minmax.java

jrobin,使用纯java实现的RRD数据库,使用RRD数据库来统计数据.

package org.jrobin.demo;

import org.jrobin.core.*;
import org.jrobin.graph.*;

import java.io.*;
import java.awt.*;

class MinMax {
	public static void main(String[] args) throws RrdException, IOException {
		long start = Util.getTime(), end = start + 300 * 300;
		String rrdFile = Util.getJRobinDemoPath("minmax.rrd");
		String pngFile = Util.getJRobinDemoPath("minmax.png");
		// create
		RrdDef rrdDef = new RrdDef(rrdFile, start - 1, 300);
		rrdDef.addDatasource("a", "GAUGE", 600, Double.NaN, Double.NaN);
		rrdDef.addArchive("AVERAGE", 0.5, 1, 300);
		rrdDef.addArchive("MIN", 0.5, 12, 300);
		rrdDef.addArchive("MAX", 0.5, 12, 300);
		RrdDb rrdDb = new RrdDb(rrdDef);
		// update
		for (long t = start; t < end; t += 300) {
			Sample sample = rrdDb.createSample(t);
			sample.setValue("a", Math.sin(t / 3000.0) * 50 + 50);
			sample.update();
		}
		// graph
		RrdGraphDef gDef = new RrdGraphDef();
		gDef.setFilename(pngFile);
		gDef.setWidth(450);
		gDef.setHeight(250);
		gDef.setImageFormat("png");
		gDef.setTimeSpan(start, start + 86400);
		gDef.setTitle("RRDTool's MINMAX.pl demo");
		gDef.datasource("a", rrdFile, "a", "AVERAGE");
		gDef.datasource("b", rrdFile, "a", "MIN");
		gDef.datasource("c", rrdFile, "a", "MAX");
		gDef.area("a", Color.decode("0xb6e4"), "real");
		gDef.line("b", Color.decode("0x22e9"), "min");
		gDef.line("c", Color.decode("0xee22"), "max");
		new RrdGraph(gDef);
	}
}