java/api-changes.md

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# Arrow Java API Changes

This document tracks behavior changes to Java APIs, as listed below.

- **[ARROW-5973](https://issues.apache.org/jira/browse/ARROW-5973)**:
  * **Start date**: 2019/07/18
  * **Resolve date**: 2019/07/20
  * **Brief description**: The semantics of the get methods for [VarCharVector](./vector/scr/main/org/apache/arrow/vector/VarCharVector.java), [VarBinaryVector](./vector/scr/main/org/apache/arrow/vector/VarBinaryVector.java), and [FixedSizeBinaryVector](./vector/scr/main/org/apache/arrow/vector/FixedSizeBinaryVector.java) changes. In the past, if the validity bit is clear, the methods throw throws an IllegalStateException when NULL_CHECKING_ENABLED is set, or returns an empty object when the flag is not set. Now, the get methods return a null if the validity bit is clear.

- **[ARROW-5842](https://issues.apache.org/jira/browse/ARROW-5842)**:
  * **Start date**: 2019/07/04
  * **Resolve date**: 2019/07/11
  * **Brief description**: The semantics of lastSet member in class [ListVector](./vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java) changes. In the past, it refers to the next index that will be set. After the change it points to the last index that is actually set.