index slow for big project

[zaiqiang-dong]

i use jdtls in nvim by nvim-jdtls, in aosp source ,there is many java file. the file index is very slow

it there a way to accelerate execution index?

[rgrunber]

If 21% is 85762 (the progress bar data tends to overestimate), then is the total number of index files truly in the hundreds of thousands ? That is a lot of dependencies. Are you able to share a sample of your project ? Or at least confirm it has a lot of dependencies ? You might be able to check by finding a folder in your workspace that has a path like .metadata/.plugins/org.eclipse.jdt.core . You'd want to count all the .index files in there.

I've been thinking if there's a way to improve this operation. Currently the only improvement we offer is within { "java": {"jdt": {"ls": {"vmargs": "...."}}}}. You can add a system property

-Djdt.core.sharedIndexLocation=${sharedIndexLocation}

where ${sharedIndexLocation} is a path to some folder on your system (Ideally something like /home/user/.cache/.jdt/index). The idea here is that projects can consult this location for the index of certain libraries, so if you've index the same library before, it won't need to be indexed again.

[zaiqiang-dong]

If 21% is 85762 (the progress bar data tends to overestimate), then is the total number of index files truly in the hundreds of thousands ? That is a lot of dependencies. Are you able to share a sample of your project ? Or at least confirm it has a lot of dependencies ? You might be able to check by finding a folder in your workspace that has a path like .metadata/.plugins/org.eclipse.jdt.core . You'd want to count all the .index files in there.

I've been thinking if there's a way to improve this operation. Currently the only improvement we offer is within { "java": {"jdt": {"ls": {"vmargs": "...."}}}}. You can add a system property

-Djdt.core.sharedIndexLocation=${sharedIndexLocation}

where ${sharedIndexLocation} is a path to some folder on your system (Ideally something like /home/user/.cache/.jdt/index). The idea here is that projects can consult this location for the index of certain libraries, so if you've index the same library before, it won't need to be indexed again.

Yes, it does contain a large number of Java files because I included the entire Android system's Java codebase. While I could remove unused dependencies, doing so would require frequent manual modifications to .classpath and .project files. My hardware is robust (Intel i9 13900 CPU and 64GB DDR5 RAM), yet the indexing process only utilizes around 5% of total CPU capacity. Is there a configuration method to improve indexing speed by allocating more CPU and memory resources?

Additionally, the entire source code includes some auto-generated files provided in .class format. Does the indexing process include these .class files? Furthermore, even though I configured a decompiler, why am I still unable to navigate to a decompiled .java file after indexing completes? Could there be a misconfiguration in the decompiler setup, or does the indexing system ignore .class files by default?

[rgrunber]

If the .class files are part of the classpath then yes they should be included the same as any jar file. What kind of project is it. Maven, Gradle, or are you using a custom .classpath to get this working ? Also, I would verify you're sending classFileContentsSupport: true in the extendedClientCapabilities of your initialize request to JDT-LS (some plugins for JDT-LS do set it up).

[zaiqiang-dong]

If the .class files are part of the classpath then yes they should be included the same as any jar file. What kind of project is it. Maven, Gradle, or are you using a custom .classpath to get this working ? Also, I would verify you're sending classFileContentsSupport: true in the extendedClientCapabilities of your initialize request to JDT-LS (some plugins for JDT-LS do set it up).

I test it in a maven project .
jdtls config as bellow:

local bdles = {}
vim.list_extend(
	bdles,
	vim.split(vim.fn.glob("~/.local/share/nvim/mason/packages/vscode-java-decompiler/server/*.jar"), "\n")
)

-- bdles is :
-- /home/zaiqdong/.local/share/nvim/mason/packages/vscode-java-decompiler/server/dg.jdt.ls.decompiler.cfr-0.0.3.jar
-- /home/zaiqdong/.local/share/nvim/mason/packages/vscode-java-decompiler/server/dg.jdt.ls.decompiler.common-0.0.3.jar
-- /home/zaiqdong/.local/share/nvim/mason/packages/vscode-java-decompiler/server/dg.jdt.ls.decompiler.fernflower-0.0.3.jar
-- /home/zaiqdong/.local/share/nvim/mason/packages/vscode-java-decompiler/server/dg.jdt.ls.decompiler.procyon-0.0.3.jar
-- vim.notify(bdles[1], vim.log.levels.INFO)

require("lspconfig").jdtls.setup({
	on_attach = on_attach,
	root_dir = vim.fs.root(0, { ".classpath", "pom.xml", "mvnw", "gradlew" }),
	settings = {
		java = {
			autobuild = {
				enabled = false,
			},
			import = { -- <- this
				maven = {
					enabled = true,
				},
				gradle = {
					enabled = true,
					wrapper = {
						enabled = true,
					},
				},
			},
			contentProvider = {
				preferred = "fernflower",
			},
		},
	},
	init_options = {
		bundles = bdles,
		extendedClientCapabilities = {
			classFileContentsSupport = true,
		},
	},
})

my pom.xm is :

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.zaiqiang</groupId>
  <artifactId>StartJava</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>StartJava</name>
  <url>http://maven.apache.org</url>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>21</maven.compiler.source>
    <maven.compiler.target>21</maven.compiler.target>
  </properties>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
    <dependency>
      <groupId>com.google.code.gson</groupId>
      <artifactId>gson</artifactId>
      <version>2.12.1</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>
</project>

but can not goto the class file or gson.java file of gson lib. Only goto a null file of gson.class, like:

Screencast.2025-04-01.11.24.44.mp4