Re: [jgit-dev] How To Checkout with a Specified Tag using CheckoutComman

["Halstrick, Christian" <christian.halstrick@xxxxxxx>]

Hi,

I guess the NullPointerException is not thrown by 

	git.checkout().setName("my_tag").call()

but because you are later trying to access the result of this call. Look at the JavaDoc: CheckoutCommand.call() will return something non-null if it created a new branch. If you checkout an existing branch or a tag the result will be null. Checkout this code which shows howto checkout a tag:

	File tmpDir = new File(System.getProperty("java.io.tmpdir"),
		"JGitTest_CloneAndCheckoutExample_"
		+ System.currentTimeMillis());
	tmpDir.mkdirs();
	Git git = Git.cloneRepository().setURI("https://github.com/chalstrick/dondalfi.git";).setDirectory(tmpDir).call();
	for (Ref tag: git.tagList().call())
		System.out.println("Found tag: "+tag.getName());
	Ref newBranch = git.checkout().setName("1.0").call();
	System.out.println("Checked out 1.0. Newly created branch: "+((newBranch==null) ? "null" : newBranch.getName()));
	newBranch = git.checkout().setName("1.1").call();
	// Expect a RefNotFoundException here

Ciao
  Chris