通过反射创建泛型类的实例

import java.lang.reflect.*;

public class GenericClass<T> {
    private T value;

    public GenericClass() {
    }

    public GenericClass(T value) {
        this.value = value;
    }

    public T getValue() {
        return value;
    }

    public static void main(String[] args) throws Exception {
        // 获取泛型类的Class对象
        Class<?> genericClass = Class.forName("GenericClass");

        // 创建泛型类的实例
        Object instance = genericClass.newInstance();

        // 获取泛型类的构造函数
        Constructor<?> constructor = genericClass.getConstructor(Object.class);

        // 设置泛型类的类型参数
        TypeVariable<?>[] typeParameters = genericClass.getTypeParameters();
        Type[] actualTypeArguments = {String.class}; // 设置类型参数为String
        ParameterizedType parameterizedType = new ParameterizedTypeImpl(genericClass, typeParameters, actualTypeArguments);
        constructor.getGenericParameterTypes()[0] = parameterizedType;

        // 实例化泛型类
        Object genericInstance = constructor.newInstance("Hello, World!");

        // 调用泛型类的方法
        Method getValueMethod = genericClass.getMethod("getValue");
        Object value = getValueMethod.invoke(genericInstance);
        System.out.println(value); // 输出：Hello, World!
    }
}

class ParameterizedTypeImpl implements ParameterizedType {
    private final Class<?> rawType;
    private final Type[] actualTypeArguments;
    private final Type ownerType;

    public ParameterizedTypeImpl(Class<?> rawType, Type[] actualTypeArguments) {
        this(rawType, actualTypeArguments, null);
    }

    public ParameterizedTypeImpl(Class<?> rawType, Type[] actualTypeArguments, Type ownerType) {
        this.rawType = rawType;
        this.actualTypeArguments = actualTypeArguments;
        this.ownerType = ownerType;
    }

    @Override
    public Type[] getActualTypeArguments() {
        return actualTypeArguments;
    }

    @Override
    public Type getRawType() {
        return rawType;
    }

    @Override
    public Type getOwnerType() {
        return ownerType;
    }
}