feign.utils.ExceptionUtils Maven / Gradle / Ivy
/*
* Copyright 2012-2023 The Feign 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 feign.utils;
import java.util.HashSet;
import java.util.Set;
public class ExceptionUtils {
/**
* Introspects the {@link Throwable} to obtain the root cause.
*
*
* This method walks through the exception chain to the last element, "root" of the tree, using
* {@link Throwable#getCause()}, and returns that exception.
*
* @param throwable the throwable to get the root cause for, may be null
* @return the root cause of the {@link Throwable}, {@code null} if null throwable input
*/
public static Throwable getRootCause(Throwable throwable) {
if (throwable == null) {
return null;
}
Throwable rootCause = throwable;
// this is to avoid infinite loops for recursive cases
final Set seenThrowables = new HashSet<>();
seenThrowables.add(rootCause);
while ((rootCause.getCause() != null && !seenThrowables.contains(rootCause.getCause()))) {
seenThrowables.add(rootCause.getCause());
rootCause = rootCause.getCause();
}
return rootCause;
}
}