Introduce delegate command for java file paste

[hopehadfield]

Adds a delegate command that identifies whether or not some given clipboard text is a piece of java text and returns the correct path to the file to be created given relevant package declarations and/or type name.

Addresses redhat-developer/vscode-java#3323.

[rgrunber]

Overall looks pretty good. I'll have a closer look at the package logic later.

[rgrunber]

Overall, looks good. Just some things to clean up.

[robstryker]

It looks like you addressed everything @rgrunber mentioned and what I mentioned as well.

Just a small comment: sometimes when getting reviews, its nice to leave the fixes as a separate commit so reviewers can go verify the specific changes made in response to the review. We can always squash later or even squash as part of the merge button here in github.

But if you squash it first and force-push and essentially delete the previous version, it becomes harder to see what you changed upon review.

But again, seems like you fixed everything that was mentioned. +1 from me (although I admit to not using the ASTParser much just yet.)

[fbricon]

@robstryker I use the compare commit link for that purpose

[rgrunber]

Yeah, when I discovered the "force-pushed" was a link (eg. https://github.com/eclipse-jdtls/eclipse.jdt.ls/compare/0ab10ab5662c390309dc21882f1f92d02a769b52..c708293501fa5b8816675137516453450a93b833 ) it became easier to review though I agree that individual commits are more explicit.

[rgrunber]

I get the following error on Windows :

!ENTRY org.eclipse.jdt.ls.core 4 0 2023-12-13 00:50:08.563
!MESSAGE Error in calling delegate command handler
!STACK 0
java.lang.IllegalArgumentException: character to be escaped is missing
	at java.base/java.util.regex.Matcher.appendExpandedReplacement(Unknown Source)
	at java.base/java.util.regex.Matcher.appendReplacement(Unknown Source)
	at java.base/java.util.regex.Matcher.replaceAll(Unknown Source)
	at java.base/java.lang.String.replaceAll(Unknown Source)
	at org.eclipse.jdt.ls.core.internal.handlers.PasteEventHandler.searchForMatchingPackage(PasteEventHandler.java:413)
	at org.eclipse.jdt.ls.core.internal.handlers.PasteEventHandler.handleFilePasteEvent(PasteEventHandler.java:363)
	at org.eclipse.jdt.ls.core.internal.JDTDelegateCommandHandler.executeCommand(JDTDelegateCommandHandler.java:201)
	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(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

[rgrunber]

!ENTRY org.eclipse.jdt.ls.core 4 0 2023-12-13 16:51:34.982
!MESSAGE Error in calling delegate command handler
!STACK 0
java.nio.file.InvalidPathException: Illegal char <:> at index 2: /c:/Users/user/projects/foo\org\foo
	at java.base/sun.nio.fs.WindowsPathParser.normalize(Unknown Source)
	at java.base/sun.nio.fs.WindowsPathParser.parse(Unknown Source)
	at java.base/sun.nio.fs.WindowsPathParser.parse(Unknown Source)
	at java.base/sun.nio.fs.WindowsPath.parse(Unknown Source)
	at java.base/sun.nio.fs.WindowsFileSystem.getPath(Unknown Source)
	at java.base/java.nio.file.Path.of(Unknown Source)
	at java.base/java.nio.file.Paths.get(Unknown Source)
	at org.eclipse.jdt.ls.core.internal.handlers.PasteEventHandler.searchForMatchingPackage(PasteEventHandler.java:415)
	at org.eclipse.jdt.ls.core.internal.handlers.PasteEventHandler.handleFilePasteEvent(PasteEventHandler.java:364)
	at org.eclipse.jdt.ls.core.internal.JDTDelegateCommandHandler.executeCommand(JDTDelegateCommandHandler.java:201)
	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(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

Update: I don't think this is coming from the language server. The code seems to be correct, so I think it's an incorrect value passed by the client-side code.