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Question about the task

Prices 2

Java Core, Level 8, Lesson 11

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I tested on my files and it is working but not passing third and forth condition. Can someone see mistake ?

if (args.length > 0 && (args[0].equals("-u") || args[0].equals("-d"))) {

            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

            String file = reader.readLine();

            reader.close();

            FileInputStream inputStream = new FileInputStream(file);

            BufferedReader fileReader = new BufferedReader(new InputStreamReader(inputStream));

            Map<String, String> map = new TreeMap<>();

            while (fileReader.ready()) {

                String line = fileReader.readLine();

                String tempID = line.substring(0, 8);
                String rest = line.substring(8);

                map.put(tempID, rest);

            }

            fileReader.close();
            inputStream.close();

            int mapSize = map.size();

        String id = args[1];

        if (id.length() < 8) {

            for (int i = id.length(); i < 8; i++) {

                id += " ";

            }
        }

        String empty = "";

        FileOutputStream outputStreamDelete = new FileOutputStream(file);
        outputStreamDelete.write(empty.getBytes());
        outputStreamDelete.close();

        FileOutputStream outputStream = new FileOutputStream(file, true);

            switch (args[0]) {

                case "-u":

                    int countU = 0;

                    String productName = args[2];

                    if (productName.length() < 30) {

                        for (int i = productName.length(); i < 30; i++) {

                            productName += " ";

                        }
                    }

                    String price = args[3];

                    if (price.length() < 8) {

                        for (int i = price.length(); i < 8; i++) {

                            price += " ";

                        }
                    }

                    String quantity = args[4];

                    if (quantity.length() < 4) {

                        for (int i = quantity.length(); i < 4; i++) {

                            quantity += " ";

                        }
                    }

                    String updatedValue = productName + price + quantity;

                for (Map.Entry<String, String> data : map.entrySet()) {

                    String key = data.getKey();
                    String oldDAta = data.getValue();

                    if (key.equals(id)) {

                        countU++;
                        String update = key + updatedValue;

                        outputStream.write(update.getBytes());

                        if (countU < mapSize) {
                            outputStream.write(System.lineSeparator().getBytes());
                        }

                    }else {
                        countU++;

                        String old = key + oldDAta;

                        outputStream.write(old.getBytes());

                        if (countU < mapSize) {
                            outputStream.write(System.lineSeparator().getBytes());
                        }

                    }
                }

                outputStream.close();

                break;

                case "-d" :

                    map.remove(id);

                    int countD = 0;

                    for (Map.Entry<String, String> data : map.entrySet()) {

                        String key = data.getKey();
                        String oldDAta = data.getValue();

                        countD++;

                            String allArguments = key + oldDAta;

                            outputStream.write(allArguments.getBytes());
                        if (countD < mapSize) {
                            outputStream.write(System.lineSeparator().getBytes());
                        }
                    }

                    outputStream.close();

                    break;
            }
        }
    }

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

The program runs with one of the following sets of arguments:
-u id productName price quantity
-d id

Argument values:
where id is 8 characters
productName is 30 characters
price is 8 characters
quantity is 4 characters
-u updates the data for the product with the specified id
-d performs the physical deletion of the product with the specified id (all data related to the passed id)

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

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.
When you run the program without arguments, the product list must remain unchanged.
When the program is started with the arguments "-u id productName price quantity", the product information in the file should be updated.
When the program is started with the arguments "-d id", the line for the product with the specified id should be removed from the file.
The file streams must be closed.

