Reading CSV File In Android App

New coder for Android Studio. I've been researching how to read CSV files and this works best for my needs. (s0, s1, etc. Strings were defined at the beginning of my program).

    File fileDirectory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
    File fileToGet = new File(fileDirectory,"aFileName.csv");
        try {
            BufferedReader br = new BufferedReader(new FileReader(fileToGet));
            String line;
            while ((line = br.readLine()) !=null) {
                String[] tokens = line.split(",");
                s0=tokens[0].toString(); s1=tokens[1].toString(); s2=tokens[2].toString();
                s3=tokens[3].toString(); s4=tokens[4].toString(); s5=tokens[5].toString();
                                                  }
            }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

The following snippet reads a CSV file from the raw resources folder (which will be packed into your .apk file upon compilation).

Android by default does not create the raw folder. Create a raw folder under res/raw in your project and copy your CSV File into it. Keep the name of the CSV file lower case and convert it into text format when asked. My CSV file name is welldata.csv.

In the snippet, WellData is the model class (with constructor, getter and setter) and wellDataList is the ArrayList to store the data.

private void readData() {
    InputStream is = getResources().openRawResource(R.raw.welldata);
    BufferedReader reader = new BufferedReader(
            new InputStreamReader(is, Charset.forName("UTF-8")));
    String line = "";

    try {
        while ((line = reader.readLine()) != null) {
           // Split the line into different tokens (using the comma as a separator).
            String[] tokens = line.split(",");

            // Read the data and store it in the WellData POJO.
            WellData wellData = new WellData();
            wellData.setOwner(tokens[0]);
            wellData.setApi(tokens[1]);
            wellData.setLongitude(tokens[2]);
            wellData.setLatitude(tokens[3]);
            wellData.setProperty(tokens[4]);
            wellData.setWellName(tokens[5]);
            wellDataList.add(wellData);

            Log.d("MainActivity" ,"Just Created " + wellData);
        }
    } catch (IOException e1) {
        Log.e("MainActivity", "Error" + line, e1);
        e1.printStackTrace();
    }
}

This worked for me in Kotlin. You will need to place the myfile.csv file in the res/raw folder, creating the folder if it isn't there.

val inputStream: InputStream = resources.openRawResource(R.raw.myfile)
val reader = BufferedReader(InputStreamReader(inputStream, Charset.forName("UTF-8")))
reader.readLines().forEach {

    //get a string array of all items in this line
    val items = it.split(",")

    //do what you want with each item
}

Try OpenCSV - it will make your life easier.

First, add this package to your gradle dependencies as follows

implementation 'com.opencsv:opencsv:4.6'

Then you can either do

import com.opencsv.CSVReader;
import java.io.IOException;
import java.io.FileReader;


...

try {
    CSVReader reader = new CSVReader(new FileReader("yourfile.csv"));
    String[] nextLine;
    while ((nextLine = reader.readNext()) != null) {
        // nextLine[] is an array of values from the line
        System.out.println(nextLine[0] + nextLine[1] + "etc...");
    }
} catch (IOException e) {

}

or

CSVReader reader = new CSVReader(new FileReader("yourfile.csv"));
List myEntries = reader.readAll();

---

Edit after comment

try {
    File csvfile = new File(Environment.getExternalStorageDirectory() + "/csvfile.csv");
    CSVReader reader = new CSVReader(new FileReader(csvfile.getAbsolutePath()));
    String[] nextLine;
    while ((nextLine = reader.readNext()) != null) {
        // nextLine[] is an array of values from the line
        System.out.println(nextLine[0] + nextLine[1] + "etc...");
    }
} catch (Exception e) {
    e.printStackTrace();
    Toast.makeText(this, "The specified file was not found", Toast.LENGTH_SHORT).show();
}

If you want to package the .csv file with the application and have it install on the internal storage when the app installs, create an assets folder in your project src/main folder (e.g., c:\myapp\app\src\main\assets\), and put the .csv file in there, then reference it like this in your activity:

String csvfileString = this.getApplicationInfo().dataDir + File.separatorChar + "csvfile.csv"
File csvfile = new File(csvfileString);