java My bufferedread是否只读取文件的第一行？

Question

我在代码中使用的bufferedreader似乎只读取代码的第一行。有人能帮我解决这个问题吗？我已经试了很久了

import java.util.Scanner;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.BufferedReader;

public class Task2Recipe {

    private static String Ingredient;
    private static String ServingNumber;


    public static void main(String[] args) {

        Scanner user_input = new Scanner(System.in);
        System.out.println("Hello. If you would like to write a new recipe, please type in 'write', if you would like to change and view a recipe, please type in 'read'");
        String choice = user_input.next();
        user_input.nextLine();

        if (choice.equals("write")) {
            write();
        }

        if (choice.equals("read")) {
            read();
        }
    }

    public static void write() {

        try {
            FileWriter Task2Recipe = new FileWriter("P:/Year 11/GCSE Computing/A453/Task 2/Recipe.txt");
            BufferedWriter recipe = new BufferedWriter(Task2Recipe);
            Scanner user_input = new Scanner(System.in);

            System.out.println("Please enter the name of your recipe, if more than 1 word, seperate your words with a dash");
            String RecipeName = user_input.next();
            recipe.write("Name of recipe: " + RecipeName);
            recipe.newLine();

            System.out.println("Please enter the number of people your recipe serves");
            ServingNumber = user_input.next();
            recipe.write(ServingNumber);
            recipe.newLine();

            System.out.println("Please enter the name of your first ingredient, the quantity and units separated with a comma");
            Ingredient = user_input.next();
            recipe.write(Ingredient);
            recipe.newLine();

            System.out.println("Do you want to enter another ingredient? yes/no? Please type in either in lower case");
            String choice2 = user_input.next();

            user_input.nextLine();
            while (choice2.equals("yes")) {

                System.out.println("Please enter the name of your ingredient, the quantity and units separated with a comma");
                Ingredient = user_input.nextLine();
                recipe.write(Ingredient);

                System.out.println("Do you want to enter another ingredient? yes/no? Please type in either in lower case");
                choice2 = user_input.next();
                user_input.nextLine();
            }
            recipe.close();
        } catch (Exception e) {
            System.out.println("A write error has occured");

        }
    }

    public static void read() {

        try {
            Scanner user_input = new Scanner(System.in);
            FileReader file = new FileReader("P:Year 11/GCSE Computing/A453/Task 2/Recipe.txt");
            BufferedReader buffer = new BufferedReader(file);

            System.out.println("Would you like to change the serving number of your recipe, type in 'yes' to proceed, type in 'no'");
            String choice3 = user_input.next();
            user_input.nextLine();
            while (choice3.equals("yes")) {

                String line;
                System.out.println("Please enter the new serving number");
                int NewServingNumber = user_input.nextInt();

                int counter = 0;

                while ((line = buffer.readLine()) != null) {

                    counter++;

                    if (counter == 2) {
                    }

                    if (counter > 3) {

                        String[] word = Ingredient.split(",");
                        int Quantity = Integer.parseInt(word[1]);
                        int ServingNumberInt = Integer.parseInt(ServingNumber);
                        int Multiplier = ServingNumberInt / Quantity;
                        int NewQuantity = (Multiplier * NewServingNumber);

                        System.out.println("Your new quantity is " + NewQuantity);
                    }
                }

                System.out.println(line);

                buffer.close();
            }
        } catch (Exception e) {
            System.out.println("A read error has occured");
        }
    }
}

我的意见是：

applep-用于配方名称

10-服务号码

苹果，10个，苹果-对于配料，我只添加了1种配料

当我反复阅读我的文件并更改配方服务编号时，它不起作用，并出现“读取错误”。此外，为了测试这个问题，我打印了变量'line'，它似乎只读取第一行

提前谢谢

Answer 1

你有两个独立的案例——一个用于阅读，一个用于写作。如果在一种情况下，您指定了值​​对于变量，这并不意味着在其他情况下可以读取它们。此外，计数器设置不正确。请尝试以下代码-

while((line = buffer.readLine()) !=null) {
    counter++;
    if (counter == 3) {
        //String[]word = Ingredient.split(",");
        String[]word = line.split(",");

        int Quantity = Integer.parseInt(word[1]);
        //int ServingNumberInt = Integer.parseInt();
        int Multiplier = NewServingNumber / Quantity;
        int NewQuantity = (Multiplier * NewServingNumber);

        System.out.println("Your new quantity is " + NewQuantity);   
    }

}

它给出了-

Hello. If you would like to write a new recipe, please type in 'write', if you would like to change and view a recipe, please type in 'read'
read
Would you like to change the serving number of your recipe, type in 'yes' to proceed, type in 'no'
yes
Please enter the new serving number
10
Your new quantity is 10