How to check method parameter type in annotation processor?

Tovey

This would be easy if pure reflection was used, but the annotation processor world seems to be different. How do I TypeMirrorreturn from getParameterTypes()to String.class?

In my annotation processor, I want to check if the currently accessed method has the form:

public boolean someName(String input)

I can check the original return type, but the Stringparameter creates a problem:

private void processAnnotation(Element method, Messager msg) {
    final MyAnnotation ann = method.getAnnotation(MyAnnotation.class);
    if (method.getKind() != ElementKind.METHOD) {
      error("annotation only for methods", method);
    }
    Set<Modifier> modifiers = method.getModifiers();
    if(!modifiers.contains(Modifier.PUBLIC)) {
      error("annotated Element must be public", method);
    }
    if(modifiers.contains(Modifier.STATIC)) {
      error("annotated Element must not be static", method);
    }
    ExecutableType emeth = (ExecutableType)method.asType();
    if(!emeth.getReturnType().getKind().equals(TypeKind.BOOLEAN)) {
      error("annotated Element must have return type boolean", method);
    }
    if(emeth.getParameterTypes().size() != 1) {
      error("annotated Element must have exactly one parameter", method);
    } else {
      TypeMirror param0 = emeth.getParameterTypes().get(0);
      // TODO: check if param.get(0) is String
    }
}
Radiodef

Elements.getTypeElementDuring processing, we can retrieve it by canonical name.

Types    types = processingEnv.getTypeUtils();
Elements elems = processingEnv.getElementUtils();

TypeMirror param0 = m.getParameterTypes.get(0);
TypeMirror string = elems.getTypeElement("java.lang.String").asType();

boolean isSame = types.isSameType(param0, string);

Such a "class" cannot be obtained because annotation processing operates on partial compilation and we cannot load the class that is being compiled.

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