[THRIFT-1909] Java: Add compiler flag to use the "option pattern" for optional fields

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.9.3
• Component/s: Java - Compiler, Java - Library
• Patch Info: Patch Available
• Assignee: Roger Meier
• Reporter: Eirik Sletteberg
• Created: 29/Mar/13 13:43
• Updated: 21/Jul/15 02:21
• Resolved: 23/Mar/15 19:43

Description

This is a follow-up of the brainstorming issue about better null safety in Java.

The patch adds:
1) A new abstract Option<T> class, with two subclasses: Some<T> and None<T>.
2) An optional compiler flag for the java compiler. When set, it wraps methods for optional fields in Option types.

An example of usage is found here: https://github.com/eirslett/thrift-optional-example

• No java dependencies are introduced.
• The patch is entirely backwards-compatible; if the compiler flag is not present, it will generate the same code as thrift usually does.
• The implementation is compatible with thrift servers/clients where the compiler flag is not used.

Issue Links

• is related to: THRIFT-1871 Better null-safe handling