FileOverwriterOutputWriter.java

/*
 * Copyright (c) 2010-2013 the original author or authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
package org.jmxtrans.agent;

import org.jmxtrans.agent.util.io.IoUtils;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.*;
import java.nio.channels.FileChannel;
import java.nio.charset.StandardCharsets;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Map;
import java.util.TimeZone;

import static org.jmxtrans.agent.util.ConfigurationUtils.getBoolean;
import static org.jmxtrans.agent.util.ConfigurationUtils.getString;

/**
 * @author <a href="mailto:cleclerc@cloudbees.com">Cyrille Le Clerc</a>
 */
public class FileOverwriterOutputWriter extends AbstractOutputWriter {

    public final static String SETTING_FILE_NAME = "fileName";
    public final static String SETTING_FILE_NAME_DEFAULT_VALUE = "jmxtrans-agent.data";
    public final static String SETTING_SHOW_TIMESTAMP = "showTimeStamp";
    public final static Boolean SETTING_SHOW_TIMESTAMP_DEFAULT = false;
    protected Writer temporaryFileWriter;
    protected File temporaryFile;
    protected File file = new File(SETTING_FILE_NAME_DEFAULT_VALUE);
    protected Boolean showTimeStamp;
    private static DateFormat dfISO8601 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
    
    @Override
    public synchronized void postConstruct(Map<String, String> settings) {
        super.postConstruct(settings);
        dfISO8601.setTimeZone(TimeZone.getTimeZone("GMT"));
        file = new File(getString(settings, SETTING_FILE_NAME, SETTING_FILE_NAME_DEFAULT_VALUE));
        showTimeStamp = getBoolean(settings, SETTING_SHOW_TIMESTAMP, SETTING_SHOW_TIMESTAMP_DEFAULT);
        logger.log(getInfoLevel(), "FileOverwriterOutputWriter configured with file " + file.getAbsolutePath());
    }

    protected Writer getTemporaryFileWriter() throws IOException {
        if (temporaryFile == null) {
            temporaryFile = File.createTempFile("jmxtrans-agent-", ".data");
            temporaryFile.deleteOnExit();
            if (logger.isLoggable(getDebugLevel()))
                logger.log(getDebugLevel(), "Created temporary file " + temporaryFile.getAbsolutePath());

            temporaryFileWriter = null;
        }
        if (temporaryFileWriter == null) {
            temporaryFileWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(temporaryFile, false), StandardCharsets.UTF_8));
        }

        return temporaryFileWriter;
    }

    @Override
    public void writeInvocationResult(String invocationName, Object value) throws IOException {
        writeQueryResult(invocationName, null, value);
    }

    public synchronized void writeQueryResult(@Nonnull String name, @Nullable String type, @Nullable Object value) throws IOException {
        try {
            if (showTimeStamp){
                getTemporaryFileWriter().write("["+dfISO8601.format(Calendar.getInstance().getTime()) +"] "+name + " " + value + "\n");
            } else {
                getTemporaryFileWriter().write(name + " " + value + "\n");
            }
            
        } catch (IOException e) {
            releaseTemporaryWriter();
            throw e;
        }
    }

    protected void releaseTemporaryWriter() {
        try {
            IoUtils.closeQuietly(getTemporaryFileWriter());
        } catch (IOException e) {
            // silently skip
        }
        if (temporaryFile != null) {
            boolean deleted = temporaryFile.delete();
            if (deleted) {
                logger.warning("Failure to delete " + temporaryFile);
            }
        }
        temporaryFile = null;

    }

    @Override
    public synchronized void postCollect() throws IOException {
        try {
            getTemporaryFileWriter().close();
            if (logger.isLoggable(getDebugLevel()))
                logger.log(getDebugLevel(), "Overwrite " + file.getAbsolutePath() + " by " + temporaryFile.getAbsolutePath());
            IoUtils.replaceFile(temporaryFile, file);
        } finally {
            temporaryFileWriter = null;
        }
    }
}