bug: No delegateCommandHandler for vscode.java.test.findTestTypesAndMethods

Did you check docs and existing issues?

I have read all the plugin docs
I have searched the existing issues
I have searched the existing issues of plugins related to this issue

Neovim version (nvim -v)

v0.10.1

Operating system/version

MacOS 14.4.1

Describe the bug

I have an installation of nvim-java as follows -

{
    "nvim-java/nvim-java",
    dependencies = {
      "neovim/nvim-lspconfig",
      'nvim-java/lua-async-await',
      'nvim-java/nvim-java-refactor',
      'nvim-java/nvim-java-core',
      'nvim-java/nvim-java-test',
      'nvim-java/nvim-java-dap',
      'MunifTanjim/nui.nvim',
      'neovim/nvim-lspconfig',
      'mfussenegger/nvim-dap',
      {
        'JavaHello/spring-boot.nvim',
        commit = '218c0c26c14d99feca778e4d13f5ec3e8b1b60f0',
      },
      {
        'williamboman/mason.nvim',
        opts = {
          registries = {
            'github:nvim-java/mason-registry',
            'github:mason-org/mason-registry',
          },
        },
      },
      opts = {
        servers = {
          jdtls = {
            settings = {
              java = {
                configuration = {
                  runtimes = {
                    {
                      name = "JavaSE-17",
                      path = "/opt/homebrew/opt/openjdk@17/bin/java",
                      default = true
                    },
                    {
                      name = "JavaSE-11",
                      path = "/opt/homebrew/opt/openjdk@11/bin/java",
                    }
                  }
                }
              },
            },
          },
        },
        setup = {
          jdtls = function()
            require("java").setup()
          end,
        },
      },
    },

When i attempt to run ANY java method provided by the plugin, I get the following error:

 02:25:21 msg_show.lua_error   JavaTestRunCurrentClass Error executing vim.schedule lua callback: ...site/pack/lazy/opt/nvim-java/lua/java/handlers/error.lua:28: 
failed to run the current test class
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.test.findTestTypesAndMethods"
stack traceback:
	...site/pack/lazy/opt/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
	...ck/lazy/opt/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:72: in function 'handler'
	.../neovim/0.10.1/share/nvim/runtime/lua/vim/lsp/client.lua:687: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>
stack traceback:
	[C]: in function 'error'
	...site/pack/lazy/opt/nvim-java/lua/java/handlers/error.lua:28: in function 'error_handler'
	...ck/lazy/opt/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:72: in function 'handler'
	.../neovim/0.10.1/share/nvim/runtime/lua/vim/lsp/client.lua:687: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>

I have checked and all the plugins have been successfully downloaded, as well as jdtls, java-test and java-debug-adapter.

Steps To Reproduce

Install v2.0.1 of nvim-java
Open java file and attempt to run any of the java commands

Expected Behavior

Expect to see error described in the bug report.

I have the same issue but, the error appears also immediately after the "Configuring DAP" message.

Neovim version (nvim -v)
v0.10.1

Operating system/version
Arch Linux

Same here

I am also getting the same issue

Any updates along these lines? I started seeing this error in the last 4-5 days.

Same

What are the versions of java-debug-adapter, java-test, jdtls you see in Mason?

Your config doesn't seem to be the latest. Please try following the latest guide which is much more simpler with latest Lazy.nvim.

You can now try nvim-java inside a container with docker & devcontainer, everything will be setup for you automatically:
https://github.com/nvim-java/play-lazyvim

There is also a starter project for LazyVim, Kickstart and AstroNvim here:
https://github.com/nvim-java/nvim-java?tab=readme-ov-file#starter-configs-recommend-for-newbies

~~I cloned Kickstart yesterday, applied the changes on these 3 commits and got the same error.~~

Update: The issue is inside ~/.local/share/nvim (my main config). I was using NVIM_APPNAME=jkickstart.nvim nvim for kickstart.nvim inside my ~/.config for testing, it creates ~/.local/share/jkickstar.nvim, but somehow it was being interfered from my main config.

I didn't find out the origin of the problem though

FWIW, I was seeing this error when I had the latest jdtls installed (1.41), upon adding github:nvim-java/mason-registry to mason registries it installed the ver.1.37 for me which fixed the issue.

