Java adapter (#106)

* Initial java configuration

* Implement java adapter

* Remove debug output

* Fix Exception on jdtls server

* Resolve classPaths and mainClass

* Show errors

* Fix modulePaths and incompatible class version

* Allow failure when resolving mainClass/classPaths if set in configuration

* Fix for debug-java out-of-specification response

* Update Java adapter to new API

* Update Java adapter to new API

* Java: Move LSP config logic into debugger

* Java: Move source navigation special case to adapter

* Update README

* Java: Format

* Java: Adapt to new installer interface

* Java: Add jdtls connection timeout

README.md

@@ -41,6 +41,10 @@ This project comes with some pre-configured debuggers (They can be installed usi
 ##### PHP
 - See https://github.com/felixfbecker/vscode-php-debug
 
+##### Java
+- Requires [LSP](https://packagecontrol.io/packages/LSP) and [LSP-jdtls](https://packagecontrol.io/packages/LSP-jdtls)
+- See https://github.com/redhat-developer/vscode-java
+
 ## Setup
 - Open the debug panel
   - from the command palette `Debugger: Open`

modules/adapters/__init__.py

@@ -6,6 +6,7 @@
 from .python import Python
 from .go import Go
 from .php import PHP
+from .java import Java
 from .ruby import Ruby
 from .elixir import Elixir
 from .lua import Lua

