////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
/**
* Resolves external properties from an
* underlying {@code Properties} object.
*
* @author lkuehne
*/
public final class PropertiesExpander
implements PropertyResolver {
/** The underlying values. */
private final Map<String, String> values;
/**
* Creates a new PropertiesExpander.
* @param properties the underlying properties to use for
* property resolution.
* @throws IllegalArgumentException indicates null was passed
*/
public PropertiesExpander(Properties properties) {
if (properties == null) {
throw new IllegalArgumentException("cannot pass null");
}
values = new HashMap<>(properties.size());
for (Enumeration<?> e = properties.propertyNames(); e.hasMoreElements();) {
final String name = (String) e.nextElement();
values.put(name, properties.getProperty(name));
}
}
@Override
public String resolve(String name) {
return values.get(name);
}
}