我将如何添加一个return语句对于这一点，我该如何调用该方法？ [英] How would I add a return statement for this, and how do I call the method?

问题描述

public class InputFileData {
/**
 * @param inputFile a file giving the data for an electronic
 * equipment supplier’s product range
 * @return an array of product details
 * @throws IOException
 */
public static Product [] readProductDataFile(File inputFile) throws IOException {
// CODE GOES HERE (input data from a text file and sort into arraylists)
}

readProductDataFile 是用来读取一个文本文件，并将其存储在类型的数组产品[] 。提供的code无法改变，我需要与此code工作的一种方式。我已经成功地使文件读取和排序为数组列表在不同的类工作，但以这种方式运行它给我几个问题：

readProductDataFile is used to read a text file, and store it in an array of type Product[]. The code provided cannot be changed, I need a way that works with this code. I've managed to make file reading and sorting into array lists work in a different class, but running it in this way is giving me a couple of problems:

1）我不能调用从主类的<​​code> readProductDataFile 方法，因为如果不能找对方法（这绝对是在正确的包）。

1) I can't call the readProductDataFile method from the Main class, as if it can't find the method (it's definitely in the correct package).

2）我无法弄清楚如何格式化return语句，我已经尝试了很多不同的东西，但我看不出如何将它保存为数组类型产品[] 。

2) I can't figure out how to format the return statement, I've tried lots of different things but I just can't see how to store it as array type Product[].

我还没有提供具体的很多code到目前为止，因为我不想要的答案被交给我放在盘子里（这是任务的一部分，所以我不希望其他人做直上做到这一点对我来说），但会有人能够指出我在正确的方向来解决这个？

I haven't provided a lot of specific code so far because I don't want the answer to be handed to me on a platter (this is part of an assignment so I don't want other people to straight up do it for me), but would anyone be able to point me in the right direction to solve this?

要给出如何我现在在做一个想法，下面的测试code为我工作：

To give an idea of how I'm doing at the moment, the following test code worked for me:

ElectronicsEquipmentDemo 类：

public class ElectronicsEquipmentDemo {
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {
        Name inputFile = new Name();
        inputFile.privateName();
    }
}

名称类：

public class Name {
    public String privateName() {
        try {
            FileReader fr = new FileReader("myOutput.txt");
            BufferedReader br = new BufferedReader(fr);
            String str;

            while ((str = br.readLine()) != null) {
                char firstLetter = str.charAt(0);

                if (firstLetter == 'P') {
                    String[] list = str.split("/");
                    Arrays.toString(list);
                    String fullName = list[1] + " " + list[2] + " " + list[3] + "\n";
                    System.out.println(fullName);
                }
            }
            br.close();
        } catch (IOException e) {
            System.out.println("File not found");
        }
        return null;
    }
}

从一个文本文件中读取和，如果符合的 P 的开始，分成数组，并打印出指定的值（虽然我尝试添加return语句使它只返回第一线，所以还在挣扎那里）。

Which reads from a text file and, if the line begins with P, splits into arrays and prints out specified values (although my attempt to add a return statement made it only return the first line, so still struggling there).

推荐答案

这应该这样做：

public class Name {
    public String[] privateName(){
        String[] list;
        try {
            FileReader fr = new FileReader("myOutput.txt");
            BufferedReader br = new BufferedReader(fr);

            String str;

            while ((str = br.readLine()) != null) {
                char firstLetter = str.charAt(0);

                if (firstLetter == 'P'){

                    list = str.split("/");

                    //Arrays.toString(list);
                    String fullName = list[1] + " " + list[2] + " "+ list[3] + "\n";
                    System.out.println(fullName);

                }

            }
            br.close();
        } catch (IOException e) {
            out.println("File not found");
        }
        return list;

    }
}

编辑：固定的范围界定问题

fixed scoping issue.

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