=null){
            co.setId(tmp);
            tmp1 = bc.readLine();
            while(!(tmp1.equals("-"))){
                co.setBonifico(Integer.parseInt(tmp1));
                tmp1 = bc.readLine();
            }
            tmp2 = bc.readLine();
            while(!(tmp2.equals("-"))){
                co.setVersamento(Integer.parseInt(tmp2));
                tmp2 = bc.readLine();
            }
                conto.add(co);
                co = new Conto();
                tmp = bc.readLine();
            }
            System.out.println(conto);
        }
        catch(IOException e){
            e.printStackTrace();
        }
    }
public static void main(String [] args){
    carica();
}
}


这是另一类:

import java.util.*;
public class Conto{
public String id;
public LinkedList <Integer> bonifico = new LinkedList <Integer>();
public LinkedList <Integer> versamento = new LinkedList <Integer>();
public Conto(){
}
public void setId(String i){
    id = i;
}
public void setBonifico(int b){
    bonifico.add(b);
}
public void setVersamento(int v){
    versamento.add(v);
}
public String getId(){
    return id;
}
public LinkedList <Integer> getBonifico(){
    return bonifico;
}
public LinkedList <Integer> getVersamento(){
    return versamento;
}
public String toString(){
    String str = ("\nId: " +id+ "\nBonifico: " +bonifico+ "\nVersamento:+versamento);
    return str;
}
 }


这是我的Clienti.txt文件:

 Cliente1
 1
 2
 3
 -
 41
 52
 33
 90
 -
 Cliente2
 4
 -
 89
 3
 1

最佳答案

第二个readline()可能遇到EOF,并且在这种情况下tmp2可能是null,这导致NullPointerException

while(!(tmp2.equals("-")))更改为while (tmp2 != null && !tmp2.equals("-"))可解决您的问题。

07-26 01:06