Hi.
I'm researching the possibilities to port few of my projects to JAXB 2.0
and have a couple of questions.
My biggest concern is grammar model which was implemented in 1.0 by
com.sun.msv.grammar and com.sun.tools.xjc.grammar packages. Various
expressions (like SequenceExp) and items (like FieldItem) describe the
schema which is expressed by the classes generated by JAXB. Processing
these structures (for instance, with visitors) I could generate
schema-driven artifacts such as object verifiers.
Unfortunatelly I failed to find the analog of schema grammar model in
2.0. What I have is primarily CClassInfo/CPropertyInfo - I can see,
which properties made up a certain class, but what was the schema
structure that produces it? Was it a sequence or a choice or a more
complex construct?
HyperJAXB can be ported without this information, but jaxb-verification
and a new hijack project (not public yet) need to take schema grammar
into an account.
Basically, I need a hint on how to implement something like the attached
CheckVisitor.
Thanks!
Bye.
/lexi
package de.fzi.dbs.verification.addon;
import com.sun.codemodel.JBlock;
import com.sun.codemodel.JCodeModel;
import com.sun.codemodel.JConditional;
import com.sun.codemodel.JExpr;
import com.sun.codemodel.JExpression;
import com.sun.codemodel.JMethod;
import com.sun.codemodel.JOp;
import com.sun.codemodel.JPrimitiveType;
import com.sun.codemodel.JStatement;
import com.sun.msv.grammar.AttributeExp;
import com.sun.msv.grammar.ChoiceExp;
import com.sun.msv.grammar.ConcurExp;
import com.sun.msv.grammar.DataExp;
import com.sun.msv.grammar.ElementExp;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.InterleaveExp;
import com.sun.msv.grammar.ListExp;
import com.sun.msv.grammar.MixedExp;
import com.sun.msv.grammar.OneOrMoreExp;
import com.sun.msv.grammar.OtherExp;
import com.sun.msv.grammar.ReferenceExp;
import com.sun.msv.grammar.SequenceExp;
import com.sun.msv.grammar.ValueExp;
import com.sun.msv.grammar.xmlschema.OccurrenceExp;
import com.sun.tools.xjc.generator.ClassContext;
import com.sun.tools.xjc.grammar.ClassItem;
import com.sun.tools.xjc.grammar.ExternalItem;
import com.sun.tools.xjc.grammar.FieldItem;
import com.sun.tools.xjc.grammar.FieldUse;
import com.sun.tools.xjc.grammar.IgnoreItem;
import com.sun.tools.xjc.grammar.InterfaceItem;
import com.sun.tools.xjc.grammar.PrimitiveItem;
import com.sun.tools.xjc.grammar.SuperClassItem;
import de.fzi.dbs.jaxb.addon.Util;
import de.fzi.dbs.verification.event.VerificationEvent;
import de.fzi.dbs.verification.event.VerificationEventLocator;
import de.fzi.dbs.verification.event.structure.EmptyFieldProblem;
import de.fzi.dbs.verification.event.structure.TooFewElementsProblem;
import de.fzi.dbs.verification.event.structure.TooManyElementsProblem;
/**
* This visitor generates statements that check structure of the master object according to the
* visited expression.
*
* @author Aleksei Valikov
*/
public class CheckVisitor extends BGMExpressionVisitor
{
/**
* Code model.
*/
protected final JCodeModel codeModel;
/**
* Class context.
*/
protected final ClassContext classContext;
/**
* Event handler.
*/
protected final JExpression handler;
/**
* Parent locator.
*/
protected final JExpression parentLocator;
/**
* Master object.
*/
protected final JExpression master;
/**
* Constructs a check visitor.
*
* @param classContext class context.
* @param handler validation event handler.
* @param parentLocator parent locator.
* @param master master object
*/
public CheckVisitor(final ClassContext classContext, final JExpression handler, final JExpression parentLocator, final JExpression master)
{
this.classContext = classContext;
codeModel = classContext.parent.getCodeModel();
this.handler = handler;
this.parentLocator = parentLocator;
this.master = master;
}
/**
* Visits an occurence expression.
* @param exp the occurence expression.
* @return Result of the processing.
