1*8a52c783SCole Faust**Design:** Convention, **Status:** [Accepted](README.md) 2*8a52c783SCole Faust 3*8a52c783SCole Faust## Use of Optional 4*8a52c783SCole Faust 5*8a52c783SCole FaustThis page describes a general guideline for the use of 6*8a52c783SCole Faust`java.util.Optional` in the AWS SDK for Java 2.x. 7*8a52c783SCole Faust 8*8a52c783SCole Faust- `Optional` MUST NOT be used under any circumstances when the result will never be null. 9*8a52c783SCole Faust- For return types, 10*8a52c783SCole Faust - `Optional` SHOULD be used when it is not obvious to a caller whether a 11*8a52c783SCole Faust result will be null, e.g, `public <T> Optional<T> getValueForField(String fieldName, Class<T> clazz)`in [SdkResponse.java](https://github.com/aws/aws-sdk-java-v2/blob/aa161c564c580ced4a0381d3ed7d4d13120916fc/core/sdk-core/src/main/java/software/amazon/awssdk/core/SdkResponse.java#L59-L61) 12*8a52c783SCole Faust - `Optional` MUST NOT be used for "getters" in generated service model classes such as service Builders or POJOs. 13*8a52c783SCole Faust- For member variables: `Optional` SHOULD NOT be used, e.g., `private final Optional<String> field;` 14*8a52c783SCole Faust- For method parameters: `Optional` MUST NOT be used, e.g., `private void test(Optional<String> value)` 15*8a52c783SCole Faust 16*8a52c783SCole Faust 17*8a52c783SCole FaustReferences: 18*8a52c783SCole Faust 19*8a52c783SCole Faust- http://blog.joda.org/2015/08/java-se-8-optional-pragmatic-approach.html 20