pls for some hints am really confused

Question about the task

Reading and writing to a file: Human

Java Core, Level 10, Lesson 2

Archived

Implement the logic for file IO for the Human class.
The Human class's name field can't be empty.
The main method exists just for you and is not involved in testing the solution.

Requirements:

The read/write logic in the save/load methods must work correctly when the assets list is empty.
The read/write logic in the save/load methods must work correctly when the name field and assets list are not empty.
The Solution.Human class should not support the Serializable interface.
The Solution.Human class must be public.
The Solution.Human class should not support the Externalizable interface.

package com.codegym.task.task20.task2001; import java.io.*; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /* Reading and writing to a file: Human */ public class Solution { public static void main(String[] args) { // Update the string passed to the createTempFile method based on the path to a file on your hard drive try { File yourFile = File.createTempFile("your_file_name", null); OutputStream outputStream = new FileOutputStream(yourFile); InputStream inputStream = new FileInputStream(yourFile); Human smith = new Human("Smith", new Asset("home", 999_999.99), new Asset("car", 2999.99)); smith.save(outputStream); outputStream.flush(); Human somePerson = new Human(); somePerson.load(inputStream); inputStream.close(); // Check that smith is equal to somePerson } catch (IOException e) { // e.printStackTrace(); System.out.println("Oops, something is wrong with my file"); } catch (Exception e) { // e.printStackTrace(); System.out.println("Oops, something is wrong with the save/load method"); } } public static class Human { public String name; public List<Asset> assets = new ArrayList<>(); public Human() { } public Human(String name, Asset... assets) { this.name = name; if (assets != null) { this.assets.addAll(Arrays.asList(assets)); } } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Human human = (Human) o; if (name != null ? !name.equals(human.name) : human.name != null) return false; return assets != null ? assets.equals(human.assets) : human.assets == null; } @Override public int hashCode() { int result = name != null ? name.hashCode() : 0; result = 31 * result + (assets != null ? assets.hashCode() : 0); return result; } public void save(OutputStream outputStream) throws Exception { // Implement this method } public void load(InputStream inputStream) throws Exception { // Implement this method } } }

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Kinomax

Level 22 , Warsaw, Poland

7 July 2019, 21:32

i suggest using a PrintWrite object for saving data. dont forget about flush in method save.

robin

Level 23 , Lublin, Poland

17 June 2019, 09:01

It looks like you haven't even tried to do anything... Have a go at those save and load methods. For save I suggest you: 1) check if the Human object to be saved has some Assets, and save it to some variable 2) create some kind of writer to write the data (including the variable mentioned above). I used PrintWriter 3) use the writer to write all the data And for the load method: 1) create some reader to read the data. I used Scanner 2) check if the Human object to be loaded has any Assets (based on the variable you saved earlier) 3) go through the data read by the reader and save them to this object Remember to close the reader/writer at the end. If you have some problems with any of these steps, let me know, I'll try to help. Good luck!

Bill Nguyen

Level 22 , Ho Chi Minh, Vietnam

22 August 2019, 17:59

I followed your instruction but I didn't pass. Please help!

public void save(OutputStream outputStream) throws Exception {
            // Implement this method
            PrintWriter writer = new PrintWriter(outputStream);
            writer.println(name);
            String isAssetPresent = assets != null ? "Yes" : "No";
            writer.println(isAssetPresent);

            if (assets != null) {
                for (Asset e : assets) {
                    writer.println(e.getName());
                    writer.println(e.getPrice());
                }
            }
            writer.flush();
            writer.close();
        }

        public void load(InputStream inputStream) throws Exception {
            // Implement this method
            Scanner scanner = new Scanner(inputStream);
            name = scanner.nextLine();
            String isAssetPresent = scanner.nextLine();
            if (isAssetPresent.equals("Yes")) {
                while(scanner.hasNext()) {
                    Asset asset = new Asset(scanner.nextLine(), scanner.nextDouble());
                    assets.add(asset);
                }
                scanner.close();
            }
        }

Bill Nguyen

Level 22 , Ho Chi Minh, Vietnam

23 August 2019, 10:25

I passed. Thank you very much.

Alexandros Kapriniotis

Level 24 , greece, Greece

17 September 2019, 12:29

Hi, i am also struggling with this task, can you help me solve it?

Brandon Horvatic

Level 27 , Johannesburg, South Africa

2 October 2019, 15:34

the above code works, just change the "Yes" to "yes" on line 23 and on line 25, change the scanner.nextDouble() to Double.parseDouble(scanner.nextLine());