利用ParameterizedType获取泛型参数类型

https://www.cnblogs.com/baiqiantao/p/5373283.html

GenericsDemo.java

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

//利用ParameterizedType获取java泛型的参数类型

public class GenericsDemo {
    public static void main(String[] args) {
        classTest();
        interfaceTest();
    }
    
    private static void classTest() {
        MySuperClass<Student, String> mySuperClass = new MySuperClass<Student, String>() {
            @Override
            public void onSuccess(Student data) {
            }
        };
        //getClass().getGenericSuperclass()返回表示此 Class 所表示的实体的直接超类的 Type
        ParameterizedType type = (ParameterizedType) mySuperClass.getClass().getGenericSuperclass();
        sysoType(type);
    }
    
    private static void interfaceTest() {
        MyInterface<Student, String> myInterface = new MyInterface<Student, String>() {
            @Override
            public void onSuccess(Student data) {
            }
        };
        ParameterizedType type = (ParameterizedType) myInterface.getClass().getGenericInterfaces()[0];
        sysoType(type);
    }
    
    private static void sysoType(ParameterizedType type) {
        System.out.println(type + "
" + type.getClass());
        
        //返回表示此类型实际类型参数的 Type 对象的数组，泛型的参数可能有多个，我们需要哪个就取哪个
        Type[] targets = type.getActualTypeArguments();
        for (int i = 0; i < targets.length; i++) {
            System.out.println(targets[i] + "
" + targets[i].getClass());
        }
    }
}

MyInterface.java

public interface MyInterface<T, V> {
    void onSuccess(T data);
}

MySuperClass.java

public abstract class MySuperClass<T,V> {
    public abstract void onSuccess(T data);
}

Student.java

public class Student {

}

 GenericsDemo.rar