modules/adapters/java.py

@@ -0,0 +1,145 @@
+from ..typecheck import Optional, Dict, Any, Tuple
+from ..import core
+from ..import dap
+from .import util
+
+import sublime
+import sublime_plugin
+import os
+import json
+
+
+class Java(dap.AdapterConfiguration):
+	jdtls_bridge: Dict[int, core.Future] = {}
+	jdtls_bridge_current_id = 0
+
+	type = 'java'
+	docs = 'https://github.com/redhat-developer/vscode-java/blob/master/README.md'
+
+	installer = util.OpenVsxInstaller(
+		type='java',
+		repo='vscjava/vscode-java-debug'
+	)
+
+	async def start(self, log, configuration):
+		# Make sure LSP and LSP-JDTLS are installed
+		pc_settings = sublime.load_settings('Package Control.sublime-settings')
+		installed_packages = pc_settings.get('installed_packages', [])
+		if 'LSP-jdtls' not in installed_packages or 'LSP' not in installed_packages:
+			raise core.Error('LSP and LSP-jdtls required to debug Java!')
+
+		# Get configuration from LSP
+		lsp_config = await self.get_configuration_from_lsp()
+
+		# Configure debugger
+		if 'cwd' not in configuration:
+			configuration['cwd'], _ = os.path.split(sublime.active_window().project_file_name())
+		if 'mainClass' not in configuration or not configuration['mainClass']:
+			configuration['mainClass'] = lsp_config['mainClass']
+		if 'classPaths' not in configuration:
+			configuration['classPaths'] = lsp_config['classPaths']
+		if 'modulePaths' not in configuration:
+			configuration['modulePaths'] = lsp_config['modulePaths']
+		if 'console' not in configuration:
+			configuration['console'] = 'internalConsole'
+		if lsp_config['enablePreview']:
+			if 'vmArgs' in configuration:
+				configuration['vmArgs'] += ' --enable-preview'
+			else:
+				configuration['vmArgs'] = '--enable-preview'
+
+		# Start debugging session on the LSP side
+		port = await self.lsp_execute_command('vscode.java.startDebugSession')
+
+		return dap.SocketTransport(log, 'localhost', port)
+
+	async def on_navigate_to_source(self, source: dap.SourceLocation) -> Optional[Tuple[str, str]]:
+		if not source.source.path or not source.source.path.startswith('jdt:'):
+			return None
+		content = await self.get_class_content_for_uri(source.source.path)
+		return content, 'text/java'
+
+	async def get_class_content_for_uri(self, uri):
+		return await self.lsp_request('java/classFileContents', {'uri': uri})
+
+	async def get_configuration_from_lsp(self) -> dict:
+		lsp_config = {}
+
+		mainclass_resp = await self.lsp_execute_command('vscode.java.resolveMainClass')
+		if not mainclass_resp or 'mainClass' not in mainclass_resp[0]:
+			raise core.Error('Failed to resolve main class')
+		else:
+			lsp_config['mainClass'] = mainclass_resp[0]['mainClass']
+			lsp_config['projectName'] = mainclass_resp[0].get('projectName', '')
+
+		classpath_response = await self.lsp_execute_command(
+			'vscode.java.resolveClasspath', [lsp_config['mainClass'], lsp_config['projectName']]
+		)
+		if not classpath_response[0] and not classpath_response[1]:
+			raise core.Error('Failed to resolve classpaths/modulepaths')
+		else:
+			lsp_config['modulePaths'] = classpath_response[0]
+			lsp_config['classPaths'] = classpath_response[1]
+
+		# See https://github.com/microsoft/vscode-java-debug/blob/b2a48319952b1af8a4a328fc95d2891de947df94/src/configurationProvider.ts#L297
+		lsp_config['enablePreview'] = await self.lsp_execute_command(
+		    'vscode.java.checkProjectSettings',
+		    [
+                json.dumps(
+                    {
+                        'className': lsp_config['mainClass'],
+                        'projectName': lsp_config['projectName'],
+                        'inheritedOptions': True,
+                        'expectedOptions': {
+                            'org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures': 'enabled'
+                        },
+                    }
+                )
+            ]
+		)
+
+		return lsp_config
+
+	async def lsp_execute_command(self, command, arguments=None):
+		request_params = { 'command': command }
+		if arguments:
+			request_params['arguments'] = arguments
+		return await self.lsp_request('workspace/executeCommand', request_params)
+
+	async def lsp_request(self, method, params) -> Any:
+		'''
+		Returns the response or raises an exception.
+		'''
+		future = core.Future()
+
+		id = Java.jdtls_bridge_current_id
+		Java.jdtls_bridge_current_id += 1
+		Java.jdtls_bridge[id] = future
+
+		# Send a request to JDTLS.
+		# NOTE: the active window might not match the debugger window but generally will
+		# TODO: a way to get the actual window.
+		sublime.active_window().run_command(
+			'debugger_jdtls_bridge_request',
+			{'id': id, 'callback_command': 'debugger_jdtls_bridge_response', 'method': method, 'params': params}
+		)
+		sublime.set_timeout(lambda: future.cancel(), 2500)
+		try:
+			command_response = await future
+		except core.CancelledError:
+			raise core.Error('Unable to connect to LSP-jdtls (timed out)')
+
+		del Java.jdtls_bridge[id]
+
+		if command_response['error']:
+			raise core.Error(command_response['error'])
+		return command_response['resp']
+
+
+class DebuggerJdtlsBridgeResponseCommand(sublime_plugin.WindowCommand):
+	def run(self, **args):
+		future = Java.jdtls_bridge.get(args['id'])
+		if not future:
+			print('Unable to find a future for this id')
+			return
+		future.set_result(args)

modules/dap/configuration.py

@@ -2,6 +2,7 @@
 from ..typecheck import *
 
 from ..import core
+from ..import dap
 from .transport import Transport
 
 import sublime
@@ -95,6 +96,14 @@ def settings(self, debugger: Debugger) -> list[Any]:
 	def ui(self, debugger: Debugger) -> Any|None:
 		...
 