I'm also getting similar issue, I can provide details:

Versions

Neovim version
v0.10.2

Operating system/version
MacOS Version 15.1

java-debug-adapter version
0.58.0

java-test version
0.40.1
note: this version seems to be locked, since everytime I try to update it will reinstall this exact version

jdtls version
v1.37.0

JDK version
openjdk version "17.0.12" 2024-07-16
OpenJDK Runtime Environment JBR-17.0.12+1-1087.25-jcef (build 17.0.12+1-b1087.25)
OpenJDK 64-Bit Server VM JBR-17.0.12+1-1087.25-jcef (build 17.0.12+1-b1087.25, mixed mode)

Setup

I use kickstart.nvim, with similar setup as above but simpler:

  {
    'nvim-java/nvim-java',
    config = function()
      require('java').setup {
        java_debug_adapter = {
          enable = false,
        },
      }
    end,
  },
  {
    'neovim/nvim-lspconfig',
    config = function()
      local servers = {
        jdtls = {},
      }

      require('mason').setup()

      local ensure_installed = vim.tbl_keys(servers or {})
      vim.list_extend(ensure_installed, {
        'stylua', -- Used to format lua code
      })
      require('mason-tool-installer').setup { ensure_installed = ensure_installed }

      require('mason-lspconfig').setup {
        handlers = {
          function(server_name)
            local server = servers[server_name] or {}
            server.capabilities = vim.tbl_deep_extend('force', {}, capabilities, server.capabilities or {})
            require('lspconfig')[server_name].setup(server)
          end,
        },
      }
    end
  }

I got this error on opening a java file, even though I already disabled the DAP

# result from :messages
Error executing vim.schedule lua callback: ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:28:
dap configuration failed
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.resolveMainClass"
stack traceback:
        ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
        ...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
        ...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:72: in function 'handler'
        ...eovim/0.10.2_1/share/nvim/runtime/lua/vim/lsp/client.lua:687: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>

Hope this clarifies.

@radon115

I get it too for both maven and gradle and new and existing projects.

dap configuration failed
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.resolveMainClass"
stack traceback:
^I...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
^I...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
^I...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:72: in function 'handler'
^I/usr/share/nvim/runtime/lua/vim/lsp/client.lua:687: in function ''
^Ivim/_editor.lua: in function <vim/_editor.lua:0>

edit:
~~After adding java mason registry as suggested by @radon115 error no longer appears.~~

Despite adding registry error reappeared and is constantly shown everytime i open mason / gradle project.

Simplest steps to reproduce:

gradle init (basic structure)
create src/main/java/com/example/app/MyApp.java
open .../MyApp.java
message appeared: Configuring DAP followed by dap configuration failed ...

Or open any existing project.

Tools outside nvim:
Arch Linux
Gradle 8.10.2
openjdk 21.0.5

Tools installed with nvim/ mason
NVIM v0.10.2
JDTLS v1.37.0
java-test 0.40.1
java-debug-adapter 0.58.0
lombok-nightly
openjdk-17
spring-boot-tools 1.55.1

edit2:
disabling dap doesn't work:

require('java').setup {
        java_debug_adapter = {
          enable = false,
        },
      }

edit3
uninstalling java-debug-adapter via Mason doesn't work either as it is installed nex time Neovim starts.

Can confirm that this issue still exists after updating to nvim-java 3.0.0. Here is my config.

Can you provide details about your system as provided in the post above yours please?

Versions

Neovim version

v0.11.3

Operating system/version

MacOS 14.7.1

java-debug-adapter version

0.58.2

java-test version

0.40.1

jdtls version

v1.43.0

JDK version

java 21.0.6 2025-01-21 LTS
Java(TM) SE Runtime Environment (build 21.0.6+8-LTS-188)
Java HotSpot(TM) 64-Bit Server VM (build 21.0.6+8-LTS-188, mixed mode, sharing)

Config

  {
    'nvim-java/nvim-java',
    lazy = true,
  },
  { -- LSP Configuration & Plugins
    'neovim/nvim-lspconfig',
    event = 'VeryLazy',
    dependencies = {
      { 'mason-org/mason.nvim', cmd = { 'Mason' }, opts = {} },
      { 'mason-org/mason-lspconfig.nvim', opts = {} },
      'WhoIsSethDaniel/mason-tool-installer.nvim',
    },
    config = function()
      ...

