Java-Debug is not always conforming the Debugger Adapter Protocol

• Commands that have arguments set to null throw an exception:

  jdtls: 08.03.2021, 23:12:44 Error parsing message: com.google.gson.JsonSyntaxException: Expected a com.google.gson.JsonObject but was com.google.gson.JsonNull
  Expected a com.google.gson.JsonObject but was com.google.gson.JsonNull
  com.google.gson.JsonSyntaxException: Expected a com.google.gson.JsonObject but was com.google.gson.JsonNull
      at com.google.gson.internal.bind.TypeAdapters$35$1.read(TypeAdapters.java:897)
      at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:131)
      at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:222)
      at com.google.gson.Gson.fromJson(Gson.java:932)
      at com.google.gson.Gson.fromJson(Gson.java:897)
      at com.google.gson.Gson.fromJson(Gson.java:846)
      at com.google.gson.Gson.fromJson(Gson.java:817)
      at com.microsoft.java.debug.core.protocol.JsonUtils.fromJson(JsonUtils.java:26)
      at com.microsoft.java.debug.core.protocol.AbstractProtocolServer.processData(AbstractProtocolServer.java:219)
      at com.microsoft.java.debug.core.protocol.AbstractProtocolServer.run(AbstractProtocolServer.java:98)
      at com.microsoft.java.debug.core.adapter.ProtocolServer.run(ProtocolServer.java:61)
      at com.microsoft.java.debug.plugin.internal.JavaDebugServer$2.run(JavaDebugServer.java:136)
      at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
      at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
      at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
      at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
      at java.base/java.lang.Thread.run(Thread.java:832)
  

  However, commands that do not need arguments, e.g. (configurationDone, threads) should be able to set arguments to null as the Thread Request does not set any restrictions. See here.

• The response to threads request does not always contain the threads key.
  Protocol:

  ⟸ request/threads(8) :: {}
  ⟸ request/threads(9) :: {}
  ⟸ request/threads(10) :: {}
  ⟸ request/threads(11) :: {}
  ⟸ request/threads(12) :: {}
  ⟸ request/threads(13) :: {}
  ⟹ response/threads(8) :: None
  ⟹ response/threads(9) :: None
  ⟹ response/threads(10) :: None
  ⟹ response/threads(11) :: None
  ⟹ response/threads(12) :: None
  ⟹ response/threads(13) :: None
  

  See here.

• When stepping into classes that are not represented by a project file, Java-Debug returns a path with URI scheme jdt:// which then can be used to retrieve the class content using the java/classFileContents LSP request. Java-Debug should instead set the sourceReference value > 0 and the contents of the source must be retrieved through the source request (See https://github.com/microsoft/java-debug/issues/259#issuecomment-695097967).
  This requires a special workaround in https://github.com/daveleroy/sublime_debugger/pull/106.

Bắt đầu với đường dẫn giao thức qua JsonUtils.java, AbstractProtocolServer.java và ProtocolServer.java, sau đó tái hiện các request với đối số null và các request threads lặp lại. Kiểm tra response threads của DAP và việc xử lý source cho các class được trả về với URI jdt://. Hoàn tất khi các đối số null không còn gây ra exception, các response threads có chứa threads và các class không thuộc project sử dụng sourceReference với source request.