Java的泛型反射

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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

上文檔DOC，如果父類是一個參數化型別，那麼Type返回的是參數類型的真實類型

 

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

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

package entity;/** * Created by Administrator on 2016/11/27 0027. */public interface BaseDao<T> {   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<User> baseDao1 = new BaseDaoImpl<User>();    }}

 

記錄總結，只有繼承的父類為參數化型別，此時反射的

ParameterizedType 才能拿到參數類型

Java的泛型反射