java8范型测试代码

import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.Collection;
import java.util.List;

public class View
{
    public Collection<String> c;

    public T<Integer> tt;

    public static void main(String[] args) throws NoSuchFieldException, SecurityException
    {
        T<Integer> t = new T();
        TypeVariable<?>[] cs = t.getClass().getTypeParameters();
        for (TypeVariable<?> c : cs)
        {
            // c instanceof ParameterizedType
            // 必须为false,class上不存在实际类型，只存在声明的类型,所以是TypeVariable
            System.out.println(c + " " + (c instanceof ParameterizedType) + "  " + c.getGenericDeclaration());
        }
        Type type = View.class.getDeclaredField("tt").getGenericType();
        printType(type);
        printType(T2.class.getGenericSuperclass());
        type = T.class.getDeclaredField("o").getGenericType();
        printType(type);
        Type types [] = T.class.getMethods()[0].getGenericParameterTypes();
        for(Type ty:types)
            printType(ty);
    }

    static void printType(Type type)
    {
        System.out.println("-----------------------------------------------");
        if (ParameterizedType.class.isAssignableFrom(type.getClass()))
        {
            ParameterizedType pt = (ParameterizedType) type;
            System.out.println("is ParameterizedType...........");
            System.out.println("typeName:" + pt.getTypeName() + "
ownerType:" + pt.getOwnerType() + "
rawType:"
                    + pt.getRawType());
            Type[] typs = pt.getActualTypeArguments();
            for (Type tttt : typs)
                System.out.println(" getActualTypeArguments "+tttt.getTypeName());
        }
        else if (TypeVariable.class.isAssignableFrom(type.getClass()))
        {
            System.out.println("not ParameterizedType  that is TypeVariable");
            TypeVariable t = (TypeVariable) type;
            System.out.println("getGenericDeclaration " + t.getGenericDeclaration());
            System.out.println("name: " + t.getName());
            System.out.println("bounds:" + t.getBounds()[0].getTypeName());
        }
        else if(GenericArrayType.class.isAssignableFrom(type.getClass())) 
        {
            System.out.println("GenericArrayType...");
            GenericArrayType genericArrayType = (GenericArrayType)type;
            printType(genericArrayType.getGenericComponentType());
        }
        else 
        {
            System.out.println("unknow....."+type.getTypeName());
        }
    }

    public static class T2<O> extends T<O>
    {
    }

    public static class T<O>
    {
        O o;

        public void show(List<String>[] pTypeArray, O[] vTypeArray)
        {
        }
    }

}