return {
  jdtls = function(opts)
    -- use this function notation to build some variables
    local root_markers = { ".git", "mvnw", "gradlew", "pom.xml", "build.gradle" }
    local root_dir = require("jdtls.setup").find_root(root_markers)

    -- calculate workspace dir
    local project_name = vim.fn.fnamemodify(vim.fn.getcwd(), ":p:h:t")
    local workspace_dir = vim.fn.stdpath "data" .. "/site/java/workspace-root/" .. project_name
    os.execute("mkdir " .. workspace_dir)

    -- get the mason install path
    local install_path = require("mason-registry").get_package("jdtls"):get_install_path()

    -- get the current OS
    local os
    print(os)
    if vim.fn.has "macunix" then
      os = "mac"
    elseif vim.fn.has "win32" then
      os = "win"
    else
      os = "linux"
    end

    -- return the server config
    return {
      cmd = {
        "java",
        "-Declipse.application=org.eclipse.jdt.ls.core.id1",
        "-Dosgi.bundles.defaultStartLevel=4",
        "-Declipse.product=org.eclipse.jdt.ls.core.product",
        "-Dlog.protocol=true",
        "-Dlog.level=ALL",
        "-javaagent:" .. install_path .. "/lombok.jar",
        "-Xms1g",
        "--add-modules=ALL-SYSTEM",
        "--add-opens",
        "java.base/java.util=ALL-UNNAMED",
        "--add-opens",
        "java.base/java.lang=ALL-UNNAMED",
        "-jar",
        vim.fn.glob(install_path .. "/plugins/org.eclipse.equinox.launcher_*.jar"),
        "-configuration",
        install_path .. "/config_" .. os,
        "-data",
        workspace_dir,
      },

      root_dir = root_dir,
    }
  end,
}