Comprehensive Servlet 3.1 support in spring-web and spring-test [SPR-14467]

[spring-projects-issues]

Rossen Stoyanchev opened SPR-14467 and commented

spring-web needs to compile with Servlet 3.1 to take advantage of the non-blocking I/O but we originally aimed to maintain 3.0 compatibility.

As a result of the reactive merge the ContentCachingRequest/ResponseWrapper had to implement 3.1 methods with Read/WriteListener. We'd need a custom solution that makes those usable with Servlet 3.0+.

Along the same lines the upgrade also required some test classes to add 3.1 related methods. Many of those were temporarily added without implementation, i.e. raising an exception. We should review and add implementations.

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Issue Links:

• Drop Servlet 2.5 runtime compatibility [SPR-13189] #17781 Drop Servlet 2.5 runtime compatibility
• Support for Servlet 4.0 API [SPR-12674] #17273 Support for Servlet 4.0 API

[spring-projects-issues]

Juergen Hoeller commented

It turns out that full support for Servlet 3.1 async streams in our filter implementations requires building and running against Servlet 3.1.

So while we had a vague Servlet 3.0 compromise baseline before, it seems feasible - or even necessary - to raise to Servlet 3.1+ as of Spring Framework 5.0 M1 already. This is consistent with our general EE 7 baseline (JPA 2.1, Bean Validation 1.1) anyway, just not tolerating mixed setups anymore for our 2017+ generation of the framework.