Java Code Examples for java.lang.reflect.ParameterizedType

protected boolean isDecoratableList(Field field) {
  if (!List.class.isAssignableFrom(field.getType())) {
    return false;
  }

  // Type erasure in Java isn't complete. Attempt to discover the generic
  // type of the list.
  Type genericType = field.getGenericType();
  if (!(genericType instanceof ParameterizedType)) {
    return false;
  }

  Type listType = ((ParameterizedType) genericType).getActualTypeArguments()[0];

  if (!WebElement.class.equals(listType)) {
    return false;
  }

  return field.getAnnotation(FindBy.class) != null ||
         field.getAnnotation(FindBys.class) != null ||
         field.getAnnotation(FindAll.class) != null;
}
 

public static boolean hasUnresolvableType(Type type) {
    if (type instanceof Class<?>) {
        return false;
    }
    if (type instanceof ParameterizedType) {
        ParameterizedType parameterizedType = (ParameterizedType) type;
        for (Type typeArgument : parameterizedType.getActualTypeArguments()) {
            if (hasUnresolvableType(typeArgument)) {
                return true;
            }
        }
        return false;
    }
    if (type instanceof GenericArrayType) {
        return hasUnresolvableType(((GenericArrayType) type).getGenericComponentType());
    }
    if (type instanceof TypeVariable) {
        return true;
    }
    if (type instanceof WildcardType) {
        return true;
    }
    String className = type == null ? "null" : type.getClass().getName();
    throw new IllegalArgumentException("Expected a Class, ParameterizedType, or " + "GenericArrayType, but <" + type + "> is of type " + className);
}
 

private boolean isTypeMatch(Type type, Type targetType) {
    if (type instanceof Class && targetType instanceof Class) {
        if (((Class) type).isAssignableFrom((Class) targetType)) {
            return true;
        }
    } else if (type instanceof ParameterizedType && targetType instanceof ParameterizedType) {
        ParameterizedType parameterizedType = (ParameterizedType) type;
        ParameterizedType parameterizedTargetType = (ParameterizedType) targetType;
        if (isTypeMatch(parameterizedType.getRawType(), ((ParameterizedType) targetType).getRawType())) {
            Type[] types = parameterizedType.getActualTypeArguments();
            Type[] targetTypes = parameterizedTargetType.getActualTypeArguments();
            if (types == null || targetTypes == null || types.length != targetTypes.length) {
                return false;
            }
            int len = types.length;
            for (int i = 0; i < len; i++) {
                if (!isTypeMatch(types[i], targetTypes[i])) {
                    return false;
                }
            }
            return true;
        }
    }
    return false;
}
 

/**
 * Converts a binding for a {@code Key<TypeLiteral<T>>} to the value {@code TypeLiteral<T>}. It's
 * a bit awkward because we have to pull out the inner type in the type literal.
 */
private <T> BindingImpl<TypeLiteral<T>> createTypeLiteralBinding(
    Key<TypeLiteral<T>> key, Errors errors) throws ErrorsException {
  Type typeLiteralType = key.getTypeLiteral().getType();
  if (!(typeLiteralType instanceof ParameterizedType)) {
    throw errors.cannotInjectRawTypeLiteral().toException();
  }

  ParameterizedType parameterizedType = (ParameterizedType) typeLiteralType;
  Type innerType = parameterizedType.getActualTypeArguments()[0];

  // this is unforunate. We don't support building TypeLiterals for type variable like 'T'. If
  // this proves problematic, we can probably fix TypeLiteral to support type variables
  if (!(innerType instanceof Class)
      && !(innerType instanceof GenericArrayType)
      && !(innerType instanceof ParameterizedType)) {
    throw errors.cannotInjectTypeLiteralOf(innerType).toException();
  }