*/
public Object onOccurrenceExp(final OccurrenceExp exp)
{
// Simply visit the item expression.
final JBlock block = (JBlock) exp.itemExp.visit(this);
return block;
}
public Object onOther(final OtherExp exp)
{
if (exp instanceof OccurrenceExp)
{
return onOccurrenceExp((OccurrenceExp) exp);
}
else
{
return super.onOther(exp);
}
}
public Object onClass(final ClassItem item)
{
return null;
}
public Object onExternal(final ExternalItem item)
{
return null;
}
public Object onField(final FieldItem fieldItem)
{
final JBlock block = JBlock.dummyInstance.block();
// final JExpression locator = JExpr._new(classContext.parent.getCodeModel().ref(VerificationEventLocator.class)).arg(this.parentLocator).arg(master).arg(JExpr.lit(fieldItem.name));
final FieldUse fieldUse = classContext.target.getField(fieldItem.name);
final JMethod getter = Util.getFieldInterfaceGetter(classContext, fieldItem);
JBlock checkBlock = block;
// If field is not a constant field
if (null != getter)
{
final JExpression field = JExpr.invoke(master, getter);
if (fieldUse.type.isPrimitive())
{
block.directStatement("// No check for primitive values");
}
else
{
/// if (null == master.get<Field>()
final JConditional ifNullConditional = block._if(JOp.eq(JExpr._null(), field));
final JBlock ifNull = ifNullConditional._then();
final JBlock ifNotNull = ifNullConditional._else();
// A, A?
if (fieldUse.multiplicity.isAtMostOnce())
{
if (fieldUse.multiplicity.isOptional())
{
ifNull.directStatement("// Optional field - nothing to report");
}
else
{
ifNull.directStatement("// Report missing object");
ifNull.invoke(handler, "handleEvent").arg(JExpr._new(codeModel.ref(VerificationEvent.class)).
arg(JExpr._new(codeModel.ref(VerificationEventLocator.class)).arg(parentLocator).arg(master).arg(JExpr.lit(fieldUse.name))).
arg(JExpr._new(codeModel.ref(EmptyFieldProblem.class))));
}
}
// A*, A+
else
{
if (fieldItem.multiplicity.isOptional())
{
ifNull.directStatement("// Optional - nothing to report");
}
else
{
ifNull.directStatement("// Report missing object");
ifNull.invoke(handler, "handleEvent").arg(JExpr._new(codeModel.ref(VerificationEvent.class)).
arg(JExpr._new(codeModel.ref(VerificationEventLocator.class)).arg(parentLocator).arg(master).arg(JExpr.lit(fieldUse.name))).
arg(JExpr._new(codeModel.ref(EmptyFieldProblem.class))));
}
ifNotNull.directStatement("// Check count");
final JExpression count = JExpr.invoke(field, "size");
final JExpression minCount = JExpr.lit(fieldUse.multiplicity.min);
/// if (getField().size() < minOccurs)
final JBlock minOccursViolated = ifNotNull.
_if(JOp.lt(count, minCount))._then();
minOccursViolated.directStatement("// Report minimum of occurences violated");
minOccursViolated.invoke(handler, "handleEvent").arg(JExpr._new(codeModel.ref(VerificationEvent.class)).
arg(JExpr._new(codeModel.ref(VerificationEventLocator.class)).
arg(parentLocator).
arg(master).
arg(JExpr.lit(fieldUse.name))).
arg(JExpr._new(codeModel.ref(TooFewElementsProblem.class)).arg(count).arg(minCount)));
// If maxOccurs is not "unbounded"
if (fieldUse.multiplicity.max != null)
{
final JExpression maxCount = JExpr.lit(fieldUse.multiplicity.max.intValue());
/// if (getField().size() > maxOccurs)
final JBlock maxOccursViolated = ifNotNull.
