/*
 * Copyright 1999-2022 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.env;

import java.util.Properties;

abstract class AbstractPropertySource {
    
    /**
     * get property's type.
     * @return name
     */
    abstract SourceType getType();
    
    /**
     * get property, if the value can not be got by the special key, the null will be returned.
     * @param key special key
     * @return value or null
     */
    abstract String getProperty(String key);
    
    /**
     * Tests if the specified object is a key in this propertySource.
     * @param key key – possible key
     * @return true if and only if the specified object is a key in this propertySource, false otherwise.
     */
    abstract boolean containsKey(String key);
    
    /**
     * to properties.
     * @return properties
     */
    abstract Properties asProperties();
    
}