  @SuppressWarnings("unchecked") // by definition, innerType == T, so this is safe
  TypeLiteral<T> value = (TypeLiteral<T>) TypeLiteral.get(innerType);
  InternalFactory<TypeLiteral<T>> factory = new ConstantFactory<TypeLiteral<T>>(
      Initializables.of(value));
  return new InstanceBindingImpl<TypeLiteral<T>>(this, key, SourceProvider.UNKNOWN_SOURCE,
      factory, ImmutableSet.<InjectionPoint>of(), value);
}
 

public static Class<?> getGenericClass(Class<?> cls, int i) {
    try {
        ParameterizedType parameterizedType = ((ParameterizedType) cls.getGenericInterfaces()[0]);
        Object genericClass = parameterizedType.getActualTypeArguments()[i];
        if (genericClass instanceof ParameterizedType) { // 处理多级泛型
            return (Class<?>) ((ParameterizedType) genericClass).getRawType();
        } else if (genericClass instanceof GenericArrayType) { // 处理数组泛型
            return (Class<?>) ((GenericArrayType) genericClass).getGenericComponentType();
        } else if (genericClass != null) {
            return (Class<?>) genericClass;
        }
    } catch (Throwable e) {
    }
    if (cls.getSuperclass() != null) {
        return getGenericClass(cls.getSuperclass(), i);
    } else {
        throw new IllegalArgumentException(cls.getName() + " generic type undefined!");
    }
}
 

@SuppressWarnings({"rawtypes", "unchecked"})
@Override
public void writeTo(Optional<?> entity,
                    Class<?> type,
                    Type genericType,
                    Annotation[] annotations,
                    MediaType mediaType,
                    MultivaluedMap<String, Object> httpHeaders,
                    OutputStream entityStream)
        throws IOException {
    if (!entity.isPresent()) {
        throw new NotFoundException();
    }

    final Type innerGenericType = (genericType instanceof ParameterizedType) ?
        ((ParameterizedType) genericType).getActualTypeArguments()[0] : entity.get().getClass();

    MessageBodyWriter writer = mbw.get().getMessageBodyWriter(entity.get().getClass(),
        innerGenericType, annotations, mediaType);
    writer.writeTo(entity.get(), entity.get().getClass(),
        innerGenericType, annotations, mediaType, httpHeaders, entityStream);
}
 

/**
 * 通过反射, 获得Class定义中声明的父类的泛型参数的类型.
 * 如无法找到, 返回Object.class.
 * 
 * 如public UserDao extends HibernateDao<User,Long>
 * 
 * @param clazz clazz The class to introspect
 * @param index the Index of the generic ddeclaration,start from 0.
 * @return the index generic declaration, or Object.class if cannot be determined
 */
@SuppressWarnings("rawtypes")
public static Class getClassGenricType(final Class clazz, final int index) {

	Type genType = clazz.getGenericSuperclass();

	if (!(genType instanceof ParameterizedType)) {
		logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");
		return Object.class;
	}

	Type[] params = ((ParameterizedType) genType).getActualTypeArguments();

	if ((index >= params.length) || (index < 0)) {
		logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: "
				+ params.length);
		return Object.class;
	}
	if (!(params[index] instanceof Class)) {
		logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");
		return Object.class;
	}

	return (Class) params[index];
}
 

@SuppressWarnings("unchecked")
public void addExceptionMapper(ObjectFactory<ProviderDescriptor> exceptionMapperFactory) {
    for (Type type : exceptionMapperFactory.getObjectModel().getObjectClass().getGenericInterfaces()) {
        if (type instanceof ParameterizedType) {
            ParameterizedType parameterizedType = (ParameterizedType)type;
            if (ExceptionMapper.class == parameterizedType.getRawType()) {
                Type[] typeArguments = parameterizedType.getActualTypeArguments();
                if (typeArguments.length != 1) {
                    throw new RuntimeException("Unable strong determine actual type argument");
                }
                Class<? extends Throwable> errorType = (Class<? extends Throwable>)typeArguments[0];
                if (exceptionMappers.putIfAbsent(errorType, exceptionMapperFactory) != null) {
                    throw new DuplicateProviderException(String.format("ExceptionMapper for exception %s already registered", errorType));
                }
            }
        }
    }
}
 

