Hot Code Replace returns `Cannot find any changed classes for hot replace!` message

Question

Hot Code Replace returns `Cannot find any changed classes for hot replace!` message

peerpalo opened this issue 4 months ago · comments

Similar to #1474, in this particular project configuration any attempt to use Hot Code Replace will produce a NullPointerException in Java Debugger. You can find a minimum sample project attached at the bottom.

[Error - 5:37:33 PM] May 25, 2024, 5:37:33 PM Problems occurred when invoking code from plug-in: "org.eclipse.jdt.ls.core".
Cannot invoke "java.lang.String.split(java.lang.String)" because "fullyQualifiedTypeName" is null
java.lang.NullPointerException: Cannot invoke "java.lang.String.split(java.lang.String)" because "fullyQualifiedTypeName" is null
	at com.microsoft.java.debug.plugin.internal.ResolveClasspathsHandler.getJavaProjectFromType(ResolveClasspathsHandler.java:117)
	at com.microsoft.java.debug.plugin.internal.Compile.compile(Compile.java:52)
	at com.microsoft.java.debug.plugin.internal.JavaDebugDelegateCommandHandler.executeCommand(JavaDebugDelegateCommandHandler.java:72)
	at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler$1.run(WorkspaceExecuteCommandHandler.java:230)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
	at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler.executeCommand(WorkspaceExecuteCommandHandler.java:220)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$4(JDTLanguageServer.java:616)
	at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)

[Error - 5:37:33 PM] May 25, 2024, 5:37:33 PM Error in calling delegate command handler
Cannot invoke "java.lang.String.split(java.lang.String)" because "fullyQualifiedTypeName" is null
java.lang.NullPointerException: Cannot invoke "java.lang.String.split(java.lang.String)" because "fullyQualifiedTypeName" is null
	at com.microsoft.java.debug.plugin.internal.ResolveClasspathsHandler.getJavaProjectFromType(ResolveClasspathsHandler.java:117)
	at com.microsoft.java.debug.plugin.internal.Compile.compile(Compile.java:52)
	at com.microsoft.java.debug.plugin.internal.JavaDebugDelegateCommandHandler.executeCommand(JavaDebugDelegateCommandHandler.java:72)
	at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler$1.run(WorkspaceExecuteCommandHandler.java:230)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
	at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler.executeCommand(WorkspaceExecuteCommandHandler.java:220)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$4(JDTLanguageServer.java:616)
	at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)

[Error - 5:37:33 PM] Request workspace/executeCommand failed.
  Message: Cannot invoke "java.lang.String.split(java.lang.String)" because "fullyQualifiedTypeName" is null
  Code: -32001 
[object Object]

Environment

Operating System: Windows 11 23H2 (OS Build 22631.3593)
JDK version: openjdk 17.0.6 2023-01-17, IBM Semeru Runtime Open Edition 17.0.6.0 (build 17.0.6+10)
Visual Studio Code version: 1.89.1
Java extension version: v1.30.0
Java Debugger extension version: v0.57.0

Steps To Reproduce

Start a Maven Spring Boot project with multiple dependencies
Attach debugger
Change code, save and press "Hot Code Replace"

Additional Informations

https://github.com/peerpalo/hotcode-exception

Andrei Tudor · Answer 1 · Tue May 28 2024 16:59:44 GMT+0800 (China Standard Time)

@peerpalo I got it to work, I've downgraded the "Debugger for Java" extension to v0.50.0 and it started to work, slowly, but it restarts now and detects changes (my project is huge so I expected the slow restart)

I haven't tried higher/newer versions of the extension

peerpalo · Answer 2 · Wed May 29 2024 16:40:34 GMT+0800 (China Standard Time)

Thanks @Alexand3r, did some trial and errors and latest working version is v0.53.0, so v0.54.0 broke something on this specific configuration. Maybe it's this?

slowly, but it restarts now and detects changes

In my case it's really impossible to use it, very slow, could take more than 5 minutes

Jinbo Wang · Answer 3 · Fri May 31 2024 11:14:34 GMT+0800 (China Standard Time)

this duplicates with microsoft/java-debug#554. It happens when the autobuild is disabled. We will provide a fix soon.

Currently a workaround is to enable autobuild via java.autobuild.enabled. With this, Hot code replace still works.

Anonymous2416 · Answer 4 · Sat Jun 01 2024 12:56:30 GMT+0800 (China Standard Time)

Currently a workaround is to enable autobuild via java.autobuild.enabled. With this, Hot code replace still works.

im working in vscode making forge Minecraft mods, for me it says "Cannot find any changed classes for hot replace " no matter what I do.

I've tried new projects, I've tried setting hot code replace to "auto".

Anonymous2416 · Answer 5 · Tue Jun 04 2024 21:21:35 GMT+0800 (China Standard Time)

@jdneo awesome. that's great. Am I able to get the fix now or I have to wait for it to be merged. Do I just do what you have under "How to test the change" section and it'll be fine or no?

Sheng Chen · Answer 6 · Wed Jun 05 2024 08:47:44 GMT+0800 (China Standard Time)

@Anonymous2416 If you want to build it locally to try the change, you can follow the How to test the change section.

If you are not blocked by this issue, I would recommend to wait for it being merged and use the nightly build. I'll inform here once the nightly build is released.

Anonymous2416 · Answer 7 · Wed Jun 05 2024 19:29:24 GMT+0800 (China Standard Time)

@Anonymous2416 If you want to build it locally to try the change, you can follow the How to test the change section.

I tried that but still have the same issue Cannot find any changed classes for hot replace

Sheng Chen · Answer 8 · Wed Jun 05 2024 20:15:12 GMT+0800 (China Standard Time)

@Anonymous2416 Can you give a sample project with a repro steps?

Anonymous2416 · Answer 9 · Wed Jun 05 2024 20:46:40 GMT+0800 (China Standard Time)

@jdneo https://github.com/Anonymous2416/GrenadeTest
need jdk 17

clone repo and open VSCode
wait for java/gradle stuff to build/run
run gradle task genVSCodeRuns
run gradle task runClient in debug
open ThrowableGrenadeRenderer.java and comment out lines 36
test out hot code replace

let me know if there's any issues running the project or anything at all. thanks

Sheng Chen · Answer 10 · Thu Jun 06 2024 10:28:16 GMT+0800 (China Standard Time)

I don't know how to validate the effect after comment out the line 36. But the UI response shows that the HCR works.

See:

after.mp4

Please make sure that:

Jar file in the vscode-gradle extension is replaced as described in microsoft/java-debug#555.
The debugger is built according to the new PR.
After you changed your file and before you trigger the HCR, makes sure you save the file.

Anonymous2416 · Answer 11 · Thu Jun 06 2024 20:37:33 GMT+0800 (China Standard Time)

@jdneo I replaced the jar file. what do you mean build the debugger according to the PR?
Im just replacing the jar file and launching vscode, I need to do anything else?

Anonymous2416 · Answer 12 · Thu Jun 06 2024 20:44:48 GMT+0800 (China Standard Time)

@jdneo I replaced the jar file. what do you mean build the debugger according to the PR? Im just replacing the jar file and launching vscode, I need to do anything else?

I also see this when I run runClient in debug mode

Anonymous2416 · Answer 13 · Thu Jun 06 2024 23:33:00 GMT+0800 (China Standard Time)

nvm I built it and was able to get it working. Thank you! :)