Great resource!
I would like to know whether we can find the information like package name, file name, method names, getter and setter methods of an object from a java file. I am trying to figure this out, and am hoping your tutorial would be of help. Please send me an email if you have more information regarding my specific issue.

Thanks a lot.
Gem.

thanks in advance

bye

Your code needs to have the main method

public static void main(String args[])

for it to be entry point of execution

Thanks for your reply. I found these code are contained in the generated ExpressionParser.java. Why when i try to run it, it complains “The selection does not contain a main type”? Am i missing something? Why my eclipse does not recognize these code as my main type? Sorry if this is a stupid question but please help me.

Thanks,
Kam Ting

The parser generator generates all the classes requried for parsing the langugage, to use the parser you would need to invoke the parser. Here is a sample code to invoke the parser.
#
public static void main(String args[]) throws Exception {
#
ExpressionParser parser = new ExpressionParser(new java.io.FileReader(args[0]));
#
//ExpressionParser parser = new ExpressionParser(System.in);
#
ASTstart expr=parser.start();
#
ExpressionVisitor v=new ExpressionVisitor();
#
System.out.println(expr.jjtAccept(v,null));
#
}
#
}
#

I’m new to javacc. When i try to run the generated code, i got the following error.

Exception in thread “main” java.lang.NoClassDefFoundError: ExpressionParser/java

Have i did anything wrong? Please help me, thanks.

Ada

You have completed the lexical and the syntactical analyis phase, your next step would be to generate the abstract syntax tree. You can do this using JJTree, The abstract syntax tree would be the hierachical view of the program, as shown in the diagram in the tutorial. Once the tree is created you could traverse the tree and execute each node.

I recommend you to download the source code, I have a very simple example and I think you would find it useful. I have used javacc and jjtree in the example

anand