com.vlkan.log4j2.logstash.layout.util.Throwables Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of log4j2-logstash-layout Show documentation

There is a newer version: 1.0.5

Show newest version

/*
 * Copyright 2017-2020 Volkan Yazıcı
 *
 * 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 permits and
 * limitations under the License.
 */

package com.vlkan.log4j2.logstash.layout.util;

public enum Throwables {;

    public static Throwable getRootCause(Throwable throwable) {

        // Keep a second pointer that slowly walks the causal chain. If the fast pointer ever catches
        // the slower pointer, then there's a loop.
        Throwable slowPointer = throwable;
        boolean advanceSlowPointer = false;

        Throwable cause;
        while ((cause = throwable.getCause()) != null) {
            throwable = cause;
            if (throwable == slowPointer) {
                throw new IllegalArgumentException("loop in causal chain", throwable);
            }
            if (advanceSlowPointer) {
                slowPointer = slowPointer.getCause();
            }
            advanceSlowPointer = !advanceSlowPointer; // only advance every other iteration
        }
        return throwable;

    }

}