package com.codegym.task.task18.task1828; /* Prices 2 */ import java.io.*; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; public class Solution { public static void main(String[] args) throws IOException { if (args.length > 0 && (args[0].equals("-u") || args[0].equals("-d"))) { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String file = reader.readLine(); reader.close(); FileInputStream inputStream = new FileInputStream(file); BufferedReader fileReader = new BufferedReader(new InputStreamReader(inputStream)); Map<String, String> map = new HashMap<>(); while (fileReader.ready()) { String line = fileReader.readLine(); String tempID = line.substring(0, 8); String rest = line.substring(8); map.put(tempID, rest); } fileReader.close(); inputStream.close(); String id = args[1]; String productName = args[2]; String price = args[3]; String quantity = args[4]; String updatedValue = productName + price + quantity; String empty = ""; FileOutputStream outputStreamDelete = new FileOutputStream(file); outputStreamDelete.write(empty.getBytes()); outputStreamDelete.close(); FileOutputStream outputStream = new FileOutputStream(file, true); switch (args[0]) { case "-u": ArrayList<String> lines = new ArrayList<>(); for (Map.Entry<String, String> data : map.entrySet()) { String key = data.getKey(); String oldDAta = data.getValue(); if (key.equals(id)) { String update = key + updatedValue; lines.add(update); }else { String old = key + oldDAta; lines.add(old); } } for (int i=0; i < lines.size(); i++) { if (i == lines.size()-1) { outputStream.write(lines.get(i).getBytes()); } else { outputStream.write(lines.get(i).getBytes()); outputStream.write(System.lineSeparator().getBytes()); } } outputStream.close(); break; case "-d" : map.remove(id); ArrayList<String> lines2 = new ArrayList<>(); for (Map.Entry<String, String> data : map.entrySet()) { String key = data.getKey(); String oldDAta = data.getValue(); if (id.equals(key)) { } else { String allArguments = key + oldDAta; lines2.add(allArguments); } } for (int i=0; i < lines2.size(); i++) { if (i == lines2.size()-1) { outputStream.write(lines2.get(i).getBytes()); } else { outputStream.write(lines2.get(i).getBytes()); outputStream.write(System.lineSeparator().getBytes()); } } outputStream.close(); break; } } } }

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Goran

Level 41 , Belgrade, Serbia

20 June 2020, 15:29

I have changed on line 28 HashMap to TreeMap and lines 48, 49, 50 put inside switch in case "-u". Tested everything looks good in my files but still not passing! I am losing my mind here

Thomas

Level 41 , Bayreuth, Germany

21 June 2020, 16:29

useful

OK, when testing your code I've seen a few problems. First you need to move line 48-51 into the -u block. Otherwise you'd get an exception if you delete. t least I did. Your trying to match ids to either delete or update but you never will get a match, even if the id's are (visibly) the same. Problem is, that line.substring(0, 8); grabs additonal whitespace that you ignore (but it's there). Just use a trim command to get rid of that -> line.substring(0, 8).trim(); When you write the data back to the file you don't keep the format. 8 characters for the id, 30 for the product name etc. In my solution it looks that way table.add(String.format("%-8s%-30s%-8s%-4s", idToUpdate, name, price, quantity)); And the last thing I have seen is, that you don't keep the order when writing back the data. However I don't know if that is necessary for validation. Ahh, I just see that you identified some of the probs yourself... never mind then ;)

Goran

Level 41 , Belgrade, Serbia

28 June 2020, 11:13

Yeah I thought that I have fixed order of my list along with moving lines 48-51 but i didn't . I made longer list and saw problem, writing back in table gets all mixed up. Just need to figure out how to fix order. BUT MANY THANKS FOR INFO THAT ID PRODUCT NAME QUANTITY AND PRICE ARE NOT CORRECT LENGTH. I understood task that they are correct length.

Goran

Level 41 , Belgrade, Serbia

28 June 2020, 11:40

I have edited first post on top, case my code exceeds number of characters in comment. I fix everything and still not passing. I tested code on my pc, with list with 9 lines. And everything is correct in order, length but still getting this error for "-u" case: "The item with the updated data should be on the same line in the file." Going mad here

Thomas

Level 41 , Bayreuth, Germany

28 June 2020, 13:12

solution

The TreeMap changes the order of the elements in map. Same may happen with a HashMap. So maybe you want to try a LinkedHashMap?

Goran

Level 41 , Belgrade, Serbia

12 July 2020, 08:20

Thank you man ! This solved my problem. I was using TreeMap but no lucky and LinkedHashMap solved it!