private int getPriority(final EventMapping mapping, final Type type) {
    if (mapping.priority() != EventMapping.DEFAULT_PRIORITY_VALUE) {
        return mapping.priority();
    }

    if (type == Event.class) {
        return EventMapping.DEFAULT_PRIORITY_FOR_EVENT_IFACE;
    }

    if (type instanceof Class) {
        return ((Class<?>) type).isInterface()
               ? EventMapping.DEFAULT_PRIORITY_FOR_IFACE
               : EventMapping.DEFAULT_PRIORITY_FOR_CLASS;
    }

    if (type instanceof ParameterizedType) {
        return EventMapping.DEFAULT_PRIORITY_FOR_PARAMETRIZED_TYPE;
    }

    throw new IllegalStateException();
}
 

protected static Pair<String, Class<? extends Object>> getChildInfo(Class target) {
    Field[] declaredFields = target.getDeclaredFields();
    for (Field field : declaredFields) {
        final Class<?> type = field.getType();
        if (type.isAssignableFrom(Collection.class)) {
            final ParameterizedType parameterizedType = (ParameterizedType) field.getGenericType();
            String clazz = null;
            try {
                clazz = parameterizedType.getActualTypeArguments()[0].getTypeName();
                return new Pair(field.getName(), Class.forName(clazz));
            } catch (ClassNotFoundException ex) {
                throw new IllegalStateException("Cannot find class " + clazz, ex);
            }
        }
    }
    return null;
}
 

@SuppressWarnings("unchecked")
public <T> T getListWith(ObjectMapper mapper, TypeReference<T> t) throws IOException {
  if (opaque != null) {
    Type c = t.getType();
    if (c instanceof ParameterizedType) {
      c = ((ParameterizedType)c).getRawType();
    }
    if ( c.equals(opaque.getClass())) {
      return (T) opaque;
    } else {
      throw new IOException(String.format("Attempted to retrieve a list with type of %s.  However, the JSON " +
        "options carried an opaque value of type %s.", t.getType(), opaque.getClass().getName()));
    }
  }
  if (root == null) {
    return null;
  }
  return mapper.treeAsTokens(root).readValueAs(t);
}
 

public static Type canonicalize(Type type) {
    if (type instanceof Class) {
        Class<?> c = (Class) type;
        return c.isArray() ? new GenericArrayTypeImpl(C$Gson$Types.canonicalize(c.getComponentType())) : c;
    } else if (type instanceof ParameterizedType) {
        ParameterizedType p = (ParameterizedType) type;
        return new ParameterizedTypeImpl(p.getOwnerType(), p.getRawType(), p.getActualTypeArguments());
    } else if (type instanceof GenericArrayType) {
        return new GenericArrayTypeImpl(((GenericArrayType) type).getGenericComponentType());
    } else {
        if (!(type instanceof WildcardType)) {
            return type;
        }
        WildcardType w = (WildcardType) type;
        return new WildcardTypeImpl(w.getUpperBounds(), w.getLowerBounds());
    }
}
 

private <T> T deserializeObject(Object object, Type type) throws JSONException {
    if (JSONObject.NULL == object) {
        return null;
    }
    if (!(object instanceof JSONObject)) {
        return (T) object;
    }
    JSONObject jsonObject = (JSONObject) object;
    if (JSONPojo.class.equals(type)) {
        JSONPojo result = new JSONPojo();
        result.pojoInt = jsonObject.getInt("pojoInt");
        result.pojoDouble = jsonObject.getDouble("pojoDouble");
        result.pojoStr = jsonObject.getString("pojoStr");
        result.pojoList = deserializeArray(jsonObject.getJSONArray("pojoList"), Integer.class);
        return (T) result;
    } else if (type instanceof ParameterizedType && Map.class
            .equals(((ParameterizedType) type).getRawType())) {
        return (T) deserializeMap(jsonObject, ((ParameterizedType) type).getActualTypeArguments()[1]);
    }
    throw new JSONException("Unable to parse object " + object);
}
 

