net.oneandone.stool.util.LogReader Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of main Show documentation
Stool's main component. Java Library, cli, setup code.
There is a newer version: 4.0.3
/**
 * Copyright 1&1 Internet AG, https://github.com/1and1/
 *
 * 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 net.oneandone.stool.util;

import net.oneandone.sushi.fs.file.FileNode;
import net.oneandone.sushi.io.LineFormat;
import net.oneandone.sushi.io.LineReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.zip.GZIPInputStream;

public class LogReader implements AutoCloseable {
    public static LogReader create(FileNode directory) throws IOException {
        List files;
        Iterator iter;
        FileNode file;

        files = directory.list();
        iter = files.iterator();
        while (iter.hasNext()) {
            file = iter.next();
            if (file.isDirectory()) {
                iter.remove();
            } else if (!file.getName().endsWith(".log") && !file.getName().endsWith(".log.gz")) {
                iter.remove();
            }
        }
        Collections.sort(files, (left, right) -> left.getName().compareTo(right.getName()));
        return new LogReader(files);
    }

    private final List files;
    private LineReader reader;

    public LogReader(List files) {
        this.files = files;
        this.reader = null;
    }

    public LogEntry next() throws IOException {
        FileNode file;
        String line;
        InputStream src;

        while (true) {
            if (reader == null) {
                if (files.isEmpty()) {
                    return null;
                }
                file = files.remove(0);
                src = file.newInputStream();
                if (file.getName().endsWith(".gz")) {
                    src = new GZIPInputStream(src);
                }
                reader = new LineReader(new InputStreamReader(src, "utf8"), LineFormat.RAW_FORMAT);
            }
            line = reader.next();
            if (line != null) {
                return LogEntry.parse(line);
            }
            reader.close();
            reader = null;
        }
    }

    @Override
    public void close() throws Exception {
        if (reader != null) {
            reader.close();
        }
    }
}