> 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 %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.payments.thalescloud.io/nfc-wallet-sdk-android/implement-nfc-wallet/make-payment/implement-contactless-payments/6.-display-transaction-context.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.