private Type getOptionalGenericType(Type type) {
    if (Optional.class.equals(type)) {
        return Object.class;
    }

    if (!(type instanceof ParameterizedType)) {
        return null;
    }

    ParameterizedType parameterizedType = (ParameterizedType) type;
    if (Optional.class.equals(parameterizedType.getRawType())) {
        return parameterizedType.getActualTypeArguments()[0];
    }

    return null;
}
 

@Override
public List<GraphQLArgument> call(@Nullable Field field, Method method, Class declaringClass, Annotation annotation) {
    // if same annotation is detected on both field and getter we fail. Only one annotation is allowed. We can talk about having precedence logic later.
    if (method.isAnnotationPresent(annotation.annotationType()) && field != null && field.isAnnotationPresent(annotation.annotationType())) {
        throw new IllegalArgumentException("Conflict: GraphQL Annotations can't be added to both field and getter. Pick one for "+
                                                   annotation.annotationType() + " on " + field.getName() + " and " + method.getName());
    }

    Type returnType = GenericTypeReflector.getExactReturnType(method, declaringClass);
    if (returnType instanceof ParameterizedType) {
        ParameterizedType parameterizedType = (ParameterizedType) returnType;

        Type containerType = parameterizedType.getRawType();
        if (Collection.class.isAssignableFrom((Class) containerType)) {
            List<GraphQLArgument> arguments = new ArrayList<>();
            arguments.add(newArgument().name(GlitrForwardPagingArguments.FIRST).type(GraphQLInt).build());
            arguments.add(newArgument().name(GlitrForwardPagingArguments.AFTER).type(GraphQLString).build());
            return arguments;
        }
    }

    return new ArrayList<>();
}
 

@Override
public TypeBuilder name(Type type) {

    if ( type instanceof Class) {
        return name((Class<?>)type);
    } else {
        if ( type instanceof ParameterizedType ) {

            ParameterizedType pt = (ParameterizedType) type;
            if ( pt.getRawType() instanceof Class && Collection.class.isAssignableFrom((Class)pt.getRawType()) &&  pt.getActualTypeArguments().length == 1) {

                Class<?> cls = (Class<?>) pt.getActualTypeArguments()[0];
                TypeBuilder builder = name(cls);
                return TypeBuilder.arrayOf(builder);
            } else {
                throw new IllegalArgumentException("can't parse type " + pt);
            }
        } else {

            throw new IllegalArgumentException("can't parse type " + type);
        }
    }
}
 

@Override
public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
    Class<?> rawType = getRawType(type);
    boolean isMono = rawType == Mono.class;
    if (rawType != Flux.class && !isMono) {

        if (rawType == Response.class) {
            Type publisherType = getParameterUpperBound(0, (ParameterizedType) type);
            Class<?> rawPublisherType = getRawType(publisherType);
            isMono = rawPublisherType == Mono.class;
            boolean isFlux = rawPublisherType == Flux.class;

            if (isMono || isFlux) {
                return EMPTY_CONVERTER;
            }
        }

        return null;
    }
    return EMPTY_CONVERTER;
}
 

public static Type processGenericTypeIfNeeded(Class<?> serviceCls, Class<?> paramCls, Type type) {

        if (type instanceof TypeVariable) {
            type = InjectionUtils.getSuperType(serviceCls, (TypeVariable<?>)type);
        } else if (type instanceof ParameterizedType) {
            ParameterizedType pt = (ParameterizedType)type;
            if (pt.getActualTypeArguments()[0] instanceof TypeVariable
                && isSupportedCollectionOrArray(getRawType(pt))) {
                TypeVariable<?> typeVar = (TypeVariable<?>)pt.getActualTypeArguments()[0];
                Type theType = InjectionUtils.getSuperType(serviceCls, typeVar);
                if (theType instanceof Class) {
                    type = new ParameterizedCollectionType((Class<?>)theType);
                } else {
                    type = processGenericTypeIfNeeded(serviceCls, paramCls, theType);
                    type = new ParameterizedCollectionType(type);
                }
            }
        }

        if (type == null || type == Object.class) {
            type = paramCls;
        }
        return type;