      require('java').setup {
        jdk = { auto_install = false },
      }
      require('lspconfig').jdtls.setup {
        {
          handlers = {
            -- By assigning an empty function, you can remove the notifications
            -- printed to the cmd
            ['$/progress'] = function(_, result, ctx) end,
          },
        },
      }

      for server_name, config in pairs(servers) do
        local excluded_servers = { 'tailwindcss' }

        local function contains(excluded, server)
          for _, v in ipairs(excluded) do
            if v == server then
              return true
            end
          end
          return false
        end

        if contains(excluded_servers, server_name) then
          goto continue
        end
        vim.lsp.config(server_name, config)
        ::continue::
      end
    end,
  },

Error

Error executing vim.schedule lua callback: ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:28: 
dap configuration failed
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.resolveMainClass"
stack traceback:
	...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
	...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:74: in function 'handler'
	.../neovim/0.11.3/share/nvim/runtime/lua/vim/lsp/client.lua:682: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>
stack traceback:
	[C]: in function 'error'
	...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:28: in function 'error_handler'
	...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:74: in function 'handler'
	.../neovim/0.11.3/share/nvim/runtime/lua/vim/lsp/client.lua:682: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>

and

Java 
dap configuration failed
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.resolveMainClass"
stack traceback:
	...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
	...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
	...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:74: in function 'handler'
	.../neovim/0.11.3/share/nvim/runtime/lua/vim/lsp/client.lua:682: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>

That's insufficient. Please look at the post and provide same details.

That's insufficient. Please look at the post and provide same details.

Just updated the post. Thank you for helping!

Thank you. I'll try to reproduce it later today.

Can you try with the handlers in you jdtls setup contented?

I have sone recollection about that being changed in Mason.

I can't comment on details until I get to my computer but this is something you can try.

I've found your problem:

      { 'mason-org/mason-lspconfig.nvim', opts = {} },

opts = {} causes Lazy to run lspconfig.setup which in turn calls lspconfig.jdtls.setup before nvim-java has had the chance to insert its configuration into lspconfig.jdtls.setup.

@ShouryaRSharma

@ShouryaRSharma this is essentially misplaced:

opts = {
        servers = {
          jdtls = {
            settings = {
              java = {
                configuration = {
                  runtimes = {
                    {
                      name = "JavaSE-17",
                      path = "/opt/homebrew/opt/openjdk@17/bin/java",
                      default = true
                    },
                    {
                      name = "JavaSE-11",
                      path = "/opt/homebrew/opt/openjdk@11/bin/java",
                    }
                  }
                }
              },
            },
          },
        },
        setup = {
          jdtls = function()
            require("java").setup()
          end,
        },
}

The jdtls table should be passed to jdtls setup.

@s1n7ax, I'm addressing you since OP is not likely to show up. This issue is a configuration issue and should be closed.

I've found your problem:
      { 'mason-org/mason-lspconfig.nvim', opts = {} },
opts = {} causes Lazy to run lspconfig.setup which in turn calls lspconfig.jdtls.setup before nvim-java has had the chance to insert its configuration into lspconfig.jdtls.setup.

This solved my issue. Thank you!

I’m still getting the same error, even though my config looks a little different. I think it’s essentially the same setup.

java.lua

return {
	"nvim-java/nvim-java",
	config = function()
		require("java").setup()
	end,
	dependencies = {
		"neovim/nvim-lspconfig",
	},
}

lsp.lua

return {
	"neovim/nvim-lspconfig",
	dependencies = {
		"stevearc/conform.nvim",
		"williamboman/mason.nvim",
		"williamboman/mason-lspconfig.nvim",
		"hrsh7th/cmp-nvim-lsp",
		"hrsh7th/cmp-buffer",
		"hrsh7th/cmp-path",
		"hrsh7th/cmp-cmdline",
		"hrsh7th/nvim-cmp",
		"L3MON4D3/LuaSnip",
		"saadparwaiz1/cmp_luasnip",
		"j-hui/fidget.nvim",
	},

	config = function()
		local cmp = require("cmp")
		local cmp_lsp = require("cmp_nvim_lsp")
		local capabilities = vim.tbl_deep_extend(
			"force",
			{},
			vim.lsp.protocol.make_client_capabilities(),
			cmp_lsp.default_capabilities()
		)

