Upgrade to Eclipse 2021-09

[philwebb]

No description provided.

[quaff]

Eager for this, It block me using spring-javaformat.

[wilkinsona]

Let's just jump straight to 2021-09 which has built-in support for Java 17.

[wilkinsona]

As part of this, we need to revisit the fix for #262 as the System.getProperty call is now done in a lambda rather than an anonymous insert class.

[wilkinsona]

I have a local build that works with 2021-09. Unfortunately, 2021-09 contains a regression that causes 4 erroneous compilation failures in Spring Boot's buildpack platform module due to a method reference referring to an overloaded method. We may just have to live with those for now. Alternatively, changing the method references to lambda expressions appeases JDT's compiler.

[wilkinsona]

This upgrade is going to be problematic. The version of Eclipse JDT in 2021-09 has Java 11 class files (class file version 55) so projects with a Java 8 baseline will have to jump through some hoops to continue to use newer versions of the formatter. I'm not sure how it'll work at all in Maven, and in Gradle it would require us to rely on Toolchain support and Java 8 CI would require a Java 11 VM to be available as well.

[wilkinsona]

2021-09 makes some changes to the wrapping of annotation attributes. The following two diffs are from running format against Spring Boot's main branch:

-@SpringBootTest(properties = "spring.main.web-application-type=reactive", classes = {
-               WebTestClientSpringBootTestIntegrationTests.TestConfiguration.class, ExampleWebFluxApplication.class })
+@SpringBootTest(properties = "spring.main.web-application-type=reactive",
+               classes = { WebTestClientSpringBootTestIntegrationTests.TestConfiguration.class,
+                               ExampleWebFluxApplication.class })

-@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, properties = { "spring.jersey.type=filter",
-               "server.servlet.context-path=/app", "server.servlet.register-default-servlet=true" })
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT,
+               properties = { "spring.jersey.type=filter", "server.servlet.context-path=/app",
+                               "server.servlet.register-default-servlet=true" })

[wilkinsona]

I was mistaken above. Java 17 support isn't built into 2021-09, but is available as an add-on from the Marketplace. The add-on requires 2021-09.

JDT in 2021-06 has Java 8-level class files so it avoids some of the complications of 2021-09, but doesn't give us access to Java 17 support.

[wilkinsona]

A version built against 2021-06 seems to work fine in 2021-09 so that seems like a better short-term bet. I've opened #286 for that. I think we should revert the 2021-09 upgrade for now.

[philwebb]

I attempted to force a bytecode downgrade using cglib. It didn't go well. I think we'll need to branch the code and have a java 11 specific release.