How to parse CSV file into an array in Android Studio

Question

i'm wondering how to parse a CSV file and just store the contents into an array. My csv file looks something like this:

1,bulbasaur,1,7,69,64,1,1
2,ivysaur,2,10,130,142,2,1

I only want the names, so the second field. I want to store all of these items in the csv into an array or arraylist of string.

Any ideas how to do this?

Any help would be greatly appreciated!

Answer 1

I extended Sharma's answer to making the core class more flexible in a variety of conditions of the CSV file. I prefer the builder design pattern for configuring how to read the CSV file.

public class CSVFile {
    private static final Charset UTF8 = Charset.forName("UTF-8");
    private final static String DEFAULT_DELIMITER = ",";

    private InputStream inputStream;
    private Charset charset;
    private String delimiter;
    private boolean ignoreHead;

    public CSVFile(InputStream inputStream) {
        this.inputStream = inputStream;
        this.charset = UTF8;
        this.delimiter = DEFAULT_DELIMITER;
        this.ignoreHead = false;
    }

    public CSVFile setCharset(Charset charset) {
        this.charset = charset;
        return this;
    }

    public CSVFile setDelimiter(String delimiter) {
        this.delimiter = delimiter;
        return this;
    }

    public CSVFile ignoreHead() {
        ignoreHead = true;
        return this;
    }

    public List<String[]> read() {
        boolean firstRow = true;
        List<String[]> resultList = new ArrayList<>();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, charset));
        try {
            String csvLine;
            while ((csvLine = reader.readLine()) != null) {
                if (firstRow) {
                    firstRow = false;

                    if (ignoreHead) {
                        continue;
                    }
                }

                String[] row = csvLine.split(delimiter);
                resultList.add(row);
            }
        } catch (IOException ex) {
            throw new RuntimeException("Error in reading CSV file: " + ex);
        } finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                throw new RuntimeException("Error while closing input stream: " + e);
            }
        }
        return resultList;
    }
}

Answer 2

A better CSV parser handles quoted fields

    import android.content.Context;
    import android.widget.Toast;
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.List;

    public class CSVReader {
        private class StringDArray {
            private String[] data=new String[0];
            private int used=0;
            public void add(String str) {
                if (used >= data.length){
                    int new_size= used+1;
                    String[] new_data=new String[new_size];
                    java.lang.System.arraycopy( data,0,new_data,0,used);
                    data=new_data;
                }
                data[used++] = str;
            }
            public int length(){
                return  used;
            }
            public String[] get_araay(){
                return data;
            }
        }
        private  Context context;
        public CSVReader(Context context){
            this.context=context;
        }
        public List read(File file){
            List resultList = new ArrayList();
            try{
                InputStream inputStream= new FileInputStream(file);
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
                String csvLine;
                final char Separator = ',';
                final char Delimiter = '"';
                final char LF = '\n';
                final char CR = '\r';
                boolean quote_open = false;
                while ((csvLine = reader.readLine()) != null) {
                    //String[] row = csvLine.split(",");// simple way
                    StringDArray a=new StringDArray();
                    String token="";
                        csvLine+=Separator;
                    for(char c:csvLine.toCharArray()){
                        switch (c){
                            case LF: case CR:// not required as we are already read line
                                quote_open=false;
                                a.add(token);
                                token="";
                            break;
                            case Delimiter:
                                quote_open=!quote_open;
                            break;
                            case Separator:
                                if(quote_open==false){
                                    a.add(token);
                                    token="";
                                }else{
                                    token+=c;
                                }
                            break;
                            default:
                                token+=c;
                            break;
                        }
                    }
                    if(a.length()>0 ) {
                        if(resultList.size()>0){
                            String[] header_row =(String[]) resultList.get(0);
                            if(a.length()>=header_row.length) {
                                String[] row = a.get_araay();
                                resultList.add(row);
                            }
                        }else{
                            String[] row = a.get_araay();
                            resultList.add(row);//header row
                        }
                    }
                }
                inputStream.close();
            }catch (Exception e){
                Toast.makeText(context,"Error : " + e.getMessage(), Toast.LENGTH_LONG).show();
            }
            return resultList;
        }
    }

Usage

    File file=new File(path);
    CSVReader csvReader=new CSVReader(activity.this);
    List csv=csvReader.read(file);
    if(csv.size()>0){
        String[] header_row =(String[]) csv.get(0);
        if(header_row.length>1){
            String col1=header_row[0];
            String col2=header_row[1];
        }
    }

