java - 子类不能调用父类的public方法

Question

我有一个名为 Foo 的抽象类，它实现了 Bar 接口(interface)。 Foo 确实为 Bar 方法提供了 public 实现。

现在我有了扩展 Foo 的 FooBar 类。奇怪的是，我现在必须在 FooBar 中实现 Bar 接口(interface)。接下来让我感到奇怪的是，我无法在 FooBar 中调用 super.barMethod()，因为这会引发以下错误:

Cannot directly invoke the abstract method barMethod for the type Bar

更奇怪的是，Bar 有 10 多个方法，但我只需在 FooBar 中实现 2 个。

有什么想法为什么会发生这种情况以及如何解决它吗？

<小时/>

代码:

Foo 类:

public abstract class PersistentEnumUserType<T extends PersistentEnum>
        implements UserType {

    /** The persistent enum type */
    private Class<T> persistentClass;

    @SuppressWarnings("unchecked")
    public PersistentEnumUserType() {
        this.persistentClass = (Class<T>) findParameterizedType(getClass())
                .getActualTypeArguments()[0];
    }

    private ParameterizedType findParameterizedType(
            @SuppressWarnings("rawtypes") Class clazz) {
        if (clazz == null) {
            return null;
        }

        Type type = clazz.getGenericSuperclass();
        if (type instanceof ParameterizedType) {
            return (ParameterizedType) type;
        }
        return findParameterizedType(clazz.getSuperclass());
    }

    public Object assemble(Serializable cached, Object owner)
            throws HibernateException {
        return cached;
    }

    public Object deepCopy(Object value) throws HibernateException {
        return value;
    }

    public Serializable disassemble(Object value) throws HibernateException {
        return (Serializable) value;
    }

    public boolean equals(Object x, Object y) throws HibernateException {
        return x == y;
    }

    public int hashCode(Object x) throws HibernateException {
        return x == null ? 0 : x.hashCode();
    }

    public boolean isMutable() {
        return false;
    }

    public Object nullSafeGet(ResultSet rs, String[] names,
            SessionImplementor session, Object owner)
            throws HibernateException, SQLException {
        int id = rs.getInt(names[0]);
        if (rs.wasNull()) {
            return null;
        }
        for (PersistentEnum value : returnedClass().getEnumConstants()) {
            if (id == value.getCode()) {
                return value;
            }
        }
        throw new IllegalStateException("Unknown "
                + returnedClass().getSimpleName() + " id");
    }

    public void nullSafeSet(PreparedStatement st, Object value, int index,
            SessionImplementor session) throws HibernateException, SQLException {
        if (value == null) {
            st.setNull(index, Types.INTEGER);
        } else {
            st.setInt(index, ((PersistentEnum) value).getCode());
        }
    }

    public Object replace(Object original, Object target, Object owner)
            throws HibernateException {
        return original;
    }

    public Class<T> returnedClass() {
        return persistentClass;
    }

    public int[] sqlTypes() {
        return new int[] { Types.INTEGER };
    }

}

Bar界面:

public interface UserType {

    int[] sqlTypes();

    Class returnedClass();

    boolean equals(Object x, Object y) throws HibernateException;

    int hashCode(Object x) throws HibernateException;

    Object nullSafeGet(ResultSet rs, String[] names, SharedSessionContractImplementor session, Object owner) throws HibernateException, SQLException;

    void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor session) throws HibernateException, SQLException;

    Object deepCopy(Object value) throws HibernateException;

    boolean isMutable();

    Serializable disassemble(Object value) throws HibernateException;

    Object assemble(Serializable cached, Object owner) throws HibernateException;

    Object replace(Object original, Object target, Object owner) throws HibernateException;
}

当前 FooBar 类应实现 2 个方法(nullSafeGet 和 nullSafeSet):

public class FileTransferJobUserType extends
        PersistentEnumUserType<FileTransferJob> {

}

Answer 1

nullSafeGet(...) 和 nullSafeSet(...) 未在抽象类中实现，而是重载:它们不具有相同的参数类型，例如SessionImplementor 而不是 SharedSessionContractImplementor