org.apache.logging.log4j.core.appender.rolling.action.SortingVisitor Maven / Gradle / Ivy
/*
* 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.appender.rolling.action;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.status.StatusLogger;
/**
* FileVisitor that sorts files.
*/
public class SortingVisitor extends SimpleFileVisitor {
private static final Logger LOGGER = StatusLogger.getLogger();
private final PathSorter sorter;
private final List collected = new ArrayList<>();
/**
* Constructs a new SortingVisitor.
*
* @param sorter Interface implementation which can sort paths.
*/
public SortingVisitor(final PathSorter sorter) {
this.sorter = Objects.requireNonNull(sorter, "sorter");
}
@Override
public FileVisitResult visitFile(final Path path, final BasicFileAttributes attrs) throws IOException {
collected.add(new PathWithAttributes(path, attrs));
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(final Path file, final IOException ioException) throws IOException {
// LOG4J2-2677: Appenders may rollover and purge in parallel. SimpleVisitor rethrows exceptions from
// failed attempts to load file attributes.
if (ioException instanceof NoSuchFileException) {
LOGGER.info("File {} could not be accessed, it has likely already been deleted", file, ioException);
return FileVisitResult.CONTINUE;
} else {
return super.visitFileFailed(file, ioException);
}
}
public List getSortedPaths() {
Collections.sort(collected, sorter);
return collected;
}
}