[stringtemplate-interest] NullPointerException from stgroup.getInstance()

Tue Jun 21 04:51:58 PDT 2011

Hi everybody,

after a long time I want to use stringtemplate in one of my projects againg. I worked with stringtemplate v2 and the early versions of 3. However, it seems that I cannot get v4 working.

This is my scenario:
In the folder "content/" there is the template file "decl.st" containing a very easy HTML page

<html>
<head>
<title>$title$</title>
</head>
<body>
<h1>$title$</h1>
</body>
</html>

The source code with stringtemplate v3 is this

StringTemplateGroup group = new StringTemplateGroup(null, "content/", DefaultTemplateLexer.class);
StringTemplate template = group.getInstanceOf("decl");
template.setAttribute("title", "Hello World");

And it works perfectly fine.

The equivalent in stringtemplate v4 (4.0.2) is - from what I figured and please correct me if I am wrong - 

STGroup group = new STGroupDir("content", '$', '$');
ST template = group.getInstanceOf("decl");	
template.add("title", "Hello World");

Now when I run this, I am seeing a NullPointerException:

Exception in thread "main" java.lang.NullPointerException
	at org.stringtemplate.v4.STGroup.loadTemplateFile(STGroup.java:624)
	at org.stringtemplate.v4.STGroupDir.loadTemplateFile(STGroupDir.java:165)
	at org.stringtemplate.v4.STGroupDir.load(STGroupDir.java:127)
	at org.stringtemplate.v4.STGroup.lookupTemplate(STGroup.java:226)
	at org.stringtemplate.v4.STGroup.getInstanceOf(STGroup.java:160)
	at Fancy.main(Fancy.java:15)

Also with stringtemplate v4.0.3 I am seeing the NPE.

What did I do wrong? I want to use v4 because of its cool new feature.

Alongside with the NullPointerException I get the following output in my eclipse console:

decl.st 1:1: invalid character '<'
decl.st 1:5: invalid character '>'
decl.st 2:1: invalid character '<'
decl.st 1:1: no viable alternative at input 'html'
decl.st 2:5: invalid character '>'
decl.st 3:1: invalid character '<'
decl.st 3:6: invalid character '>'
decl.st 3:7: invalid character '$'
decl.st 3:13: invalid character '$'
decl.st 3:15: invalid character '<'
decl.st 3:16: invalid character '/'
decl.st 3:21: invalid character '>'
decl.st 4:1: invalid character '<'
decl.st 4:2: invalid character '/'
decl.st 4:6: invalid character '>'
decl.st 5:1: invalid character '<'
decl.st 5:5: invalid character '>'
decl.st 6:1: invalid character '<'
decl.st 6:3: invalid character '>'
decl.st 6:4: invalid character '$'
decl.st 6:10: invalid character '$'
decl.st 6:12: invalid character '<'
decl.st 6:13: invalid character '/'
decl.st 6:15: invalid character '>'
decl.st 7:1: invalid character '<'
decl.st 7:2: invalid character '/'
decl.st 7:6: invalid character '>'
decl.st 8:1: invalid character '<'
decl.st 8:2: invalid character '/'
decl.st 8:6: invalid character '>'

What is this all about?

Thanks in advance and cheers,

- Daniel