Class Types

java.lang.Object
com.google.api.client.util.Types

public class Types extends Object
Utilities for working with Java types.
Since:
1.4
  • Constructor Details

    • Types

      private Types()
  • Method Details

    • getSuperParameterizedType

      public static ParameterizedType getSuperParameterizedType(Type type, Class<?> superClass)
      Returns the parameterized type that is or extends the given type that matches the given super class.

      For example, if the input type is HashMap<String,Integer> and the input super class is Map.class, it will return the extended parameterized type Map, but which retains the actual type information from the original HashMap.

      Parameters:
      type - class or parameterized type
      superClass - super class
      Returns:
      matching parameterized type or null
    • isAssignableToOrFrom

      public static boolean isAssignableToOrFrom(Class<?> classToCheck, Class<?> anotherClass)
      Returns whether a class is either assignable to or from another class.
      Parameters:
      classToCheck - class to check
      anotherClass - another class
    • newInstance

      public static <T> T newInstance(Class<T> clazz)
      Creates a new instance of the given class by invoking its default constructor.

      The given class must be public and must have a public default constructor, and must not be an array or an interface or be abstract. If an enclosing class, it must be static.

    • handleExceptionForNewInstance

      private static IllegalArgumentException handleExceptionForNewInstance(Exception e, Class<?> clazz)
    • isArray

      public static boolean isArray(Type type)
      Returns whether the given type is an array.
    • getArrayComponentType

      public static Type getArrayComponentType(Type array)
      Returns the component type of the given array type, assuming isArray(Type).

      Return type will either be class, parameterized type, generic array type, or type variable, but not a wildcard type.

      Throws:
      ClassCastException - if isArray(Type) is false
    • getRawClass

      public static Class<?> getRawClass(ParameterizedType parameterType)
      Returns the raw class for the given parameter type as defined in ParameterizedType.getRawType().
      Parameters:
      parameterType - parameter type
      Returns:
      raw class
    • getBound

      public static Type getBound(WildcardType wildcardType)
      Returns the only bound of the given wildcard type.
      Parameters:
      wildcardType - wildcard type
      Returns:
      only bound or Object.class for none
    • resolveTypeVariable

      public static Type resolveTypeVariable(List<Type> context, TypeVariable<?> typeVariable)
      Resolves the actual type of the given type variable that comes from a field type based on the given context list.

      In case the type variable can be resolved partially, it will return the partially resolved type variable.

      Parameters:
      context - context list, ordering from least specific to most specific type context, for example container class and then its field
      typeVariable - type variable
      Returns:
      resolved or partially resolved actual type (type variable, class, parameterized type, or generic array type, but not wildcard type) or null if unable to resolve at all
    • getRawArrayComponentType

      public static Class<?> getRawArrayComponentType(List<Type> context, Type componentType)
      Returns the raw array component type to use -- for example for the first parameter of Array.newInstance(Class, int) -- for the given component type.
      Parameters:
      context - context list, ordering from least specific to most specific type context, for example container class and then its field
      componentType - array component type or null for Object.class result
      Returns:
      raw array component type
    • getIterableParameter

      public static Type getIterableParameter(Type iterableType)
      Returns the type parameter of Iterable that is assignable from the given iterable type.

      For example, for the type ArrayList<Integer> -- or for a class that extends ArrayList<Integer> -- it will return Integer.

      Parameters:
      iterableType - iterable type (must extend Iterable)
      Returns:
      type parameter, which may be any type
    • getMapValueParameter

      public static Type getMapValueParameter(Type mapType)
      Returns the value type parameter of Map that is assignable from the given map type.

      For example, for the type Map<String, Integer> -- or for a class that extends Map<String, Integer> -- it will return Integer.

      Parameters:
      mapType - map type (must extend Map)
      Returns:
      type parameter, which may be any type
    • getActualParameterAtPosition

      private static Type getActualParameterAtPosition(Type type, Class<?> superClass, int position)
    • iterableOf

      public static <T> Iterable<T> iterableOf(Object value)
      Returns an iterable for an input iterable or array value.

      If the input value extends Iterable, it will just return the input value. Otherwise, it will return an iterable that can handle arrays of primitive and non-primitive component type.

      Parameters:
      value - iterable (extends Iterable) or array value
      Returns:
      iterable
    • toArray

      public static Object toArray(Collection<?> collection, Class<?> componentType)
      Returns a new array of the given component type (possibly a Java primitive) that is a copy of the content of the given collection.
      Parameters:
      collection - collection
      componentType - component type (possibly a Java primitive)
      Returns:
      new array