# Bank Transactions - Java SDK

One API for multiple online identity verification methods written in Java.

## Installation

The installation of the library is as simple as including it as one of the projects dependencies.

We encourage to use the newest version of the library as we are constantly expanding our product
offering and the underlying functionalities.

### Maven

Include the following dependency in your `pom.xml` file to use Authologic Java SDK:

```xml
<dependency>
    <groupId>com.authologic.client</groupId>
    <artifactId>authologic-client</artifactId>
    <version>0.2.42</version>
</dependency>
```

### Gradle

Include the following dependency in your `build.gradle` file to use Authologic Java SDK:

```java
implementation("com.authologic.client:authologic-client:0.2.42")
```

## Usage

The following example demonstrates how to use the Java SDK to interact with the Authologic APIs.

### Creating Conversation

To start a new conversation process, which is the main entry point for the identity checking product the
following example can be used:

```java
import com.authologic.client.api.*;

import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        Client client = ClientBuilder.builder("username", "password").sandbox().build();

        Conversation conversation = client.execute(
            Requests.
                createConversation().
                strategy("public:sandbox").
                callbackUrl("some_callback_url").
                addProduct(
                    new IdentityProductQueryBuilder(
                        Arrays.asList(
                            IdentityQueryField.PERSON_NAME_FIRSTNAME,
                            IdentityQueryField.PERSON_NAME_LASTNAME
                        )
                    )).
                addProduct(
                    new BankTransactionsProductQueryBuilder()
                )
        ).get();

        System.out.println(conversation.getUrl());
    }
}
```

#### Creating the Client Instance

We start by creating the Client instance:

```java
Client client = ClientBuilder.builder("username", "password").sandbox().build();
```

API credentials can be generated via OmniPanel.
Because the API is secured you need the provided credentials to be able to interact with it.
Once initialized the `Client` instance may be used to interact with the Authologic API.

#### Creating the Conversation

Next we can create the conversation and request the first and last name of the person we are
requesting the identification for. For that purpose we use the `Requests.createConversation()`
using the following code snippet:

```java
Requests.
    createConversation().
    strategy("public:sandbox").
    callbackUrl("some_callback_url").
    addProduct(
        new IdentityProductQueryBuilder(
            Arrays.asList(
                IdentityQueryField.PERSON_NAME_FIRSTNAME,
                IdentityQueryField.PERSON_NAME_LASTNAME
            )
        )
    ).
    addProduct(
        new BankTransactionsProductQueryBuilder()
    )
```

We set:

- the strategy
- the callback URL
- the products that we want to use.

The **strategy** is the information that tells Authologic how to perform the operation.
The field is optional, but you can explicitly provide the information to choose the strategy that
you want to use. In the above example we used the `public:sandbox`, a strategy which doesn't perform a
real verification, but allows to test the whole flow.

The **callback URL** is the URL that Authologic will send the user when the process, in our example case
the identification process, will be completed. You should set it to match return to your application or
use a service like [Webhook Site](https://webhook.site/) if you plan on testing the SDK.

The products that we want to use in this example are the [identity](/docs/../products/identity) product
and the [bank transactions](/docs/../products/bank-transactions) product.

For the `identity` product we use the `IdentityProductQueryBuilder` class and provide the list of
fields to retrieve:

```java
new IdentityProductQueryBuilder(
    Arrays.asList(
        IdentityQueryField.PERSON_NAME_FIRSTNAME,
        IdentityQueryField.PERSON_NAME_LASTNAME
    )
))
```

For the `bankTransactions` product we use the `BankTransactionsProductQueryBuilder` class:

```java
addProduct(
    new BankTransactionsProductQueryBuilder()
)
```

As the final step we print the URL of the created conversation to the standard output to be able to continue
the process. If you are trying out the SDK head to the returned link to fill out the data that will be
returned as test data for your identity verification test.

### Working with Callbacks

<note>

**Project dependencies:**
Please remember that when working with callbacks you not only need the
`authologic-client` library, but also `authologic-client-json` and one of the JSON parsing modules, for example
`authologic-client-module-jackson`.

</note>

The Java SDK can also be used to parse the information sent to your callback URL. It is as simple as initializing one
of the JSON parsing engines, deserializing the body of the request received in the callback and using the result data.
For example this is how the code could look like:

```java
JsonEngine jsonEngine = (new JacksonJsonEngineProvider()).createJsonEngine();
Callback callback = jsonEngine.deserialize(callbackBody, Callback.class);

if (callback.isConversationFinished()) {
    Conversation conversation = callback.asConversationFinished().getConversation();
    if (conversation.getResult().getBankTransactions().getStatus() == ProductResultStatus.FINISHED) {
        // TODO: schedule bank transactions fetching
    }
}
```

Let's discuss the above example.

#### Initializing JSON Parser

We start by initializing the JSON parser, so we can easily parse the response.
We do it only once as the parser is thread-safe and can be reused later when needed:

```java
JsonEngine jsonEngine = (new JacksonJsonEngineProvider()).createJsonEngine();
```

#### Deserializing the Results

We assume that we got the callback body and stored i tin the `callbackBody` variable. Once we have it
we can easily deserialize it to the `CallbackResult` class using the initialized JSON parser:

```java
Callback callbackResult = jsonEngine.deserialize(ctx.body(), Callback.class);
```

The abstract Callback class provides two methods to identify the type of the result:

- the `isConversationFinished` returning `true` if the result is of type `Conversation` representing conversation
- the `isUnknownCallback` returning `true` if the result is of type `UnknownCallback` representing unknown callback

In the example code we expect the `FinishedConversationCallback`, so we check for it:

```java
if (callback.isConversationFinished()) {
```

After we verified that we got the class we were expecting we can retrieve the conversation from the
deserialized object and check whether the bank transactions are ready and if they are, we can schedule
fetching of the bank transactions via the dedicated API:

```java
Conversation conversation = callback.asConversationFinished().getConversation();
if (conversation.getResult().getBankTransactions().getStatus() == ProductResultStatus.FINISHED) {
    // TODO: schedule bank transactions fetching
}
```