Migrate to mason.nvim and setup jdtls

ftplugin/java.lua

@@ -0,0 +1,22 @@
+local mylsp = require("my-lsp")
+local path = require("mason-core.path")
+
+local function mason_package(...)
+	return path.concat{vim.fn.stdpath("data"), "mason", "packages", ...}
+end
+
+local bundles = vim.fn.glob(mason_package("java-debug-adapter", "extension", "server", "com.microsoft.java.debug.plugin-*.jar"), true, true)
+local extra_bundles = vim.fn.glob(mason_package("java-test", "extension", "server", "*.jar"), true, true)
+vim.list_extend(bundles, extra_bundles)
+
+require('jdtls').start_or_attach({
+	cmd = {mason_package("jdtls", "bin", "jdtls") },
+	on_attach = function(client, bufnr)
+		require'jdtls.setup'.add_commands()
+		require'jdtls'.setup_dap()
+		mylsp.on_attach(client, bufnr)
+	end,
+	init_options = {
+		bundles = extra_bundles
+	}
+})