如果.txt文件位于以下路径中：MyProject \ src \ main \ java \ aPackage \ inventory.txt

您可以这样做：

String file = new File(new File("src/main/java/aPackage").getAbsoluteFile() + File.separator + "inventory.txt").toString();

或

String file = System.getProperty("user.dir") + File.separator + "src/main/java/aPackage"+ File.separator + "inventory.txt";

以下是使用您提供的代码的有效示例：

import java.util.StringTokenizer;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.text.DecimalFormat;

class InventoryItem {
    private String name;
    private int units;   // number of available units of this item
    private float price;  // price per unit of this item
    private DecimalFormat fmt;
    public InventoryItem (String itemName,int numUnits,float cost) {
        name = itemName;
        units = numUnits;
        price = cost;
        fmt = new DecimalFormat ("0.##");
    }
    public String toString()   {
        return name + ":\t" + units + " at " + price + " = " +
                fmt.format ((units * price));
    }
}
public class Inventory{
    //  Reads data about a store inventory from an input file,//  creating an array of InventoryItem objects,then prints them.
    public static void main (String[] args)   {
        final int MAX = 100;
        InventoryItem[] items = new InventoryItem[MAX];
        StringTokenizer tokenizer;
        String line,name;
        String file = new File(new File("src/main/java/aPackage").getAbsoluteFile() + File.separator + "inventory.txt").toString();
        int units,count = 0;
        float price;

        try{
            BufferedReader inFile = new BufferedReader(new FileReader(file));
            line = inFile.readLine();
            while (line != null) {
                tokenizer = new StringTokenizer (line);
                name = tokenizer.nextToken();
                try            {
                    units = Integer.parseInt (tokenizer.nextToken());
                    price = Float.parseFloat (tokenizer.nextToken());
                    items[count++] = new InventoryItem (name,units,price);
                }
                catch (NumberFormatException exception)            {
                    System.out.println ("Error in input. Line ignored:");
                    System.out.println (line);
                }
                line = inFile.readLine();
            }
            inFile.close();

            for (int scan = 0; scan < count; scan++)
                System.out.println (items[scan]);
        }
        catch (FileNotFoundException exception)      {
            System.out.println ("The file " + file + " was not found.");
        }
        catch (IOException exception)      {
            System.out.println (exception);
        }
    }
}

尝试创建一个新文件夹，我们现在将其称为“文本”。然后，您的代码将像：

//your code here
String line,name,file="texts\\inventory.txt";
//more code

希望这对您有所帮助！