3.TypeVariable 泛型的类型变量,指的是List、Map中的T,K,V等值,实际的Java类型是TypeVariableImpl(TypeVariable的子类);此外,还可以对类型变量加上extend限定,这样会有类型变量对应的上限; TypeVariable 在TypeVariable接口中,有3个方法,分别为getBounds()、getGenericDecl
function getVariableType(variable) { if (variable instanceof Array) { return "Array"; } else if (variable instanceof Date) { return "Date"; } else if (variable instanceof RegExp) { return "RegExp"; } else { return typeof variable; } } // 示例用法 var var1 = 10; var var2 = ...
TypeVariable is the common superinterface for type variables of kinds. A type variable is created the first time it is needed by a reflective method, as specified in this package. If a type variable t is referenced by a type (i.e, class, interface or annotation type) T, and T is decl...
Assert.that(fv.getGenericType()instanceofTypeVariable,"必须为TypeVariable类型");TypeVariablekeyType=(TypeVariable)fk.getGenericType();TypeVariablevalueType=(TypeVariable)fv.getGenericType();// getName 方法System.out.println(keyType.getName());// KSystem.out.println(valueType.getName());// V...
所以我们无法通过反射API,在运行期获得Type Variable所代表的类型 但是这个特性导致我们在写工具类时会遇到一些困难。比如无法单独通过T来创建实例。如果T是一个非泛型类还好,我们可以通过直接传入类型信息进行一些操作 public static final <T> void foo(List<T> list, Class<T> tClass) ...
Returns the lower bound of this type variable. TypeMirror getUpperBound() Returns the upper bound of this type variable. Methods declared in interface javax.lang.model.type.TypeMirror accept,equals,getAnnotation,getAnnotationMirrors,getAnnotationsByType,getKind,hashCode,toString ...
Type type = declaredField.getGenericType(); if (type instanceof ParameterizedType) { ParameterizedType parameterizedType = (ParameterizedType) type; for (Type actualTypeArgument : parameterizedType.getActualTypeArguments()) { System.out.println(declaredField.getName() + " getActualTypeArguments:" + act...
public interface TypeVariable<D extends GenericDeclaration> extends Type, AnnotatedElement TypeVariable是类型变量的通用超接口。 类型变量在第一次被反射方法需要时创建,如此包中指定的那样。 如果类型变量t由类型(即类,接口或注释类型)T引用,并且T由第n个封闭类T(参见JLS 8.1.2)声明,则t的创建需要分辨率(参见...
and all type arguments of p are created recursively. See TypeVariable for details on the creation process for type variables. Repeated creation of a parameterized type has no effect. Instances of classes that implement this interface must implement an equals() method that equates any two instances...
Type @Deprecated(since="9", forRemoval=true) public interface TypeVariable extends TypeDeprecated, for removal: This API element is subject to removal in a future version. The declarations in this package have been superseded by those in the package jdk.javadoc.doclet. For more information, see...