Design: Convention, Status: Accepted

Use of Optional

This page describes a general guideline for the use of java.util.Optional in the AWS SDK for Java 2.x.

• Optional MUST NOT be used under any circumstances when the result will never be null.
• For return types,
  • Optional SHOULD be used when it is not obvious to a caller whether a result will be null, e.g, public <T> Optional<T> getValueForField(String fieldName, Class<T> clazz)in SdkResponse.java
  • Optional MUST NOT be used for “getters” in generated service model classes such as service Builders or POJOs.
• For member variables: Optional SHOULD NOT be used, e.g., private final Optional<String> field;
• For method parameters: Optional MUST NOT be used, e.g., private void test(Optional<String> value)

References:

• http://blog.joda.org/2015/08/java-se-8-optional-pragmatic-approach.html