Eclipse JDT Language Server (Modified)

This is a modified Eclipse JDT Language Server that only produces suggestions when it is confident that continuing the current valid program with one of the suggestions will result in a valid program.

What are changed?

Briefly speaking, a new language server request newCompletion is implemented that will return a null list when it cannot determine if any completion will yield a valid program. The detailed changes are listed here.

Installation from source

Clone the repository via git clone and build the project via JAVA_HOME=/path/to/java/11 ./mvnw clean verify -DskipTests=true to by-pass the tests. This command builds the server into the ./org.eclipse.jdt.ls.product/target/repository folder.

Running from the command line

cd into ./org.eclipse.jdt.ls.product/target/repository.

To start the server in the active terminal, adjust the following command as described further below and run it:

java \
	-Declipse.application=org.eclipse.jdt.ls.core.id1 \
	-Dosgi.bundles.defaultStartLevel=4 \
	-Declipse.product=org.eclipse.jdt.ls.core.product \
	-Dlog.level=ALL \
	-noverify \
	-Xmx1G \
	--add-modules=ALL-SYSTEM \
	--add-opens java.base/java.util=ALL-UNNAMED \
	--add-opens java.base/java.lang=ALL-UNNAMED \
	-jar ./plugins/org.eclipse.equinox.launcher_1.5.200.v20180922-1751.jar \
	-configuration ./config_linux \
	-data /path/to/data

1. Choose a value for -configuration: this is the path to your platform's configuration directory. For Linux, use ./config_linux. For windows, use ./config_win. For mac/OS X, use ./config_mac.
2. Change the filename of the jar in -jar ./plugins/... to match the version you built or downloaded.
3. Choose a value for -data: An absolute path to your data directory. eclipse.jdt.ls stores workspace specific information in it. This should be unique per workspace/project.

If you want to debug eclipse.jdt.ls itself, add -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=1044 right after java and ensure nothing else is running on port 1044. If you want to debug from the start of execution, change suspend=n to suspend=y so the JVM will wait for your debugger prior to starting the server.

License

EPL 2.0, See LICENSE file.