JDK 1.6: Annotation Processing & Compiler Hack

Question

Hello,
I am currently using JDK 1.6.0_23
For one of the requirement, I am going with annotation processing & compiler Hack using Tools.jar available as part of JDK.
I have refered a PDF - "The Hacker's Guide to javac (PDF) by David Erni and Adrian Kuhn (2008)
" suggested from page of - http://openjdk.java.net/groups/compiler/
My requirement is below ->
Origional Source:
public void someMethod() {
}Modified Source:
public void someMethod() {
   int items = new example.Product().getItems();
} Below is my code to generate the variable declaration -
private TreeMaker make; // fetch it from somewhere
JCNewClass newProduct = make.NewClass(null, List.<JCExpression>nil(), make.Ident(names.fromString("example.Product")), List.<JCExpression>nil(), null);
JCFieldAccess fieldAccess = make.Select(newProduct, names.fromString("getItems"));
JCMethodInvocation getTimeMethodInvocation = make.Apply(List.<JCExpression>nil(), fieldAccess, List.<JCExpression>nil());
expression = getTimeMethodInvocation;
JCVariableDecl itemsDeclaration = make.VarDef(modifiers,name,varType,expression);
System.out.println(itemsDeclaration); // this prints int items = new example.Product().getItems(); This itemsDeclaration, I am adding to a List<JCStatement> of JCBlock of JCMethodDecl.
However modified code does not compile :(
If I make below changes - Modified does compile
1)
JCNewClass newProduct = make.NewClass(null, List.<JCExpression>nil(), make.Ident(names.fromString("Product")), List.<JCExpression>nil(), null);Product insteadof example.Product
2) Add belwo statement in the origional source code
import examle.Product; What exactly am I missing here ???
The AST tree is diffcult to understand with minimum documentation & without much help on the interent.
I hope this is correct forum, for my query.
It will be a great help.
Regards,
Vikas Parikh

Answer 1

Hello,
I couldn't contact them, as the white papaer didn't conatin any email address / contact info.
I have investigated myself on this & would like to share with you guys, so that any other developer
do not have to invest precious time like I have done.
To create a New Class, you require a JCExpression.
Below would work, if class already has imported Product class.
make.Ident(names.fromString("Product"))However, if class has not imported the Product class, then there are 2 options -
1) Create a Ident</pre> from <pre>Symbol (ClassSymbol)
2) Create a JCField</pre> from <pre>NameI used a later approach.
Regards,
Vikas Parikh
Edited by: 996153 on Mar 31, 2013 11:04 PM