/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.logging.log4j.core.util;
import java.util.HashSet;
import java.util.Set;
/**
* Set-related convenience methods.
*/
public final class SetUtils {
private SetUtils() {
}
/**
* Extracts the Strings from a Set that start with a given prefix.
*
* @param set a Set of Strings (assumed to all be non-{@code null})
* @param prefix the prefix to look for in the string set
* @return an array of the matching strings from the given set
*/
public static String[] prefixSet(final Set<String> set, final String prefix) {
final Set<String> prefixSet = new HashSet<>();
for (final String str : set) {
if (str.startsWith(prefix)) {
prefixSet.add(str);
}
}
return prefixSet.toArray(new String[prefixSet.size()]);
}
}