    }
 

private void generateControl(Class clazz) {
    Type type = clazz.getGenericSuperclass(); //获得带有泛型的父类
    if (type instanceof ParameterizedType) {
        ParameterizedType p = (ParameterizedType) type; //获得参数化类型，即泛型
        Type[] arrayClasses = p.getActualTypeArguments(); //获取参数化类型的数组，泛型可能有多个

        for (Type item : arrayClasses) {
            if (item instanceof Class) {
                Class<T> tClass = (Class<T>) item;

                if (tClass.equals(BaseControl.class) || (tClass.getSuperclass() != null &&
                        tClass.getSuperclass().equals(BaseControl.class))) {
                    messageProxy = new MessageProxy(mHandler);
                    mControl = ControlFactory.getControlInstance(tClass, messageProxy);
                    mModel = new ModelMap();
                    mControl.setModel(mModel);
                    return;
                }
            }
        }
    }
}
 

public Type onParameterizdType(ParameterizedType p, BinderArg args) {
    Type[] params = p.getActualTypeArguments();

    boolean different = false;
    for (int i = 0; i < params.length; i++) {
        Type t = params[i];
        params[i] = visit(t, args);
        different |= t != params[i];
    }

    Type newOwner = p.getOwnerType();
    if (newOwner != null) {
        newOwner = visit(newOwner, args);
    }
    different |= p.getOwnerType() != newOwner;

    if (!different) {
        return p;
    }

    return new ParameterizedTypeImpl((Class<?>) p.getRawType(), params, newOwner);
}
 

public Type onParameterizdType(ParameterizedType p, BinderArg args) {
    Type[] params = p.getActualTypeArguments();

    boolean different = false;
    for (int i = 0; i < params.length; i++) {
        Type t = params[i];
        params[i] = visit(t, args);
        different |= t != params[i];
    }

    Type newOwner = p.getOwnerType();
    if (newOwner != null) {
        newOwner = visit(newOwner, args);
    }
    different |= p.getOwnerType() != newOwner;

    if (!different) {
        return p;
    }

    return new ParameterizedTypeImpl((Class<?>) p.getRawType(), params, newOwner);
}
 

/**
 * Returns the generic type at the given position for the given interface.
 *
 * @param instance the implementing instance
 * @param iface    the generic interface
 * @param position the generic position
 * @return the generic type at the given position
 */
public static Type getGenericInterfaceType(Object instance, Class<?> iface, int position) {
  Class<?> type = instance.getClass();
  while (type != Object.class) {
    for (Type genericType : type.getGenericInterfaces()) {
      if (genericType instanceof ParameterizedType) {
        ParameterizedType parameterizedType = (ParameterizedType) genericType;
        if (parameterizedType.getRawType() == iface) {
          return parameterizedType.getActualTypeArguments()[position];
        }
      }
    }
    type = type.getSuperclass();
  }
  return null;
}
 

/**
 * 提取实际的泛型参数数组.
 *
 * @param parameterizedType
 *            the parameterized type
 * @return 如果 <code>parameterizedType</code> 是null,抛出 {@link NullPointerException}<br>
 *         如果 <code>parameterizedType</code> 没有实际的泛型参数 {@link ParameterizedType#getActualTypeArguments()},抛出
 *         {@link NullPointerException}<br>
 * @see java.lang.reflect.ParameterizedType#getActualTypeArguments()
 * @since 1.1.1
 */
private static Class<?>[] extractActualTypeArgumentClassArray(ParameterizedType parameterizedType){
    Validate.notNull(parameterizedType, "parameterizedType can't be null/empty!");
    if (LOGGER.isTraceEnabled()){
        LOGGER.trace("parameterizedType info:[{}]", parameterizedType);
    }

