# AWS Lambda Java Events SDK Transformer Library

### About

Provides helper classes/methods to use alongside `aws-lambda-java-events` in order to transform Lambda input event model
 objects into SDK-compatible output model objects 
 (eg. DynamodbEvent to a List of records writable back to DynamoDB through the AWS DynamoDB SDK for Java v1 or v2).
 

### Getting started

Add the following Apache Maven dependencies to your `pom.xml` file:

```xml
<dependencies>
    <dependency>
        <groupId>com.amazonaws</groupId>
        <artifactId>aws-lambda-java-events-sdk-transformer</artifactId>
        <version>3.1.0</version>
    </dependency>
    <dependency>
        <groupId>com.amazonaws</groupId>
        <artifactId>aws-lambda-java-events</artifactId>
        <version>3.11.2</version>
    </dependency>
</dependencies>
```

To use this library as a transformer to the AWS DynamoDB Java SDK v2, also add the following dependency to your `pom.xml` file:

```xml
<dependencies>
    <dependency>
        <groupId>software.amazon.awssdk</groupId>
        <artifactId>dynamodb</artifactId>
        <version>2.15.40</version>
    </dependency>
</dependencies>
```

To use this library as a transformer to the AWS DynamoDB Java SDK v1, add the following dependency to your `pom.xml` file instead:

```xml
<dependencies>
    <dependency>
        <groupId>com.amazonaws</groupId>
        <artifactId>aws-java-sdk-dynamodb</artifactId>
        <version>1.11.914</version>
    </dependency>
</dependencies>
```


### Example Usage

#### SDK v2

To convert a full `DynamodbEvent` object to an SDK v2 compatible `List<Record>`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v2.DynamodbEventTransformer;

public class DDBEventProcessor implements RequestHandler<DynamodbEvent, String> {

 public String handleRequest(DynamodbEvent ddbEvent, Context context) {
  // Process input event
  List<Record> convertedRecords = DynamodbEventTransformer.toRecordsV2(ddbEvent);
  // Modify records as needed and write back to DynamoDB using the DynamoDB AWS SDK for Java 2.0
 }
}
```

To convert a single `DynamodbEvent.DynamodbStreamRecord` object to an SDK v2 compatible `Record`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v2.dynamodb.DynamodbRecordTransformer;

public class MyClass {

 public void myMethod(DynamodbEvent.DynamodbStreamRecord record) {
  // ...
  Record convertedRecord = DynamodbRecordTransformer.toRecordV2(record);
  // ...
 }
}
```

To convert a `StreamRecord` object originating from a `DynamodbEvent` to an SDK v2 compatible `StreamRecord`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v2.dynamodb.DynamodbStreamRecordTransformer;

public class MyClass {

 public void myMethod(StreamRecord streamRecord) {
  // ...
  software.amazon.awssdk.services.dynamodb.model.StreamRecord convertedStreamRecord =
          DynamodbStreamRecordTransformer.toStreamRecordV2(streamRecord);
  // ...
 }
}
```

To convert an `AttributeValue` object originating from a `DynamodbEvent` to an SDK v2 compatible `AttributeValue`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v2.dynamodb.DynamodbAttributeValueTransformer;

public class MyClass {

 public void myMethod(AttributeValue attributeValue) {
  // ...
  software.amazon.awssdk.services.dynamodb.model.AttributeValue convertedAttributeValue =
          DynamodbAttributeValueTransformer.toAttributeValueV2(attributeValue);
  // ...
 }
}
```

To convert an `Identity` object originating from a `DynamodbEvent` to an SDK v2 compatible `Identity`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v2.dynamodb.DynamodbIdentityTransformer;

public class MyClass {

 public void myMethod(Identity identity) {
  // ...
  software.amazon.awssdk.services.dynamodb.model.Identity convertedIdentity =
          DynamodbIdentityTransformer.toIdentityV2(identity);
  // ...
 }
}
```

#### SDK v1

To convert a full `DynamodbEvent` object to an SDK v1 compatible `List<Record>`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v1.DynamodbEventTransformer;

public class DDBEventProcessor implements RequestHandler<DynamodbEvent, String> {

 public String handleRequest(DynamodbEvent ddbEvent, Context context) {
  // Process input event
  List<Record> convertedRecords = DynamodbEventTransformer.toRecordsV1(ddbEvent);
  // Modify records as needed and write back to DynamoDB using the DynamoDB AWS SDK for Java 2.0
 }
}
```

To convert a single `DynamodbEvent.DynamodbStreamRecord` object to an SDK v1 compatible `Record`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v1.dynamodb.DynamodbRecordTransformer;

public class MyClass {

 public void myMethod(DynamodbEvent.DynamodbStreamRecord record) {
  // ...
  Record convertedRecord = DynamodbRecordTransformer.toRecordV1(record);
  // ...
 }
}
```

To convert a `StreamRecord` object originating from a `DynamodbEvent` to an SDK v1 compatible `StreamRecord`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v1.dynamodb.DynamodbStreamRecordTransformer;

public class MyClass {

 public void myMethod(StreamRecord streamRecord) {
  // ...
  com.amazonaws.services.dynamodbv2.model.StreamRecord convertedStreamRecord =
          DynamodbStreamRecordTransformer.toStreamRecordV1(streamRecord);
  // ...
 }
}
```

To convert an `AttributeValue` object originating from a `DynamodbEvent` to an SDK v1 compatible `AttributeValue`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v1.dynamodb.DynamodbAttributeValueTransformer;

public class MyClass {

 public void myMethod(AttributeValue attributeValue) {
  // ...
  com.amazonaws.services.dynamodbv2.model.AttributeValue convertedAttributeValue =
          DynamodbAttributeValueTransformer.toAttributeValueV1(attributeValue);
  // ...
 }
}
```

To convert an `Identity` object originating from a `DynamodbEvent` to an SDK v1 compatible `Identity`:

```java
import com.amazonaws.services.lambda.runtime.events.transformers.v1.dynamodb.DynamodbIdentityTransformer;

public class MyClass {

 public void myMethod(Identity identity) {
  // ...
  com.amazonaws.services.dynamodbv2.model.Identity convertedIdentity =
          DynamodbIdentityTransformer.toIdentityV1(identity);
  // ...
 }
}
```