How do I format EditText for currency input in Android?

The following Android code snippet shows you how to customize the input value format of an EditText component for accepting currency number. To format the input value we will create a text watcher class called MoneyTextWatcher, this class implements of the android.text.TextWatcher interface.

In the MoneyTextWatcher class we implement the afterTextChanged(EditText s) method, in this method the currency formatting takes place by adding currency symbol before the digit on numbers.

To apply this text watcher class we call the addTextChangedListener() method of the EditText object of the currency input and pass an instance of MoneyTextWatcher. Below is the working example of the activity class and the text watcher.

package org.kodejava.android;

import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;

import java.math.BigDecimal;

public class MainActivity extends AppCompatActivity {
    private EditText editText;
    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editText = findViewById(R.id.editText);
        editText.addTextChangedListener(new MoneyTextWatcher(editText));
        editText.setText("0");

        textView = findViewById(R.id.textView);
    }

    public void doGetValue(View view) {
        BigDecimal value = MoneyTextWatcher.parseCurrencyValue(editText.getText().toString());
        textView.setText(String.valueOf(value));
    }
}

When the EditText input is changed the afterTextChanged() method of the text watcher will be called. In this method we’ll take the input text and format the input value with currency symbol and a number, this is done by the NumberFormat.getCurrencyInstance() object.

The static helper method parseCurrencyValue() will get the number part of the EditText by removing the currency symbol and return the input number.

package org.kodejava.android;

import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.widget.EditText;

import java.lang.ref.WeakReference;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Objects;

public class MoneyTextWatcher implements TextWatcher {
    private static final Locale locale = new Locale("id", "ID");
    private static final DecimalFormat formatter = (DecimalFormat) NumberFormat.getCurrencyInstance(locale);
    private final WeakReference<EditText> editTextWeakReference;

    public MoneyTextWatcher(EditText editText) {
        editTextWeakReference = new WeakReference<>(editText);
        formatter.setMaximumFractionDigits(0);
        formatter.setRoundingMode(RoundingMode.FLOOR);

        DecimalFormatSymbols symbol = new DecimalFormatSymbols(locale);
        symbol.setCurrencySymbol(symbol.getCurrencySymbol() + " ");
        formatter.setDecimalFormatSymbols(symbol);
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }

    @Override
    public void afterTextChanged(Editable s) {
        EditText editText = editTextWeakReference.get();
        if (editText == null || editText.getText().toString().isEmpty()) {
            return;
        }
        editText.removeTextChangedListener(this);

        BigDecimal parsed = parseCurrencyValue(editText.getText().toString());
        String formatted = formatter.format(parsed);

        editText.setText(formatted);
        editText.setSelection(formatted.length());
        editText.addTextChangedListener(this);
    }

    public static BigDecimal parseCurrencyValue(String value) {
        try {
            String replaceRegex = String.format("[%s,.\\s]",
                    Objects.requireNonNull(formatter.getCurrency()).getSymbol(locale));
            String currencyValue = value.replaceAll(replaceRegex, "");
            currencyValue = "".equals(currencyValue) ? "0" : currencyValue;
            return new BigDecimal(currencyValue);
        } catch (Exception e) {
            Log.e("App", e.getMessage(), e);
        }
        return BigDecimal.ZERO;
    }
}

The following animation is the result of our code snippet above, and you can find to complete source code here: Android Currency EditText Example