认识达内从这里开始

简单来说，Class实现了Type接口。

Type源码定义：

package java.lang.reflect;

/**

* Type is the common superinterface for all types in the Java

* programming language. These include raw types, parameterized types,

* array types, type variables and primitive types.

*

* @since 1.5

*/

public interface Type {

}

Class实现了Type接口：

public final class Class implements java.io.Serializable,

java.lang.reflect.GenericDeclaration,

java.lang.reflect.Type,

java.lang.reflect.AnnotatedElement {

}

类型的概念

“类型”刻划了一组值及其上可施行的操作，可理解为“值集”和“操作集”构成的二元组。

“类型的概念”与“值的概念”相对立，前者是程序中的概念，后者则是程序运行时的概念，两者通过“标识值”的语言成分(例如，变量、表达式等)联系起来。

比如变量v为具体类型T，类型T所刻划的值集为{v1，v2，…vn，…}，则变量v运行时能取且只能取某个vi为值。由此可见，“类型”规定了具有该类型的变量或表达式的取值范围。

2、获取Java泛型参数类型

package com.rk.test;

import java.lang.reflect.ParameterizedType;

import java.lang.reflect.Type;

import org.junit.Test;

public class ReflectTest

{

@Test

public void test()

{

Type type = Tiger.class.getGenericSuperclass();//com.rk.test.BaseAnimal

ParameterizedType pt = (ParameterizedType) type;//com.rk.test.BaseAnimal

Type[] types = pt.getActualTypeArguments();//[class com.rk.test.Cat]

Type rawType = pt.getRawType();//class com.rk.test.BaseAnimal

Type ownerType = pt.getOwnerType();//null

Class clazz = (Class) types[0];//class com.rk.test.Cat

String className = clazz.getName();//com.rk.test.Cat

String simpleName = clazz.getSimpleName();//Cat

System.out.println(className);

System.out.println(simpleName);

}

}

class BaseAnimal

{

}

class Cat

{

}

class Tiger extends BaseAnimal

{

}

3、ParameterizedType

package java.lang.reflect;

/**

* ParameterizedType represents a parameterized type such as

* Collection.

*

*

Instances of classes that implement this interface must implement

* an equals() method that equates any two instances that share the

* same generic type declaration and have equal type parameters.

*

* @since 1.5

*/

public interface ParameterizedType extends Type {

/**

* Returns an array of {@code Type} objects representing the actual type

* arguments to this type.

*

*

Note that in some cases, the returned array be empty. This can occur

* if this type represents a non-parameterized type nested within

* a parameterized type.

*

*/

Type[] getActualTypeArguments();

/**

* Returns the {@code Type} object representing the class or interface

* that declared this type.

*/

Type getRawType();

/**

* Returns a {@code Type} object representing the type that this type

* is a member of. For example, if this type is {@code O.I},

* return a representation of {@code O}.

*

*

If this type is a top-level type, {@code null} is returned.

*

*/

Type getOwnerType();

}