    //---------------------------------------------------------------
    Type[] actualTypeArguments = parameterizedType.getActualTypeArguments();
    Validate.notNull(actualTypeArguments, "actualTypeArguments can't be null/empty!");

    //---------------------------------------------------------------

    if (LOGGER.isTraceEnabled()){
        LOGGER.trace("actualTypeArguments:[{}]", ConvertUtil.toString(actualTypeArguments, ToStringConfig.DEFAULT_CONNECTOR));
    }
    return convert(actualTypeArguments, Class[].class);
}
 

/**
 * Resolves all type variables in {@code type} and all downstream types and returns a
 * corresponding type with type variables resolved.
 */


public Type resolveType(Type type) {
  checkNotNull(type);
  if (type instanceof TypeVariable) {
    return typeTable.resolve((TypeVariable<?>) type);
  } else if (type instanceof ParameterizedType) {
    return resolveParameterizedType((ParameterizedType) type);
  } else if (type instanceof GenericArrayType) {
    return resolveGenericArrayType((GenericArrayType) type);
  } else if (type instanceof WildcardType) {
    return resolveWildcardType((WildcardType) type);
  } else {
    // if Class<?>, no resolution needed, we are done.
    return type;
  }
}
 

private Class<?> resolveClass(Type type, Class<?> subType) {
    if (type instanceof Class) {
        return (Class<?>) type;
    } else if (type instanceof ParameterizedType) {
        return resolveClass(((ParameterizedType) type).getRawType(), subType);
    } else if (type instanceof GenericArrayType) {
        GenericArrayType gat = (GenericArrayType) type;
        Class<?> component = resolveClass(gat.getGenericComponentType(), subType);
        return Array.newInstance(component, 0).getClass();
    } else if (type instanceof TypeVariable<?>) {
        TypeVariable<?> variable = (TypeVariable<?>) type;
        Type resolvedType = getTypeVariableMap(subType).get(variable);
        return (resolvedType == null) ? resolveClass(resolveBound(variable), subType)
                : resolveClass(resolvedType, subType);
    } else if (type instanceof WildcardType) {
        WildcardType wcType = (WildcardType) type;
        Type[] bounds = wcType.getLowerBounds().length == 0 ? wcType.getUpperBounds()
                : wcType.getLowerBounds();
        return resolveClass(bounds[0], subType);
    }
    // there are no more types in a standard JDK
    throw new IllegalArgumentException("Unknown type: " + type);
}
 

private static Class<?> toRawType(Type type) {
    if (type instanceof Class) {
        return (Class<?>) type;
    }
    if (type instanceof ParameterizedType) {
        return (Class<?>) ((ParameterizedType) type).getRawType();
    }

    throw new IllegalArgumentException("Unsupported or invalid parameter type: " + type);
}
 

@Override
public void check(Field field) throws CodeCheckException {
	Class<?> type = field.getType();
	if (!Collection.class.isAssignableFrom(type) && !Map.class.isAssignableFrom(type)) {
		assertFieldValid(field);
	} else {
		checkFieldCollectionOrMap(field, (ParameterizedType) field.getGenericType());
	}
}
 

