cn.taketoday.core.env.EnumerablePropertySource Maven / Gradle / Ivy
/*
* Original Author -> Harry Yang ([email protected]) https://taketoday.cn
* Copyright © TODAY & 2017 - 2021 All Rights Reserved.
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [http://www.gnu.org/licenses/]
*/
package cn.taketoday.core.env;
import cn.taketoday.util.ObjectUtils;
/**
* A {@link PropertySource} implementation capable of interrogating its
* underlying source object to enumerate all possible property name/value
* pairs. Exposes the {@link #getPropertyNames()} method to allow callers
* to introspect available properties without having to access the underlying
* source object. This also facilitates a more efficient implementation of
* {@link #containsProperty(String)}, in that it can call {@link #getPropertyNames()}
* and iterate through the returned array rather than attempting a call to
* {@link #getProperty(String)} which may be more expensive. Implementations may
* consider caching the result of {@link #getPropertyNames()} to fully exploit this
* performance opportunity.
*
* Most framework-provided {@code PropertySource} implementations are enumerable;
* a counter-example would be {@code JndiPropertySource} where, due to the
* nature of JNDI it is not possible to determine all possible property names at
* any given time; rather it is only possible to try to access a property
* (via {@link #getProperty(String)}) in order to evaluate whether it is present
* or not.
*
* @param the source type
* @author Chris Beams
* @author Juergen Hoeller
* @since 4.0
*/
public abstract class EnumerablePropertySource extends PropertySource {
/**
* Create a new {@code EnumerablePropertySource} with the given name and source object.
*
* @param name the associated name
* @param source the source object
*/
public EnumerablePropertySource(String name, T source) {
super(name, source);
}
/**
* Create a new {@code EnumerablePropertySource} with the given name and with a new
* {@code Object} instance as the underlying source.
*
* @param name the associated name
*/
protected EnumerablePropertySource(String name) {
super(name);
}
/**
* Return whether this {@code PropertySource} contains a property with the given name.
* This implementation checks for the presence of the given name within the
* {@link #getPropertyNames()} array.
*
* @param name the name of the property to find
*/
@Override
public boolean containsProperty(String name) {
return ObjectUtils.containsElement(getPropertyNames(), name);
}
/**
* Return the names of all properties contained by the
* {@linkplain #getSource() source} object (never {@code null}).
*/
public abstract String[] getPropertyNames();
}