com.alibaba.nacos.client.selector.AbstractSelectorWrapper Maven / Gradle / Ivy
/*
* Copyright 1999-2023 Alibaba Group Holding Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.nacos.client.selector;
import com.alibaba.nacos.api.selector.client.Selector;
import com.alibaba.nacos.common.notify.Event;
import java.util.Objects;
/**
* Selector Wrapper.
*
* @param the type of selector
* @param the type of original event
* @param the type of listener callback event
* @author lideyou
*/
public abstract class AbstractSelectorWrapper, E, T extends Event> {
private final S selector;
private final ListenerInvoker listener;
public AbstractSelectorWrapper(S selector, ListenerInvoker listener) {
this.selector = selector;
this.listener = listener;
}
/**
* Check whether the event can be callback.
*
* @param event original event
* @return true if the event can be callback
*/
protected abstract boolean isSelectable(T event);
/**
* Check whether the result can be callback.
*
* @param event select result
* @return true if the result can be callback
*/
protected abstract boolean isCallable(E event);
/**
* Build an event received by the listener.
*
* @param event original event
* @return listener event
*/
protected abstract E buildListenerEvent(T event);
/**
* Notify listener.
*
* @param event original event
*/
public void notifyListener(T event) {
if (!isSelectable(event)) {
return;
}
E newEvent = buildListenerEvent(event);
if (isCallable(newEvent)) {
listener.invoke(newEvent);
}
}
public ListenerInvoker getListener() {
return this.listener;
}
public S getSelector() {
return this.selector;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
AbstractSelectorWrapper that = (AbstractSelectorWrapper) o;
return Objects.equals(selector, that.selector) && Objects.equals(listener, that.listener);
}
@Override
public int hashCode() {
return Objects.hash(selector, listener);
}
}