org.glowroot.agent.util.MaybePatterns Maven / Gradle / Ivy
/*
* Copyright 2018 the original author or authors.
*
* 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 org.glowroot.agent.util;
import java.util.regex.Pattern;
import org.glowroot.agent.shaded.com.google.common.base.Joiner;
import org.glowroot.agent.shaded.org.checkerframework.checker.nullness.qual.Nullable;
public class MaybePatterns {
private MaybePatterns() {}
public static @Nullable Pattern buildPattern(String maybePattern) {
if (maybePattern.startsWith("/") && maybePattern.endsWith("/")) {
// full regex power
return Pattern.compile(maybePattern.substring(1, maybePattern.length() - 1));
}
// limited regex, | and *, should be used whenever possible over full regex since
// . and $ are common in class names
if (maybePattern.contains("|")) {
String[] parts = maybePattern.split("\\|");
for (int i = 0; i < parts.length; i++) {
parts[i] = buildSimplePattern(parts[i]);
}
return Pattern.compile(Joiner.on('|').join(parts));
}
if (maybePattern.contains("*")) {
return Pattern.compile(buildSimplePattern(maybePattern));
}
return null;
}
private static String buildSimplePattern(String part) {
// convert * into .* and quote the rest of the text using \Q...\E
String pattern = "\\Q" + part.replace("*", "\\E.*\\Q") + "\\E";
// strip off unnecessary \\Q\\E in case * appeared at beginning or end of part
return pattern.replace("\\Q\\E", "");
}
}