If the superclass is a parameterized type, the {@code Type}     * object returned must accurately reflect the actual type     * parameters used in the source code. T

上文档DOC，如果父类是一个参数化类型，那么Type返回的是参数类型的真实类型

 

package entity;import java.lang.reflect.ParameterizedType;import java.lang.reflect.Type;/** * Created by Administrator on 2016/11/27 0027. */public class BaseDaoImpl
     
       implements BaseDao
      
        {    public BaseDaoImpl(){        Type type = getClass().getGenericSuperclass();        Type[] params = ((ParameterizedType)type).getActualTypeArguments();        System.out.println((Class
       
        )params[0]);    }    public T findByid(int id) {        return null;    }}
       
      
     

package entity;/** * Created by Administrator on 2016/11/27 0027. */public class UserDaoImpl extends BaseDaoImpl
     
       {}
     

package entity;/** * Created by Administrator on 2016/11/27 0027. */public interface BaseDao
     
       {   public T findByid(int id);}
     

package entity;import org.junit.Test;/** * Created by Administrator on 2016/11/27 0027. */public class GenericTest {    @Test    public void testGeneric(){        UserDaoImpl baseDao = new UserDaoImpl();        //BaseDaoImpl
     
       baseDao1 = new BaseDaoImpl
      
       ();    }}
      
     

 

记录总结，只有继承的父类为参数化类型，此时反射的

ParameterizedType 才能拿到参数类型