org.sfm.reflect.ReflectionConstructorDefinitionFactory Maven / Gradle / Ivy

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package org.sfm.reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by aroger on 05/12/14.
 */
public class ReflectionConstructorDefinitionFactory {

    public static  List> extractConstructors(Type target) {
        Class clazz = TypeHelper.toClass(target);
        List> constructorDefinitions = new ArrayList>();

        for(Constructor constructor : clazz.getDeclaredConstructors()) {
            ConstructorDefinition definition = new ConstructorDefinition(constructor, getConstructorParameters(constructor, target));
            constructorDefinitions.add(definition);
        }


        return constructorDefinitions;
    }

    private static ConstructorParameter[] getConstructorParameters(Constructor constructor, Type target) {
        ConstructorParameter[] parameters = new ConstructorParameter[constructor.getParameterTypes().length];
        TypeVariable>[] typeParameters = TypeHelper.toClass(target).getTypeParameters();

        for(int i = 0; i < parameters.length; i++) {
            String name = getName(i, constructor);
            Type paramType = constructor.getGenericParameterTypes()[i];
            Type resolvedParamType = null;
            if (paramType instanceof TypeVariable) {
                TypeVariable tv = (TypeVariable) paramType;
                paramType = constructor.getParameterTypes()[i];
                ParameterizedType pt = (ParameterizedType) target;
                for(int pti = 0; pti < typeParameters.length; pti++) {
                    if (typeParameters[pti].getName().equals(tv.getName())) {
                        resolvedParamType = pt.getActualTypeArguments()[i];
                        break;
                    }
                }
            }
            if (resolvedParamType == null) {
                resolvedParamType = paramType;
            }
            parameters[i] = new ConstructorParameter(name, paramType, resolvedParamType);
        }

        return parameters;
    }

    private static String getName(int i, Constructor constructor) {
        return "arg" + i;
    }
}