lsp-zero + jdtls + gradle

[zivoznovich]

I have installed lsp zero and jdtls with mason.
added the default config

local lsp_zero = require('lsp-zero')
lsp_zero.on_attach(function(client, bufnr)
-- see :help lsp-zero-keybindings
-- to learn the available actions
lsp_zero.default_keymaps({buffer = bufnr})
end)

require('mason').setup({})
require('mason-lspconfig').setup({
-- Replace the language servers listed here
-- with the ones you want to install
ensure_installed = {'tsserver', 'lua_ls', 'jdtls'},
handlers = {
lsp_zero.default_setup
},
})

auto-completion works.

I cannot run gradle commands though.
how should I solve this?