    Toast.makeText(activity.this,csv.size() + " rows", Toast.LENGTH_LONG).show();

Sample data used
ID,Name
1,Test Item 1
"2","Test Item 2"
"3","Test , Item 3"
4,Test Item 4

Answer 3

Android by default does not create the raw folder.Create a raw folder under res/raw in your project. copy your CSV File in that. keep the name of the CSV file lower case and convert into text format when asked. my CSV file name is welldata.scv WellData - it is the model class with getter and setter. 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) {
       //set splitter
        String[] tokens = line.split(",");

        //read the data
        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();
}

} }

Answer 4

Where to put the CSV file in Android Create a folder named “raw” inside the “res” folder and put the CSV file in it.

How to read CSV file, Nothing special since its Android. All we are going to use our standard Java code. Its better to use our own code instead of going to an API. Following class is an utility to read CSV file and it can be used from within the Android application. In which array we will store items of csv file In these example it is scorelist arraylist .

public class CSVFile {
    InputStream inputStream;

    public CSVFile(InputStream inputStream){
        this.inputStream = inputStream;
    }

    public List read(){
        List resultList = new ArrayList();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        try {
            String csvLine;
            while ((csvLine = reader.readLine()) != null) {
                String[] row = csvLine.split(",");
                resultList.add(row);
            }
        }
        catch (IOException ex) {
            throw new RuntimeException("Error in reading CSV file: "+ex);
        }
        finally {
            try {
                inputStream.close();
            }
            catch (IOException e) {
                throw new RuntimeException("Error while closing input stream: "+e);
            }
        }
        return resultList;
    }
}

So how to load the CSV file from “raw” folder and use the above utility to read it?

InputStream inputStream = getResources().openRawResource(R.raw.stats);
CSVFile csvFile = new CSVFile(inputStream);
List scoreList = csvFile.read();

MainActivity.java

public class MainActivity extends Activity {
    private ListView listView;
    private ItemArrayAdapter itemArrayAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView) findViewById(R.id.listView);
        itemArrayAdapter = new ItemArrayAdapter(getApplicationContext(), R.layout.item_layout);

        Parcelable state = listView.onSaveInstanceState();
        listView.setAdapter(itemArrayAdapter);
        listView.onRestoreInstanceState(state);

        InputStream inputStream = getResources().openRawResource(R.raw.stats);
        CSVFile csvFile = new CSVFile(inputStream);
        List scoreList = csvFile.read();

        for(String[] scoreData:scoreList ) {
            itemArrayAdapter.add(scoreData);
        }
    }
}

ItemArrayAdapter.java

public class ItemArrayAdapter extends ArrayAdapter {
    private List scoreList = new ArrayList();

    static class ItemViewHolder {
        TextView name;
        TextView score;
    }

    public ItemArrayAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    @Override
    public void add(String[] object) {
        scoreList.add(object);
        super.add(object);
    }

    @Override
    public int getCount() {
        return this.scoreList.size();
    }

    @Override
    public String[] getItem(int index) {
        return this.scoreList.get(index);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        ItemViewHolder viewHolder;
        if (row == null) {
            LayoutInflater inflater = (LayoutInflater) this.getContext().
                    getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = inflater.inflate(R.layout.item_layout, parent, false);
            viewHolder = new ItemViewHolder();
            viewHolder.name = (TextView) row.findViewById(R.id.name);
            viewHolder.score = (TextView) row.findViewById(R.id.score);
            row.setTag(viewHolder);
        } else {
            viewHolder = (ItemViewHolder)row.getTag();
        }
        String[] stat = getItem(position);
        viewHolder.name.setText(stat[0]);
        viewHolder.score.setText(stat[1]);
        return row;
    }
}

activity_mail.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.javapapers.android.csvfileread.app.MainActivity">
    <ListView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/listView"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp" />
</RelativeLayout>

item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/name"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="20dp" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/score"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_marginRight="20dp" />
</RelativeLayout>

For the whole source code you can refers to these link javapapers.com/wp-content/uploads/2014/07/CSVFileRead.zip

I think it will help

Answer 5

Disclaimer: I've never worked with Android, but I do know Java, so hopefully it's all the same.

That being said, you can try something like this.

Scanner scanner = new Scanner(new File("file.csv"));
ArrayList<String> pokemon = new ArrayList<>();
while(scanner.hasNextLine()) {
    pokemon.add(scanner.nextLine().split(",")[1]);
}
scanner.close();