Android - Loop through multiline text file and extract data from its categories after the colon and store inside a class variable

Question

I am trying to extract a data from a raw text file in my raw directory by reading it and getting the string after the colon preceded by a category and storing it in a class variable. The raw text file is as follows:

category:AI
photo:ai4.png
title:'I will destroy humans': Humanoid AI robot Sophia gets Saudi citizenship
website:https://www.deccanchronicle.com/lifestyle/viral-and-trending/111117/i-will-destroy-humans-humanoid-ai-robot-sophia-gets-saudi-citizenship.html
date:11-11-2017
category:cybersecurity
photo:cyber3.png
title:WhatsApp and Telegram media files aren't so secure
website:https://www.theverge.com/2019/7/15/20692184/whatsapp-telegram-media-files-android-messaging-encryption
date:15-07-2019

I want to be able to read the first line and check what category it is, if the category is photo, I want to store the ai4.png in the class variable related to it. After it reaches date and the date data is stored in the date class variable. It will instantiate a new class and begin the process again with a new class.

The class is as follows:

public class Link{
    private String title;
    private String imageName;
    private String url;

    Link(String t,String i,String u){
        this.title=t;
        this.imageName=i;
        this.url=u;
    }
    public String getTitle() {
            return title;
        }

        public void setTitle(String title) {
            this.title = title;
        }

        public String getImageName() {
            return imageName;
        }

        public void setImageName(String imageName) {
            this.imageName = imageName;
        }
    public String getURL(){
        return url;
    }
    public void setURL(String url){
        this.url = url;
    }

}

So by reading the text file, if it is title preceded by colon, it will assign the title text after the colon to the title class variable.

Sorry, I am new to android and Java in general, any help is appreciated. Thanks for reading!

Answer 1

I have found a solution.

        InputStream input = getResources().openRawResource(R.raw.news_items);
        String _final="";
        Scanner scanner = new Scanner(input);
        while(scanner.hasNext()){
            String line = scanner.nextLine();

            String[] pieces = line.split(":",2);
            _final+=pieces[1]+"\n";
        }

First, I get the raw text file from the raw directory and store it under InputStream input variable.

After that,I pass the InputStream variable into a Scanner variable to read it as a text file to my understanding, please correct me if I am wrong!

In the while loop, while there it isn't end-of-file (EOF), get the line of text. Split it at the colon(:), and since I want to get Web URL's also, split at the first instance of colon hence the 2 in .split(":",2).

Lastly, append it the _final text variable, this is purely for testing sake. I can modify it to pass these variables into class variables with some effort.

Answer 2

As I see it, your problem consists of 2 parts.

First one is to read the file from Android storage and
Second is to read the text and parse into an array/list of class objects.

For the first part, I would recommend looking at the following stackoverflow answer:
How can I read a text file in Android?

As for the second part, use the following code snippet:

    String fileContents = "category:AI\n" +
            "photo:ai4.png\n" +
            "title:'I will destroy humans': Humanoid AI robot Sophia gets Saudi citizenship\n" +
            "website:https://www.deccanchronicle.com/lifestyle/viral-and-trending/111117/i-will-destroy-humans-humanoid-ai-robot-sophia-gets-saudi-citizenship.html\n" +
            "date:11-11-2017\n" +
            "category:cybersecurity\n" +
            "photo:cyber3.png\n" +
            "title:WhatsApp and Telegram media files aren't so secure\n" +
            "website:https://www.theverge.com/2019/7/15/20692184/whatsapp-telegram-media-files-android-messaging-encryption\n" +
            "date:15-07-2019";
    String[] arrayOfContents = fileContents.split("\n");
    List<Link> arrayOfLinks = new ArrayList<>();
    boolean isFirstSection = true;
    Link link = new Link();

    for (String content : arrayOfContents) {
        String[] splitVal = content.split(":");

        switch (splitVal[0].toLowerCase()) {
            case "category":
                if (isFirstSection) {
                    isFirstSection = false;
                } else {
                    arrayOfLinks.add(link);
                }
                link = new Link();
                link.setCategory(splitVal[1]);
                break;
            case "date":
                link.setDate(splitVal[1]);
                break;
            case "photo":
                link.setPhoto(splitVal[1]);
                break;
            case "title":
                link.setTitle(splitVal[1]);
                break;
            case "website":
                link.setWebsite(splitVal[1]);
                break;
            default:
                break;
        }
    }
    arrayOfLinks.add(link);

fileContents variable will actually have the text file contents that you read from the storage.

Also, below is the Class Link which will hold all the data in the end:

public class Link {

private String Category;
private String Photo;
private String Title;
private String Website;
private Date Date;

public Link() {
}

public void setCategory(String category) {
    Category = category;
}

public void setPhoto(String photo) {
    Photo = photo;
}

public void setTitle(String title) {
    Title = title;
}

public void setWebsite(String website) {
    Website = website;
}

public void setDate(String date) {
    try {
        Date = new SimpleDateFormat("dd-MM-yyyy").parse(date);
    } catch (Exception e) {
        Date = null;
    }
}}

In the end, you will have the complete data in arrayOfLinks variable.

Hope this solves your query.