> For the complete documentation index, see [llms.txt](https://onestore-dev.gitbook.io/dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://onestore-dev.gitbook.io/dev/eng/tools/billing/v21/references/classes/purchaseclient.builder.md).

# PurchaseClient.Builder

public static final class PurchaseClient.Builder\
java.lang.Object    ↳ com.gaa.sdk.iap.PurchaseClient.Builder

\
A builder that helps create a [PurchaseClient](/dev/eng/tools/billing/v21/references/classes/purchaseclient.md) instance easily.

\
Public Methods <a href="#id-en-purchaseclient.builder-publicmethods" id="id-en-purchaseclient.builder-publicmethods"></a>
-------------------------------------------------------------------------------------------------------------------------

***

### setBase64PublicKey <a href="#id-en-purchaseclient.builder-setbase64publickey" id="id-en-purchaseclient.builder-setbase64publickey"></a>

@UiThreadpublic PurchaseClient.Builder setBase64PublicKey(String base64PublicKey)\
Please specify the public key that is issued from the developer center to check the validity of purchase information.

| **Parameters:**        |                        |
| ---------------------- | ---------------------- |
| base64PublicKey        | base64EncodedPublicKey |
| **Returns**            |                        |
| PurchaseClient.Builder | <p><br></p>            |

### setListener <a href="#id-en-purchaseclient.builder-setlistener" id="id-en-purchaseclient.builder-setlistener"></a>

@UiThreadpublic PurchaseClient.Builder setListener(PurchasesUpdatedListener[ ](https://dev.onestore.co.kr/wiki/en/doc/en-purchasesupdatedlistener-38077521.html)listener)\
Please specify to receive onPurchasesUpdated event.

| **Parameters:**        |                                                                                                          |
| ---------------------- | -------------------------------------------------------------------------------------------------------- |
| listener               | [PurchasesUpdatedListener](/dev/eng/tools/billing/v21/references/interfaces/purchasesupdatedlistener.md) |
| **Returns:**           |                                                                                                          |
| PurchaseClient.Builder | <p><br></p>                                                                                              |

### build <a href="#id-en-purchaseclient.builder-build" id="id-en-purchaseclient.builder-build"></a>

@UiThreadpublic PurchaseClient[ ](https://dev.onestore.co.kr/wiki/en/doc/en-purchaseclient-38077503.html)build()\
Creates a PurchaseClient's instance.

| **Return:**                                                                       |                                                  |
| --------------------------------------------------------------------------------- | ------------------------------------------------ |
| [PurchaseClient](/dev/eng/tools/billing/v21/references/classes/purchaseclient.md) | <p><br></p>                                      |
| **Throws:**                                                                       |                                                  |
| java.lang.IllegalArgumentException                                                | Occurs if the context or listener is not normal. |