The types of elements in annotation processor are not from javax.lang.model.element package

Question

I have annotation parser, inside it i use this piece of code:

        Set annotatedElements = roundEnv.getElementsAnnotatedWith(annotation);
        for (Element el : annotatedElements) {
            try {
               TypeElement targetClass = (TypeElement) el;
               List fields = getFields(targetClass);
               for (VariableElement e : fields) {
                   String type = getType(e);
                   String name = getVariableName(e));                              
               }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

And methods:

public List getFields(TypeElement targetClass) {
    List enclosedElements = targetClass.getEnclosedElements();
    List fields = new ArrayList<>(enclosedElements.size());
    for (Element field : enclosedElements) {
        if (field.getKind() == ElementKind.FIELD && !field.getModifiers().contains(Modifier.STATIC)) {
            fields.add((VariableElement) field);
        }
    }
    return fields;
}


public String getType(VariableElement variable) {
    if (variable instanceof PrimitiveType) {
        return variable.asType().toString();
    }
    return ((DeclaredType) variable.asType()).asElement().toString();
}

The first methods gets all non static fields inside the class.

And the second method should get type of the variable as String, so "String", "boolean", "MyObject" and so on. However when the field is type of boolean i get this error:

com.sun.tools.javac.code.Type$JCPrimitiveType cannot be cast to javax.lang.model.type.DeclaredType

I expected boolean and other primitive types to be type of PrimitiveType however for some reason it is com.sun.tools.javac.code.Type$JCPrimitiveType

Same, when i try to get all getters from the class:

public List getGetterMethods(TypeElement targetClass) {
    List enclosedElements = targetClass.getEnclosedElements();
    List fields = new ArrayList<>(enclosedElements.size());
    for (Element field : enclosedElements) {
        if (field.getKind() == ElementKind.METHOD &&
                !field.getModifiers().contains(Modifier.STATIC) &&
                (field.getSimpleName().toString().startsWith("get") || field.getSimpleName().toString().startsWith("is"))) {
            fields.add((VariableElement) field);
        }
    }
    return fields;
}

I get error:

java.lang.ClassCastException: com.sun.tools.javac.code.Symbol$MethodSymbol cannot be cast to javax.lang.model.element.VariableElement

It seems com.sun.tools.javac.code package should be part of the JDK however I cannot find it anyhwere. And thus i cannot import it and maybe make some adjustments.

WHat is the best way to deal with this error? Even if i could import the package, it seems the types of it are weirdly assigned, as i would expect types of it to be part of javax.lang.model.element package.

Thanks for help!

//edit

according to docs :

public static class Type.JCPrimitiveType
extends Type
implements PrimitiveType

so the Type.JCPrimitiveType should be instanceOf PrimitiveType, yet the if does not hold true when executing for some reason

user_11866308 · Answer

Element.getEnclosedElements() will retrieve all Elements. Instead try changing your getGetterMethods(TypeElement) to something like:

...
import javax.lang.model.util.ElementFilter;
...
public List getGetterMethods(TypeElement targetClass) {
    List fields =
        ElementFilter.fieldsIn(Collections.singleton(targetClass)).stream()
        .filter(t -> (! t.getModifiers().contains(Modifier.STATIC)))
        .filter(t -> (t.getSimpleName().toString().startsWith("get")
                      || t.getSimpleName().toString().startsWith("is")))
        .collect(Collectors.toList());

    return fields;
}

(Similar change to your getFields() method without the filtering.)

The types of elements in annotation processor are not from javax.lang.model.element package

1 Answers