/**
 * <p> Tries to determine the type arguments of a class/interface based on a
 * super parameterized type's type arguments. This method is the inverse of
 * {@link #getTypeArguments(Type, Class)} which gets a class/interface's
 * type arguments based on a subtype. It is far more limited in determining
 * the type arguments for the subject class's type variables in that it can
 * only determine those parameters that map from the subject {@link Class}
 * object to the supertype. </p> <p> Example: {@link java.util.TreeSet
 * TreeSet} sets its parameter as the parameter for
 * {@link java.util.NavigableSet NavigableSet}, which in turn sets the
 * parameter of {@link java.util.SortedSet}, which in turn sets the
 * parameter of {@link Set}, which in turn sets the parameter of
 * {@link java.util.Collection}, which in turn sets the parameter of
 * {@link java.lang.Iterable}. Since <code>TreeSet</code>'s parameter maps
 * (indirectly) to <code>Iterable</code>'s parameter, it will be able to
 * determine that based on the super type <code>Iterable<? extends
 * Map<Integer,? extends Collection<?>>></code>, the parameter of
 * <code>TreeSet</code> is <code>? extends Map<Integer,? extends
 * Collection<?>></code>. </p>
 *
 * @param cls the class whose type parameters are to be determined
 * @param superType the super type from which <code>cls</code>'s type
 * arguments are to be determined
 * @return a map of the type assignments that could be determined for the
 * type variables in each type in the inheritance hierarchy from
 * <code>type</code> to <code>toClass</code> inclusive.
 */
public static Map<TypeVariable<?>, Type> determineTypeArguments(Class<?> cls,
        ParameterizedType superType) {
    Class<?> superClass = getRawType(superType);

    // compatibility check
    if (!isAssignable(cls, superClass)) {
        return null;
    }

    if (cls.equals(superClass)) {
        return getTypeArguments(superType, superClass, null);
    }

    // get the next class in the inheritance hierarchy
    Type midType = getClosestParentType(cls, superClass);

    // can only be a class or a parameterized type
    if (midType instanceof Class<?>) {
        return determineTypeArguments((Class<?>) midType, superType);
    }

    ParameterizedType midParameterizedType = (ParameterizedType) midType;
    Class<?> midClass = getRawType(midParameterizedType);
    // get the type variables of the mid class that map to the type
    // arguments of the super class
    Map<TypeVariable<?>, Type> typeVarAssigns = determineTypeArguments(midClass, superType);
    // map the arguments of the mid type to the class type variables
    mapTypeVariablesToArguments(cls, midParameterizedType, typeVarAssigns);

    return typeVarAssigns;
}
 

/**
 * <p> Closest parent type? Closest to what? The closest parent type to the
 * super class specified by <code>superClass</code>. </p>
 *
 * @param cls the class in question
 * @param superClass the super class
 * @return the closes parent type
 */
private static Type getClosestParentType(Class<?> cls, Class<?> superClass) {
    // only look at the interfaces if the super class is also an interface
    if (superClass.isInterface()) {
        // get the generic interfaces of the subject class
        Type[] interfaceTypes = cls.getGenericInterfaces();
        // will hold the best generic interface match found
        Type genericInterface = null;

        // find the interface closest to the super class
        for (Type midType : interfaceTypes) {
            Class<?> midClass = null;

            if (midType instanceof ParameterizedType) {
                midClass = getRawType((ParameterizedType) midType);
            } else if (midType instanceof Class<?>) {
                midClass = (Class<?>) midType;
            } else {
                throw new IllegalStateException("Unexpected generic"
                        + " interface type found: " + midType);
            }

            // check if this interface is further up the inheritance chain
            // than the previously found match
            if (isAssignable(midClass, superClass)
                    && isAssignable(genericInterface, (Type) midClass)) {
                genericInterface = midType;
            }
        }

        // found a match?
        if (genericInterface != null) {
            return genericInterface;
        }
    }

    // none of the interfaces were descendants of the target class, so the
    // super class has to be one, instead
    return cls.getGenericSuperclass();
}
 

/**
 * If type is a parameterized type, searches the given type variable in the list
 * of declared type variables, and then returns the corresponding actual type.
 * Returns null if the type variable is not defined by type.
 */
private static Type matchTypeVariable(Type type, TypeVariable<?> variable) {
  if (type instanceof ParameterizedType) {
    Class<?> rawInterfaceType = getRawType(type);
    TypeVariable<?>[] typeParameters = rawInterfaceType.getTypeParameters();
    for (int i = 0; i < typeParameters.length; i++) {
      if (variable.equals(typeParameters[i])) {
        return ((ParameterizedType) type).getActualTypeArguments()[i];
      }
    }
  }
  return null;
}