Subject: 29.1; Eglot jdtls formatter ignored

From: Cay Horstmann <[email-masked]>
Date: Tue, 24 Oct 2023 11:17:09 +0200

Eglot does not trigger a custom formatter with jdtls, while lsp-java and VS Code with the Red Hat Java plugin can do this. See https://github.com/joaotavora/eglot/discussions/1222 for more background.

I attach files
* eglot-debug.el (the minimal configuration to see the failure)
* NotHelloWorld.java (a sample Java file)
* cay-eclipse-formatter.xml (the formatting rules for jdtls)
* eglot-events.txt (the events log from eglot)
* lsp-java-debug.el (the minimal configuration to see how it works with lsp-java)
* lsp-log.txt (the log from the successful run with lsp)

Download jdtls from https://download.eclipse.org/jdtls/snapshots/?d. I
have the version from Oct. 14, 2023. Put it somewhere on your PATH

Put the NotHelloWorld.java file in some directory (I use /tmp/hello)

Put the cay-eclipse-formatter.xml file somewhere and adjust the path in eglot-debug.el and lsp-java-debug.el.

emacs -q -l eglot-debug.el /tmp/hello/NotHelloWorld.java

M-x eglot RET

Wait for jdtls to start

M-x eglot-format-buffer RET

The formatting should now use the rules in the cay-eclipse-formatter.xml
file, resulting in 8 changes but the same Allman indentation
style. Instead, it uses a K&R indentation style.

To see the proper formatting, install lsp-mode and lsp-java and start with lsp-java-debug.el. Or use VS Code with the Red Hat Java plugin and the settings.json

{
     "java.format.settings.url": "file:///data/cay/bin/cay-eclipse.formatter.xml",
     "java.format.settings.profile": "cay"
}

In GNU Emacs 29.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.33,
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Windowing system distributor 'The X.Org Foundation', version 11.0.12101004
System Description: Ubuntu 22.04.3 LTS

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Configured features:
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Load-path shadows:
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