+	async def on_navigate_to_source(self, source: dap.SourceLocation) -> Optional[Tuple[str, str]]:
+		"""
+		Allows the adapter to supply content when navigating to source.
+		Returns: None to keep the default behavior, else a tuple (content, mime_type)
+		"""
+		return None
+
+
 class Configuration(Dict[str, Any]):
 	def __init__(self, name: str, index: int, type: str, request: str, all: dict[str, Any]):
 		super().__init__(all)
@@ -179,4 +188,4 @@ def _expand_variables_and_platform(json: dict[str, Any], variables: dict[str, st
 	if variables := variables:
 		json = sublime.expand_variables(json, variables)
 
-	return json
+	return json

modules/dap/session.py

@@ -775,8 +775,11 @@ def set_selected(self, thread: Thread, frame: Optional[dap.StackFrame]):
 	# @NOTE threads_for_id will retain all threads for the entire session even if they are removed
 	@core.schedule
 	async def refresh_threads(self):
-		response = await self.request('threads', None)
-		threads: list[dap.Thread] = response['threads']
+		# the Java debugger requires an empty object instead of `None`
+		# See https://github.com/daveleroy/sublime_debugger/pull/106#issuecomment-793802989
+		response = await self.request('threads', {})
+		# See https://github.com/daveleroy/sublime_debugger/pull/106#issuecomment-795949070
+		threads: list[dap.Thread] = response.get('threads', [])
 
 		self.threads.clear()
 		for thread in threads:

modules/source_navigation.py

@@ -1,4 +1,6 @@
 from __future__ import annotations
+
+
 from .typecheck import *
 
 from .import core
@@ -15,6 +17,7 @@
 syntax_name_for_mime_type: dict[str|None, str] = {
 	'text/plain': 'text.plain',
 	'text/javascript': 'source.js',
+	'text/java': 'source.java',
 	'text/x-lldb.disassembly': 'source.disassembly',
 }
 
@@ -97,20 +100,27 @@ def clear_generated_view(self):
 			self.generated_view = None
 
 	async def navigate_to_source(self, source: dap.SourceLocation, move_cursor: bool = False) -> sublime.View:
+		# Check if adapter want to provide content
+		if self.debugger.session:
+			adapter_content = await self.debugger.session.adapter_configuration.on_navigate_to_source(source)
+		else:
+			adapter_content = None
 
 		# if we aren't going to reuse the previous generated view throw away any generated view
-		if not source.source.sourceReference:
+		if adapter_content or source.source.sourceReference:
 			self.clear_generated_view()
 
 		line = (source.line or 1) - 1
 		column = (source.column or 1) - 1
 
-		if source.source.sourceReference:
-			session = self.debugger.session
-			if not session:
-				raise core.Error('No Active Debug Session')
-
-			content, mime_type = await session.get_source(source.source)
+		if adapter_content or source.source.sourceReference:
+			if adapter_content:
+				content, mime_type = adapter_content
+			else:
+				session = self.debugger.session
+				if not session:
+					raise core.Error('No Active Debug Session')
+				content, mime_type = await session.get_source(source.source)
 
 			# the generated view was closed (no buffer) throw it away
 			if self.generated_view and not self.generated_view.buffer_id():
@@ -121,7 +131,6 @@ async def navigate_to_source(self, source: dap.SourceLocation, move_cursor: bool
 			self.generated_view = view
 			view.set_name(source.source.name or "")
 			view.set_read_only(False)
-
 
 			syntax = syntax_name_for_mime_type.get(mime_type, 'text.plain')
 			view.assign_syntax(sublime.find_syntax_by_scope(syntax)[0])
@@ -135,7 +144,5 @@ async def navigate_to_source(self, source: dap.SourceLocation, move_cursor: bool
 		else:
 			raise core.Error('source has no reference or path')
 
-
 		show_line(view, line, column, move_cursor)
-
 		return view

start.py

@@ -15,6 +15,7 @@
 
 # import all the commands so that sublime sees them
 from .modules.command import CommandsRegistry, DebuggerExecCommand, DebuggerCommand, DebuggerInputCommand
+from .modules.adapters.java import DebuggerJdtlsBridgeResponseCommand
 
 from .modules.core.sublime import DebuggerAsyncTextCommand, DebuggerEventsListener
 from .modules.debugger_output_panel import DebuggerConsoleListener
@@ -216,4 +217,4 @@ def on_view_gutter_clicked(self, view: sublime.View, line: int, button: int) ->
 				if source_breakpoints:
 					debugger.breakpoints.source.edit_breakpoints(source_breakpoints)
 
-		return True
+		return True