---
title: "Handle and extract data from Callbacks"
url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-and-extract-data-from-callbacks-jni"
source_url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-and-extract-data-from-callbacks-jni.md"
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last_modified: "2026-05-23T12:56:20+02:00"
language: "en"
---

# Handle and extract data from Callbacks

[View source](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-and-extract-data-from-callbacks-jni.md)

## Variable

| Name            | Description                                                                                                                                                                                                                                                                                                                       |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `LibraryResult` | Use in-app declared variables to extract and store data. Initialize variables on the cash register side and pass them as arguments to the methods provided by the Java Native Interface (JNI). The JNI then assigns the appropriate value to the variables. The cash register can then access, store and process the information. |

The following pages describe extracting data from callbacks:

[Handle progress events - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-progress-events-jni)

[Handle Dynamic Currency Conversion - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/extras-jni/handle-dynamic-currency-conversion-jni)

[Display a screen on a large screen terminal - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/extras-jni/display-a-screen-on-a-large-screen-terminal-jni)

[Handle the Signature callback - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-the-signature-callback-jni)

[Handle the Print Receipt callback - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-the-print-receipt-callback-jni)

[Handle the PED Exception Callback - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/extras-jni/handle-the-ped-exception-callback-jni)

[Handle the Additional Data callback - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-the-additional-data-callback-jni)