info.fetter.rrdclient.GraphCommand.java Source code

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Here is the source code for info.fetter.rrdclient.GraphCommand.java

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package info.fetter.rrdclient;

/*
 * Copyright 2013 Didier Fetter
 *
 * 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.
 *
 */

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;

import javax.imageio.ImageIO;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.cli.PosixParser;
import org.apache.log4j.Logger;

/**
 * Wrapper for the RRD graph command.
 * 
 * @author Didier Fetter
 *
 */
public class GraphCommand extends RRDCommand {
    private static Logger logger = Logger.getLogger(GraphCommand.class);
    private String[] args;
    private boolean isOutputParsed = false;
    private BufferedImage image;

    /**
     * Create a wrapper object for the RRD graph command.
     * 
     * @param args
     */
    public GraphCommand(String... args) {
        try {
            this.args = args;
            CommandLineParser parser = new PosixParser();
            Options options = new Options();
            options.addOption("a", "imgformat", true, "image format");
            options.addOption("s", "start", true, "start (default end-1day)");
            options.addOption("e", "end", true, "end (default now)");
            options.addOption("t", "title", true, "graph title");
            options.addOption("n", "font", true, "font");
            options.addOption("w", "width", true, "image width");
            options.addOption("h", "height", true, "image height");
            options.addOption("b", "base", true, "base value");
            options.addOption("A", "alt-autoscale", false, "alternate scale algorithm");
            options.addOption("M", "alt-autoscale-max", false, "alternate scale algorithm (max value only)");
            options.addOption("J", "alt-autoscale-min", false, "alternate scale algorithm (min value only)");
            options.addOption("l", "lower-limit", true, "lower limit");
            options.addOption("u", "upper-limit", true, "upper limit");
            options.addOption("r", "rigid", false, "rigid boundaries");
            options.addOption("v", "vertical-label", true, "vertical label");
            options.addOption("E", "slope-mode", false, "enable slope mode");
            options.addOption("i", "interlaced", false, "interlaced image");
            options.addOption("o", "logarithmic", false, "logarithmic scale");
            options.addOption("z", "units", true, "use SI notation for logarithmic scale");
            options.addOption("y", "y-grid", true, "Y grid step");
            options.addOption("X", "units-exponent", true, "sets the 10**exponent scaling of the y-axis values");

            CommandLine cmd = parser.parse(options, args, false);
            for (Option option : cmd.getOptions()) {
                logger.trace("Parsed option : " + option.getLongOpt());
            }
            for (String arg : cmd.getArgs()) {
                logger.trace("Remaining arg : " + arg);
            }

        } catch (ParseException e) {
            throw new IllegalArgumentException(e);
        }
    }

    @Override
    public void execute(OutputStream out) {
        String command = "graph";
        for (String arg : args) {
            command += " " + arg;
        }
        try {
            ByteBuffer response = sendCommandToServer(command);
            WritableByteChannel channel = Channels.newChannel(out);
            channel.write(response);
            isOutputParsed = false;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }

    @Override
    public void execute() {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        execute(out);
        try {
            parseOutput(out.toByteArray());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    protected void parseOutput(byte[] output) throws IOException {
        if (isOutputParsed)
            return;

        ByteArrayInputStream in = new ByteArrayInputStream(output);
        image = ImageIO.read(in);
        if (logger.isTraceEnabled())
            logger.trace("Image size : " + image.getWidth() + "x" + image.getHeight());

        isOutputParsed = true;
    }

    public BufferedImage getImage() {
        return image;
    }

}