		require("fidget").setup({})
		require("mason").setup()
		require("mason-lspconfig").setup({
			automatic_enable = {
				exclude = {
					-- "jdtls",
				},
			},
			ensure_installed = {
				"lua_ls",
				"rust_analyzer",
				"gopls",
				"tailwindcss",
			},

			handlers = {
				function(server_name) -- default handler (optional)
					require("lspconfig")[server_name].setup({
						capabilities = capabilities,
					})
				end,

				zls = function()
					local lspconfig = require("lspconfig")
					lspconfig.zls.setup({
						root_dir = lspconfig.util.root_pattern(".git", "build.zig", "zls.json"),
						settings = {
							zls = {
								enable_inlay_hints = true,
								enable_snippets = true,
								warn_style = true,
							},
						},
					})
					vim.g.zig_fmt_parse_errors = 0
					vim.g.zig_fmt_autosave = 0
				end,
				-- ["jdtls"] = function()
				-- 	local lspconfig = require("lspconfig")
				-- 	lspconfig.jdtls.setup({
				-- 		capabilities = capabilities,
				-- 	})
				-- end,
				["lua_ls"] = function()
					local lspconfig = require("lspconfig")
					lspconfig.lua_ls.setup({
						capabilities = capabilities,
						settings = {
							Lua = {
								format = {
									enable = true,
									-- Put format options here
									-- NOTE: the value should be STRING!!
									defaultConfig = {
										indent_style = "space",
										indent_size = "2",
									},
								},
							},
						},
					})
				end,
				["tailwindcss"] = function()
					local lspconfig = require("lspconfig")
					lspconfig.tailwindcss.setup({
						capabilities = capabilities,
						filetypes = {
							"html",
							"css",
							"scss",
							"javascript",
							"javascriptreact",
							"typescript",
							"typescriptreact",
							"vue",
							"svelte",
						},
						settings = {
							tailwindCSS = {
								experimental = {
									classRegex = {
										"tw`([^`]*)",
										'tw="([^"]*)',
										'tw={"([^"}]*)',
										"tw\\.\\w+`([^`]*)",
										"tw\\(.*?\\)`([^`]*)",
									},
								},
							},
						},
					})
				end,
			},
		})
...

Error msg

Error executing vim.schedule lua callback: ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:28:
dap configuration failed
RPC[Error] code_name = MethodNotFound, message = "No delegateCommandHandler for vscode.java.resolveMainClass"
stack traceback:
        ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:18: in function 'error_handler'
        ...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
        ...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:74: in function 'handler'
        /usr/share/nvim/runtime/lua/vim/lsp/client.lua:682: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>
stack traceback:
        [C]: in function 'error'
        ...al/share/nvim/lazy/nvim-java/lua/java/handlers/error.lua:28: in function 'error_handler'
        ...e/nvim/lazy/nvim-java-core/lua/java-core/utils/async.lua:32: in function 'callback'
        ...nvim-java-core/lua/java-core/ls/clients/jdtls-client.lua:74: in function 'handler'
        /usr/share/nvim/runtime/lua/vim/lsp/client.lua:682: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>

I’ve tried a few different variations of the config. Ultimately, I think the error is coming from mason-lspconfig, but I can’t seem to get it right.

I also have this problem

nvim-java

return {
	"nvim-java/nvim-java",
	dependencies = {
		"nvim-java/lua-async-await",
		"nvim-java/nvim-java-core",
		"nvim-java/nvim-java-test",
		"nvim-java/nvim-java-dap",
		"MunifTanjim/nui.nvim",
		"neovim/nvim-lspconfig",
		"mfussenegger/nvim-dap",
		"rcarriga/nvim-dap-ui",
	},
	config = function()
		local dap = require("dap")
		local dapui = require("dapui")
		require("java").setup()

		vim.keymap.set("n", "<F5>", dap.continue, { desc = "Debug: Start/Continue" })
		vim.keymap.set("n", "<F1>", dap.step_into, { desc = "Debug: Step Into" })
		vim.keymap.set("n", "<F2>", dap.step_over, { desc = "Debug: Step Over" })
		vim.keymap.set("n", "<F3>", dap.step_out, { desc = "Debug: Step Out" })
		vim.keymap.set("n", "<leader>b", dap.toggle_breakpoint, { desc = "Debug: Toggle Breakpoint" })
		vim.keymap.set("n", "<leader>B", function()
			dap.set_breakpoint(vim.fn.input("Breakpoint condition: "))
		end, { desc = "Debug: Set Breakpoint" })

