org.jvnet.hk2.config.generator.TypeMath Maven / Gradle / Ivy
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package org.jvnet.hk2.config.generator;
import com.sun.codemodel.JExpr;
import com.sun.codemodel.JExpression;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.TypeParameterElement;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.PrimitiveType;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.type.TypeVariable;
import javax.lang.model.type.WildcardType;
import javax.lang.model.util.SimpleTypeVisitor6;
import java.util.Collection;
import java.util.Locale;
/**
* Defines several type arithemetic operations.
* @author Kohsuke Kawaguchi
*/
class TypeMath {
protected final ProcessingEnvironment env;
/**
* Given a declaration X and mirror Y, finds the parametrization of Z=X<...> such that
* Y is assignable to Z.
*/
final SimpleTypeVisitor6 baseClassFinder = new SimpleTypeVisitor6() {
@Override
public TypeMirror visitDeclared(DeclaredType t, TypeElement sup) {
TypeMirror r = onDeclaredType(t, sup);
if (r != null) return r;
Element e = t.asElement();
switch (e.getKind()) {
case CLASS: {
// otherwise recursively apply super class and base types
TypeMirror sc = ((TypeElement) e).getSuperclass();
if (!TypeKind.NONE.equals(sc.getKind()))
r = visitDeclared((DeclaredType) sc, sup);
if (r != null) return r;
}
}
return null;
}
@Override
protected TypeMirror defaultAction(TypeMirror e, TypeElement typeElement) {
return null;
}
private TypeMirror onDeclaredType(DeclaredType t, TypeElement sup) {
// t = sup<...>
if (t.asElement().equals(sup))
return t;
for (TypeMirror i : env.getTypeUtils().directSupertypes(t)) {
TypeMirror r = visitDeclared((DeclaredType) i, sup);
if (r != null) return r;
}
return null;
}
@Override
public TypeMirror visitTypeVariable(TypeVariable t, TypeElement sup) {
// we are checking if T (declared as T extends A&B&C) is assignable to sup.
// so apply bounds recursively.
for (TypeMirror r : ((TypeParameterElement) t.asElement()).getBounds()) {
TypeMirror m = visit(r, sup);
if (m != null) return m;
}
return null;
}
@Override
public TypeMirror visitWildcard(WildcardType type, TypeElement sup) {
// we are checking if T (= ? extends A&B&C) is assignable to sup.
// so apply bounds recursively.
return visit(type.getExtendsBound(), sup);
}
};
/**
* Adapts the string expression into the expression of the given type.
*/
final SimpleTypeVisitor6 simpleValueConverter = new SimpleTypeVisitor6() {
@Override
public JExpression visitPrimitive(PrimitiveType type, JExpression param) {
String kind = type.getKind().toString();
return JExpr.invoke("as" + kind.charAt(0) + kind.substring(1).toLowerCase(Locale.ENGLISH)).arg(param);
}
@Override
public JExpression visitDeclared(DeclaredType type, JExpression param) {
String qn = ((TypeElement) type.asElement()).getQualifiedName().toString();
if (qn.equals("java.lang.String"))
return param; // no conversion needed for string
// return JExpr.invoke("as"+type.getDeclaration().getSimpleName()).arg(param);
throw new UnsupportedOperationException();
}
@Override
protected JExpression defaultAction(TypeMirror e, JExpression jExpression) {
throw new UnsupportedOperationException();
}
};
public TypeMath(ProcessingEnvironment env) {
this.env = env;
}
TypeMirror isCollection(TypeMirror t) {
TypeMirror collectionType = baseClassFinder.visit(t, env.getElementUtils().getTypeElement(Collection.class.getName()));
if (collectionType != null) {
DeclaredType d = (DeclaredType) collectionType;
return d.getTypeArguments().iterator().next();
} else
return null;
}
}