读取文本文件并将字符串“ true / false”追加到现有行，并使用Java覆盖文件，但FileWriter无法解析

Question

我程序的目的是：

1）输入帐号并检查是否在坚持帐号行的文本文件accs.txt中存在>

2）输入文件的路径

3）读取文本文件的内容，如果存在输入，则在每行后附加“ true”，否则添加“ false”，然后覆盖文件并给出输出。

我完成了大部分工作，但是不明白为什么FileWriter无法解决：

import java.io.*;
import java.util.*;
public class ReadFromFile2 
    {

    public static void main(String[] args) throws IOException {

        //create object of a text file
        File file = new File("C:\\Users\\Artur\\Desktop\\accs.txt");

        BufferedReader br = new BufferedReader(new FileReader(file));

        //ask for user account input
        System.out.println("Enter your account number:");
        Scanner input = new Scanner(System.in);
        String account = input.nextLine();

        //read the file and check if account exists
        String st;
        while ((st = br.readLine()) !=null) {
            if(st.contains(account)) 

                System.out.println("Found");

                else System.out.println("Not found");
            break;
            }

        //enter a filename accs.txt and the path
        System.out.println("Enter file name:");
        Scanner inputname = new Scanner(System.in);
        String filename = input.nextLine();

        System.out.println("Enter path for file accs:");
        Scanner inputpath = new Scanner(System.in);
        String path = input.nextLine();

        //return path
        File fileaccounts = new File(path + "\\" + filename);
        System.out.println(fileaccounts);

        //read results, if exists - true, if not - false, then write file
        FileWriter fw = new FileWriter(file, true);

        BufferedWriter bw = new BufferedWriter(fw);
        String fileContent = "accs.txt";
        int lineNum = 0;

         while ((st = br.readLine()) != null) {

             if(st.contains(account))

                 st = st +"; true";

             else st = st +"; false";
             lineNum++;
             System.out.println(st);
             fileWriter.write(st);

             //FileWriter fw = new FileWriter("C:\\Users\\Artur\\Desktop\\newfile.txt");
             //fw.write(fileContent);
             fw.close();




         }
        }
    }
预期的输出应该是：

Enter your account number:
AA051245445454552117989
Found
Enter file name:
accs.txt
Enter path for file accs:
C:\Users\Artur\Desktop\\accs.txt
C:\Users\Artur\Desktop\accs.txt\accs.txt
LT647044001231465456; false
LT517044077788877777; false
LT227044077788877777; false
CC051245445454552117989; false
但是我修改了当前示例的代码，然后得到：

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
    fileWriter cannot be resolved

    at ReadFromFile2.main(ReadFromFile2.java:58)

我程序的目的是：1）输入帐号，并检查它是否存在于坚持帐号行的文本文件accs.txt中2）输入文件的路径3）读取...的内容

Answer 1

您将FileWriter对象声明为fw：