com.alibaba.nacos.api.selector.AbstractCmdbSelector Maven / Gradle / Ivy
/*
* Copyright 1999-2021 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.api.selector;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.alibaba.nacos.api.selector.context.CmdbContext;
import java.util.List;
import static com.alibaba.nacos.api.common.Constants.Naming.CMDB_CONTEXT_TYPE;
/**
* {@link AbstractCmdbSelector} will provide one default implement of {@link Selector}, users can implement it to use the {@link CmdbContext}.
* And return the result as default subclass of {@link Instance}.
*
* @author chenglu
* @date 2021-07-09 21:29
*/
public abstract class AbstractCmdbSelector implements Selector, CmdbContext, String> {
/**
* the labels expression.
*/
protected String expression;
public String getExpression() {
return expression;
}
public void setExpression(String expression) {
this.expression = expression;
}
@Override
public Selector, CmdbContext, String> parse(String expression) throws NacosException {
this.expression = expression;
doParse(expression);
return this;
}
/**
* The real parse logic implement by sub class.
*
* @param expression expression.
* @throws NacosException parse failed exception.
*/
protected abstract void doParse(String expression) throws NacosException;
@Override
public List select(CmdbContext context) {
return doSelect(context);
}
/**
* The real select implement by subclass.
*
* @param context selector context {@link CmdbContext}.
* @return the select result.
*/
protected abstract List doSelect(CmdbContext context);
@Override
public String getContextType() {
return CMDB_CONTEXT_TYPE;
}
}