		dapui.setup({
			-- Set icons to characters that are more likely to work in every terminal.
			--    Feel free to remove or use ones that you like more! :)
			--    Don't feel like these are good choices.
			icons = { expanded = "▾", collapsed = "▸", current_frame = "*" },
			controls = {
				icons = {
					pause = "⏸",
					play = "▶",
					step_into = "⏎",
					step_over = "⏭",
					step_out = "⏮",
					step_back = "b",
					run_last = "▶▶",
					terminate = "⏹",
					disconnect = "⏏",
				},
			},
		})

		vim.keymap.set("n", "<F7>", dapui.toggle, { desc = "Debug: See last session result." })

		dap.listeners.after.event_initialized["dapui_config"] = dapui.open
		dap.listeners.before.event_terminated["dapui_config"] = dapui.close
		dap.listeners.before.event_exited["dapui_config"] = dapui.close
	end,
}

lsp/jdtls.lua

local home = vim.env.HOME
return {
	cmd = { "jdtls" },
	filetypes = { "java" },
	root_dir = vim.fs.dirname(vim.fs.find({ "gradlew", ".git" }, { upward = true })[1]),
	init_options = {
		bundles = {
			vim.fn.glob(home .. "/.local/share/nvim/mason/packages/java-test/extension/server/*.jar", true),
			vim.fn.glob(
				home
					.. "/.local/share/nvim/mason/packages/java-debug-adapter/extension/server/com.microsoft.java.debug.plugin-*.jar",
				true
			),
		},
	},
}

I am using the new lspconfig setup, because required('lspconfig') is marked depricated...
What I also see is that in mason, there is a new version for java-test (0.40.1 -> 0.43.1) and spring-boot-tools (1.55.1 -> 1.59.0).
Pressing U to upgrade these two packages, reopening neovim will install the old versions again. Not sure if this might be the issue...

Furthermore, I don't really think that this might be an error, but rather a "miss-configuration".
I had a simmilar error in case for the dap-adapter, which was resolved by providing the .vscode/launch.json, I'm just not sure what type of configuration I need to provide the findTestTypesAndMethods handler...

We have released a next beta at v4.0.0 branch. Try it and let me know if this issue still persists.
https://github.com/nvim-java/nvim-java/tree/v4.0.0

Just tested no more of this error when launching with v4.0.0

Sorry if this is now obsolete - but, had the issue something to do with missing the step where the Test classes needed to be compiled first?

Also (not Sure if it was mentioned anywhere and is even correct, but) bundling every .jar file in the mason extension for tests will throw an error, leading to a simmilar case like this!?

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bug: No delegateCommandHandler for vscode.java.test.findTestTypesAndMethods #293

Did you check docs and existing issues?

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bug: No delegateCommandHandler for vscode.java.test.findTestTypesAndMethods #293

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Did you check docs and existing issues?

Neovim version (nvim -v)

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vasitzin commented on Aug 24, 2024

heddxh commented on Sep 7, 2024

kitparl commented on Sep 27, 2024

manumoreno commented on Oct 2, 2024

erlonbie commented on Oct 21, 2024

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s1n7ax commented on Oct 22, 2024

erlonbie commented on Nov 4, 2024

radon115 commented on Nov 16, 2024

adibfarrasy commented on Nov 16, 2024

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fromSmolsoft commented on Dec 2, 2024

Simplest steps to reproduce:

chenxin-yan commented on Aug 7, 2025

logrusx commented on Aug 8, 2025

chenxin-yan commented on Aug 8, 2025

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logrusx commented on Aug 8, 2025

chenxin-yan commented on Aug 8, 2025

logrusx commented on Aug 8, 2025

logrusx commented on Aug 8, 2025

logrusx commented on Aug 8, 2025

logrusx commented on Aug 8, 2025

chenxin-yan commented on Aug 8, 2025

twpowers commented on Aug 28, 2025

Captain-Ironbump commented on Nov 7, 2025

s1n7ax commented on Nov 30, 2025

Kiruel commented on Dec 3, 2025

Captain-Ironbump commented on Dec 3, 2025

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