_if(JOp.gt(count, JExpr.lit(fieldUse.multiplicity.max.intValue())))._then();
maxOccursViolated.directStatement("// Report maximum of occurences violated");
maxOccursViolated.invoke(handler, "handleEvent").arg(JExpr._new(codeModel.ref(VerificationEvent.class)).
arg(JExpr._new(codeModel.ref(VerificationEventLocator.class)).
arg(parentLocator).
arg(master).
arg(JExpr.lit(fieldUse.name))).
arg(JExpr._new(codeModel.ref(TooManyElementsProblem.class)).arg(count).arg(maxCount)));
}
}
ifNotNull.directStatement("// Check value");
checkBlock = ifNotNull;
}
checkBlock.invoke("check" + fieldUse.name).arg(parentLocator).arg(handler).arg(master).
arg((fieldUse.multiplicity.isAtMostOnce() && fieldUse.type.isPrimitive()) ?
((JPrimitiveType) fieldUse.type).wrap(field) : field);
}
return block;
}
public Object onIgnore(final IgnoreItem item)
{
final JBlock block = JBlock.dummyInstance.block();
return block;
}
public Object onInterface(final InterfaceItem item)
{
return null;
}
public Object onPrimitive(final PrimitiveItem item)
{
return null;
}
public Object onSuper(final SuperClassItem item)
{
final JBlock block = JBlock.dummyInstance.block();
block.invoke(JExpr.ref("super"), "check").arg(parentLocator).arg(handler).arg(master);
return block;
}
public Object onAnyString()
{
return null;
}
public Object onEpsilon()
{
final JBlock block = JBlock.dummyInstance.block();
return block;
}
public Object onNullSet()
{
return null;
}
public Object onAttribute(final AttributeExp exp)
{
return null;
}
public Object onConcur(final ConcurExp p)
{
return null;
}
public Object onData(final DataExp exp)
{
return null;
}
public Object onElement(final ElementExp exp)
{
final JBlock block = JBlock.dummyInstance.block();
final JStatement statement = (JStatement) exp.contentModel.visit(this);
block.add(statement);
return block;
}
public Object onInterleave(final InterleaveExp p)
{
return null;
}
public Object onList(final ListExp exp)
{
return null;
}
public Object onMixed(final MixedExp exp)
{
return null;
}
public Object onOneOrMore(final OneOrMoreExp exp)
{
final JBlock block = (JBlock) exp.exp.visit(this);
return block;
}
public Object onRef(final ReferenceExp exp)
{
return null;
}
public Object onSequence(final SequenceExp exp)
{
final JBlock block = JBlock.dummyInstance.block();
final JBlock left = (JBlock) exp.exp1.visit(this);
final JBlock right = (JBlock) exp.exp2.visit(this);
block.add(left);
block.add(right);
return block;
}
public Object onChoice(final ChoiceExp exp)
{
final JBlock block = JBlock.dummyInstance.block();
final JExpression leftExists = (JExpression) exp.exp1.visit(new ExistsVisitor(classContext, master));
final JExpression rightExists = (JExpression) exp.exp2.visit(new ExistsVisitor(classContext, master));
if (exp.exp2 == Expression.epsilon)
{
final JConditional l = block._if(leftExists);
l._then().directStatement("// If left exists");
l._then().add((JBlock) exp.exp1.visit(this));
return block;
}
else if (exp.exp1 == Expression.epsilon)
{
final JConditional r = block._if(rightExists);
r._then().directStatement("// If right exists");
r._then().add((JBlock) exp.exp2.visit(this));
return block;
}
else
{
block.directStatement("// Choice");
block.directStatement("// If right exists");
final JConditional r = block._if(rightExists);
r._then().directStatement("// Right left");
r._then().add((JBlock) exp.exp2.visit(this));
r._then().directStatement("// todo: check left does not exists???");
r._else().directStatement("// Right does not exist, left must exist");
r._else().add((JBlock) exp.exp1.visit(this));
// final JConditional lnr = block._if(JOp.not(rightExists));
// lnr._then().directStatement("// If right does not exist, left must exist");
// lnr._then().add((JBlock) exp.exp1.visit(this));
//
//
// final JConditional nlnr = block._if(leftExists);
// nlnr._then().directStatement("// If left exists, right must not exist");
// nlnr._then().add((JBlock) exp.exp1.visit(this));
// nlnr._then().directStatement("// todo: check that right is absent. how?");
}
return block;
}
public Object onValue(final ValueExp exp)
{
return null;
}
}