John J. Sung TA Consulting

Motivation for TraversalJ KL Enterprises identified AOP Enter into the AOP market early Add value by adding traversals to Java Contract COM 1205 Inc. TA Consulting Recommendations

High-Level System Overview traversal.trv TraversalJ traversal.java AspectJ traversal.class

System Components traversal.trv – TraversalJ file with class graph and traversal declarations TraversalJ – DemeterJ program by COM1205 traversal.java – Traversal code in AspectJ AspectJ – Aspect Oriented Programming Tool

TraversalJ Overview Implement using DemterJ –class dictionary –traversals Obtain Class Graph using AspectJ & DJ –CreateClassGraph.java Output traversal java code –AspectJTraversal.java

TraversalJ System traversal.trv COM1205 Middle-ware CreateClassGraph AspectJTraversaltraversal.java Main ClassGraphEvent(args, cg)

AspectJTraversal Java code to translate class graph + strategy into AspectJ code Processes DJ classes to do most of the work

TraversalJ Syntax ClassGraph Specification –ClassGraph cgvar; –ClassGraph cgvar = new ClassGraph(cg, “strategy”); Traversal Specification –declare traversal tvar : “strategy”; –declare traversal tvar(cgvar) : “strategy”;

TraversalJ Syntax Traversal Aspect Specification –aspect aspectName { – class graph declaration; – traversal declaration; –}

TraversalJ Syntax Example aspect MyTraversal { ClassGraph defaultCG; ClassGraph cg1 = new ClassGraph(defaultCG, “from * bypassing {java.lang.String} to *”); declare traversal t1: “from CompoundFile to SimpleFile”; declare traversal t2(cg1): “from CompoundFile to *”; }

Graphs and Traversals? Need to obtain Default Class Graph Keep track of declared Class Graphs Process traversal with specific Class Graph

TraversalJ System traversal.trv COM1205 Middle-ware CreateClassGraph AspectJTraversaltraversal.java Main ClassGraphEvent(args, cg)

ClassGraphListener/Factory ClassGraphListenerFactory –Need a way to obtain an instance of Middle-ware code –ClassGraphListener getNew(); ClassGraphListener –need a way to pass ClassGraph and arguments –abstract void ClassGraphEvent(String [] args, ClassGraph cg);

ClassGraphListener/Factory ClassGraphFactory ClassGraphListener MyListener getNew() new MyListener() ClassGraphListener CreateClassGraph

ClassGraphListener/Factory ClassGraphListener MyListener CreateClassGraph ClassGraphEvent(args, cg) Some Other Code

.prj File Copy CreateClassGraph.java and AspectJTravearsal.java into a directory Add the directory for the JAVADIR option in.prj file COMPILER = ajc TEST_ARGS = -d trav some.trv TEST_INPUT = some.trv

Testing TraversalJ Create some traversal file that implements a traversal that’s used in TraversalJ. Generate the.java file into a directory Add the directory for JAVADIRS Add code to call the traversal method in.beh files. Compile with traversal code and test

Fun with Recursion traversal.trv COM1205 Middle-ware DemeterJ traversal.java AspectJ TraversalJ

Debugging Strategy Traversals –You can use DJ to output traversal graphs –Look for error messages from demeterj General Debugging –have some variable debug to turn on debug output AspectJTraversal –debug : outputs processing information –addPrintingAdvice : Outputs code for printing traversal method calls

TraversalJ Project Phases Phase1 – Generate Class Dictionary for the traversal language Phase 2 – Implement –d directory option, basic traversal with default Class Graph Phase 3 – Implement Class Graph declaration and definition Phase 4 – Test code by generating a traversal used in TraversalJ

Project Submission Use ~jser/submit-proj README –How to compile your program –How to generate traversal code –How to test traversal code Due Date: March 8, 2002

Project Write Up Class Graph UML Diagram Document Traversals Document Testing of Traversal Code Evaluate software design and usefulness of TraversalJ Drop it off in class or mail box of TA Due Date: March 11, 2002

Questions? Reaches both KLE and TAC. ectJ_Usage.html