[TAP5-1163] ClassTransformation Javassist Compile error accessing public field of non-component class

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 5.2.0
• Component/s: tapestry-core
• Labels: javassist
• Assignee: Unassigned
• Reporter: Howard Lewis Ship
• Created: 24/May/10 18:02
• Updated: 31/Aug/10 16:43
• Resolved: 31/Aug/10 16:43

Description

javassist.compiler.CompileError
_$get_category() not found in com.xxxx.data.CategoryTreeNode
Hide uninteresting stack frames Stack trace
javassist.compiler.TypeChecker.atMethodCallCore(TypeChecker.java:716)
javassist.compiler.TypeChecker.atCallExpr(TypeChecker.java:681)
javassist.compiler.JvstTypeChecker.atCallExpr(JvstTypeChecker.java:156)
javassist.compiler.ast.CallExpr.accept(CallExpr.java:45)
javassist.compiler.TypeChecker.atVariableAssign(TypeChecker.java:248)
javassist.compiler.TypeChecker.atAssignExpr(TypeChecker.java:217)
javassist.compiler.ast.AssignExpr.accept(AssignExpr.java:38)
javassist.compiler.CodeGen.doTypeCheck(CodeGen.java:241)
javassist.compiler.CodeGen.atStmnt(CodeGen.java:329)
javassist.compiler.ast.Stmnt.accept(Stmnt.java:49)
javassist.compiler.Javac.compileStmnt(Javac.java:568)
javassist.expr.FieldAccess.replace(FieldAccess.java:209)
org.apache.tapestry5.internal.services.InternalClassTransformationImpl$8.edit(InternalClassTransformationImpl.java:2141)
javassist.expr.ExprEditor.loopBody(ExprEditor.java:197)
javassist.expr.ExprEditor.doit(ExprEditor.java:90)
javassist.CtClassType.instrument(CtClassType.java:1289)
org.apache.tapestry5.internal.services.InternalClassTransformationImpl.replaceFieldAccess(InternalClassTransformationImpl.java:2147)
org.apache.tapestry5.internal.services.InternalClassTransformationImpl.performFieldTransformations(InternalClassTransformationImpl.java:2079)
org.apache.tapestry5.internal.services.InternalClassTransformationImpl.finish(InternalClassTransformationImpl.java:1811)
org.apache.tapestry5.internal.services.ComponentClassTransformerImpl.transformComponentClass(ComponentClassTransformerImpl.java:185)
org.apache.tapestry5.internal.services.ComponentInstantiatorSourceImpl.onLoad(ComponentInstantiatorSourceImpl.java:204)
javassist.Loader.findClass(Loader.java:340)
org.apache.tapestry5.internal.services.ComponentInstantiatorSourceImpl$PackageAwareLoader.findClass(ComponentInstantiatorSourceImpl.java:94)
javassist.Loader.loadClass(Loader.java:311)
java.lang.ClassLoader.loadClass(ClassLoader.java:250)
org.apache.tapestry5.internal.services.ComponentInstantiatorSourceImpl.findClass(ComponentInstantiatorSourceImpl.java:297)
org.apache.tapestry5.internal.services.ComponentInstantiatorSourceImpl.getInstantiator(ComponentInstantiatorSourceImpl.java:277)
org.apache.tapestry5.internal.pageload.PageLoaderImpl.createAssembler(PageLoaderImpl.java:193)
org.apache.tapestry5.internal.pageload.PageLoaderImpl.getAssembler(PageLoaderImpl.java:183)
org.apache.tapestry5.internal.pageload.PageLoaderImpl.loadPage(PageLoaderImpl.java:157)
org.apache.tapestry5.internal.services.PagePoolCache.checkout(PagePoolCache.java:210)
org.apache.tapestry5.internal.services.PagePoolImpl.checkout(PagePoolImpl.java:99)
org.apache.tapestry5.internal.services.RequestPageCacheImpl.get(RequestPageCacheImpl.java:51)
org.apache.tapestry5.internal.services.ComponentSourceImpl.getPage(ComponentSourceImpl.java:79)

I believe this is triggered by this code:

@Cached(watch = "currentNode")
public List<CategoryTreeNode> getSubNodesForCurrentNode()

{ if (currentNode.category == null) return Collections.emptyList(); return buildNodesForCategory(currentNode.category); }

CategoryTreeNode has a public field, category. This seems to be getting confused with the component field also named category.

Workaround: replace public fields with accessor methods.

Issue Links

• duplicates: TAP5-1222 Accessing a public field of a non-component object inside component code can result in a TransfomationException if the accessed field name matches the name of a component field