java - StringTemplate: how to detect, if variable in tempate is not explicitly set? -

java - StringTemplate: how to detect, if variable in tempate is not explicitly set? -

i using stringtemplate auto-generate configuration files , it's error, if user haven't defined of variables.

stringtemplate replace undefined variables (i mean $var$) empty string , error remain undetected. e.g.:

some_property=$some_property$

is rendered into:

some_property=

how forcefulness stringtemplate raise exception, if variable in template not explicitly defined using

stringtemplate.setattribute(key, value)

?

with stringtemplate 4 error listener informed undefined attribute. custom error-listener can handle required. example:

st tmp = new st("hello <name>!"); tmp.write(new noindentwriter(new stringwriter()), new sterrorlistener() { @override public void runtimeerror(stmessage msg) { if(msg.error == errortype.no_such_attribute) system.out.println("attribute not defined: "+ msg.arg); } @override public void compiletimeerror(stmessage msg) { } @override public void ioerror(stmessage msg) { } @override public void internalerror(stmessage msg) { } });

java string stringtemplate