> For the complete documentation index, see [llms.txt](https://docs.payments.thalescloud.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payments.thalescloud.io/nfc-wallet-sdk-android/implement-nfc-wallet/make-payment/implement-contactless-payments/6.-display-transaction-context.md).

# 6. Display transaction context

## Overview

After each transaction, your **digital wallet application** can display transaction details.

NFC Wallet SDK provides a `TransactionContext` in these callbacks:

* `ContactlessPaymentServiceListener.onTransactionCompleted()`
* `ContactlessPaymentServiceListener.onError()`

{% hint style="warning" %}
Treat `TransactionContext` as sensitive data.

Call `TransactionContext.wipe()` after you finish using it.
{% endhint %}

## SDK integration

### Read and format transaction details

Read the values you need from the context, then format them for display.

{% code title="MyPaymentListener.java" expandable="true" %}

```java
@Override
public void onTransactionCompleted(TransactionContext ctx) {
    try {
        TransactionData data = TransactionData.from(ctx);
        // Display data in your UI.
    } finally {
        ctx.wipe();
    }
}

@Override
public void onError(
        TransactionContext ctx,
        PaymentServiceErrorCode errorCode,
        String message) {

    if (ctx == null) {
        // Handle the error when no transaction context is available.
        return;
    }

    try {
        TransactionData data = TransactionData.from(ctx);
        // Display data and error details in your UI.
    } finally {
        ctx.wipe();
    }
}

/**
 * Convenience data class for transaction display.
 */
public class TransactionData {

    private final String currencyCode;
    private final double amount;
    private final String transactionDate;
    private final String transactionType;
    private final String transactionId;

    private TransactionData(
            String currencyCode,
            double amount,
            String transactionDate,
            String transactionType,
            String transactionId) {
        this.currencyCode = currencyCode;
        this.amount = amount;
        this.transactionDate = transactionDate;
        this.transactionType = transactionType;
        this.transactionId = transactionId;
    }

    public static TransactionData from(TransactionContext ctx) {
        String currencyCode = TransactionDisplayUtils.bcdToString(ctx.getCurrencyCode());
        String transactionDate = TransactionDisplayUtils.bcdToString(ctx.getTrxDate());
        String transactionType = TransactionDisplayUtils.getTransactionType(ctx.getTrxType());

        return new TransactionData(
                currencyCode,
                ctx.getAmount(),
                transactionDate,
                transactionType,
                ctx.getTrxId());
    }

    public String getCurrencyCode() {
        return currencyCode;
    }

    public double getAmount() {
        return amount;
    }

    public String getTransactionDate() {
        return transactionDate;
    }

    public String getTransactionType() {
        return transactionType;
    }

    public String getTransactionId() {
        return transactionId;
    }
}
```

{% endcode %}

### Convert BCD values for display (utility)

The following utility converts BCD-encoded values to strings.

Adjust the formatting to match your UI and your payment network requirements.

{% code title="TransactionDisplayUtils.java" expandable="true" %}

```java
public final class TransactionDisplayUtils {

    private TransactionDisplayUtils() {
        // Utility class.
    }

    public static String bcdToString(byte[] bcd) {
        if (bcd == null) {
            return "";
        }

        StringBuilder sb = new StringBuilder();
        for (byte b : bcd) {
            sb.append(bcdToString(b));
        }
        return sb.toString();
    }

    public static String bcdToString(byte bcd) {
        int high = (bcd & 0xF0) >>> 4;
        int low = (bcd & 0x0F);
        return String.valueOf(high) + low;
    }

    public static String getTransactionType(byte trxType) {
        switch (trxType) {
            case 0:
                return "PAY";
            case 32:
                return "REFUND";
            default:
                return "TRANSACTION";
        }
    }
}
```

{% endcode %}


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