It doesn't even validate

Question about the task

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It says there is a problem with line 47 method strip() and when I gray it out next problem is with line 55 method repeat(), please help me

CrUD for a table inside a file.
Read a file name for CrUD operations from the console.

The program is started with the following arguments:
-c productName price quantity

Argument values:
where id is 8 characters.
productName is 30 characters.
price is 8 characters.
quantity is 4 characters.
-c adds the product with the specified parameters to the end of the file, and generates an id by incrementing the maximum id found in the file.

The file data is stored in the following order (without separating spaces):
id productName price quantity

Each data field is padded with spaces up to its length.

Before adding a new line, re-write all of its contents to the file.

Example:
19847 Swim trunks, blue 159.00 12 198479 Swim trunks, black with printe173.00 17 19847983Snowboard jacket with reflecti10173.991234

Requirements:

The program should read a file name for CrUD operations from the console.
The Solution class should not use static variables.
When you run the program without arguments, the product list must remain unchanged.
When the program is run with the arguments "-c productName price quantity", a new line with the corresponding product should be added to the end of the file.
The product must have the next id after the maximum id found in the file.
The format of the new product line must precisely match that format specified in the task.
The file streams must be closed.

package com.codegym.task.task18.task1827; /* Prices */ import java.io.*; import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String fileName = reader.readLine(); reader.close(); FileInputStream fis = new FileInputStream(fileName); FileWriter fw = new FileWriter(fileName, true); String op = args[0]; String productName = args[1]; String price = args[2]; String quantity = args[3]; if(op.equals("-c")) { String line; String id = formatId(calculateNewId(fis)); productName = formatProductName(productName); price = formatPrice(price); quantity = formatQuantity(quantity); line = "" + id + productName + price + quantity; fw.write(line); } fis.close(); } private static String calculateNewId(FileInputStream fis) throws IOException { String line; int maxId = 0; BufferedReader br = new BufferedReader(new FileReader(String.valueOf(fis)), 8); while((line = br.readLine()) != null){ //line = line.strip(); int id = Integer.parseInt(line); if (maxId<id){ maxId = id; } } maxId += 1; String newMaxId = Integer.toString(maxId); StringBuilder newStr = new StringBuilder(); newStr.append(" ".repeat(8 - Math.min(newMaxId.length(), 8))); return newStr.toString(); } private static String formatString(String str, int limit) { StringBuilder newStr = new StringBuilder(); for(int i = 0; i < Math.min(str.length(), limit); i++){ newStr.append(str.charAt(i)); } newStr.append(" ".repeat(limit - Math.min(str.length(), limit))); return newStr.toString(); } private static String formatQuantity(String quantity) { return formatString(quantity, 4); } private static String formatPrice(String price) { return formatString(price, 8); } private static String formatProductName(String productName) { return formatString(productName,30); } private static String formatId(String id) { return formatString(id,8)+1; } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

2 February 2021, 18:10

-Line 19: Don't pass true into the constructor of any writer object unless specifically told to do so. The validation system will fail your code every time for doing that. This task also specifically says "Before adding a new line, re-write all of its contents to the file." That requirement means the code needs to read every single item from the file, save them, and then rewrite them back to the file. This means you will need to rework this code because it is not doing that. Line 43, passing in the String.valueOf(fis) won't work. The String that this results in is the object's ID in memory, not the file that the object reads from. Passing that in will throw a FileNotFoundException every time. Also,you shouldn't pass in 8. It looks like you expect that this will cause the reader to read only the first 8 chars of each line, but all this is doing is setting the internal buffer to size 8. Doing this will lose the efficiency that the BufferedReader allows. Line 46: Passing 'line' into Integer.parseInt() will throw an exception because it expects the String to be a number while line, as pointed out above will not just be the first 8 chars but would be the full id, product name, price, and amount. Lines 55 and 68: The String.repeat() method does not exist until Java 11. Codegym uses Java 8. This means that you can not use this method. In intelliJ you should set the "Project Language Level" of your code gym tasks in the project settings to 8. Go to "File>Project Structure" make sure that you are on the "Project" sub menu and you can set the language level in there. You can avoid this problem in the future by doing that. Use this bit of code to replave the method:

private static String formatString(String str, int limit) {
   StringBuilder newStr = new StringBuilder(str);

   while(newStr.length() < limit) newStr.append(" ");

   return newStr.toString();
}