1.라인 그래프

		CombinedDomainXYPlot plot = new CombinedDomainXYPlot(new DateAxis("Time"));
		plot.setBackgroundPaint(Color.lightGray);
		plot.setDomainGridlinePaint(Color.white);
		plot.setRangeGridlinePaint(Color.white);
		plot.setForegroundAlpha(0.5f);
		plot.setBackgroundAlpha(0.5f);
		TimeSeriesCollection dataset = new TimeSeriesCollection();
		dataset.addSeries(new TimeSeries("Speed1", Millisecond.class));
		dataset.addSeries(new TimeSeries("Speed2", Millisecond.class));
		NumberAxis axisY = new NumberAxis("ms");
		axisY.setAutoRangeIncludesZero(false);
		axisY.setRange(0, 100);
		XYPlot subplot = new XYPlot(dataset, null, axisY, new StandardXYItemRenderer());
		subplot.setBackgroundPaint(Color.lightGray);
		subplot.setDomainGridlinePaint(Color.white);
		subplot.setRangeGridlinePaint(Color.white);
		plot.add(subplot);
		// 시작지점을 0 으로 초기화
		Calendar cal = Calendar.getInstance();
		cal.setTime(now.getTime());
		cal.set(Calendar.HOUR_OF_DAY, 0);
		cal.set(Calendar.MINUTE, 0);
		cal.set(Calendar.SECOND, 0);
		cal.set(Calendar.MILLISECOND, 0);
		dataset.getSeries(0).add(new Millisecond(cal.getTime()), 0);
		dataset.getSeries(1).add(new Millisecond(cal.getTime()), 0);
		// 아래와 같이 datas에 데이터를 그래프로써 추가
		for (int i=0; i<datas.length; i++) {
	       dataset.getSeries(0).add(new Millisecond(now.getTime()), datas[i].value1);
	       dataset.getSeries(1).add(new Millisecond(now.getTime()), datas[i].value2);
		}
		// JFreeChart로 그래프 본체 생성
		JFreeChart chart = new JFreeChart("GRAPH TITLE", plot);
		chart.setBorderPaint(Color.black);
		chart.setBorderVisible(true);
		chart.setBackgroundPaint(Color.white);
		// 범례
		LegendTitle legend = chart.getLegend();
		legend.setBackgroundPaint(Color.white);
		legend.setMargin(10d, 10d, 10d, 10d);
		// 이미지 파일로 저장하기
		File pngFile = new File("output.png");
		ChartUtilities.saveChartAsPNG(pngFile, chart, 800, 600);

2.원형 그래프

		DefaultPieDataset pieDataset = new DefaultPieDataset();
		Set<String> keys = new TreeSet<String>(countByOSType.keySet());
		for (String k : keys) {
			pieDataset.setValue(k, new Double(countByOSType.get(k)));
		}
		JFreeChart pieChart = ChartFactory.createPieChart3D("GRAPH TITLE", pieDataset, true, true, false);
		/*
		 * // 3D PIE PiePlot3D localPiePlot3D = (PiePlot3D)pieChart.getPlot();
		 * localPiePlot3D.setDarkerSides(true);
		 * localPiePlot3D.setStartAngle(290.0D);
		 * localPiePlot3D.setDirection(Rotation.CLOCKWISE);
		 * localPiePlot3D.setForegroundAlpha(0.5F);
		 */
		// 2D PIE
		pieChart.setBackgroundPaint(new GradientPaint(new Point(0, 0), new Color(20, 20, 20), new Point(400, 200), Color.DARK_GRAY));
		// GRAPH TITLE
		TextTitle graphTitle = pieChart.getTitle();
		graphTitle.setHorizontalAlignment(HorizontalAlignment.CENTER);
		graphTitle.setPaint(new Color(240, 240, 240));
		graphTitle.setFont(new Font("Meiryo UI", 1, 26));
		// GRAPH VISUAL
		PiePlot localPiePlot = (PiePlot) pieChart.getPlot();
		localPiePlot.setBackgroundPaint(null);
		localPiePlot.setInteriorGap(0.04D);
		localPiePlot.setOutlineVisible(false);
		// localPiePlot.setSectionPaint("Android", new RadialGradientPaint(new
		// Point2D.Float(0.0F, 0.0F), 200.0F, new float[]{ 0.0F, 1.0F }, new
		// Color[] { new Color(200, 200, 255), Color.BLUE }));
		// localPiePlot.setSectionPaint("iPhone", new RadialGradientPaint(new
		// Point2D.Float(0.0F, 0.0F), 200.0F, new float[]{ 0.0F, 1.0F }, new
		// Color[] { new Color(200, 200, 255), Color.RED }));
		localPiePlot.setBaseSectionOutlinePaint(Color.WHITE);
		localPiePlot.setSectionOutlinesVisible(true);
		localPiePlot.setBaseSectionOutlineStroke(new BasicStroke(2.0F));
		// LABEL
		PieSectionLabelGenerator generator = new StandardPieSectionLabelGenerator("{0}: {1} ({2})", new DecimalFormat("0"), new DecimalFormat("0.0%"));
		localPiePlot.setLabelGenerator(generator);
		localPiePlot.setLabelFont(new Font("Meiryo UI", 1, 15));
		localPiePlot.setLabelLinkPaint(Color.WHITE);
		// localPiePlot.setLabelLinkStroke(new BasicStroke(2.0F));
		localPiePlot.setLabelOutlineStroke(null);
		localPiePlot.setLabelPaint(Color.WHITE);
		localPiePlot.setLabelBackgroundPaint(null);
		// GRAPH COMMENT
		TextTitle graphCommentText = new TextTitle("Source: http://jo.centis1504.net", new Font("Meiryo UI", 0, 12));
		graphCommentText.setPaint(Color.WHITE);
		graphCommentText.setPosition(RectangleEdge.BOTTOM);
		graphCommentText.setHorizontalAlignment(HorizontalAlignment.RIGHT);
		pieChart.addSubtitle(graphCommentText);
		// save
		File pngFile = new File("output.png");
		ChartUtilities.saveChartAsPNG(pngFile, pieChart, 800, 600);

文字化けしないようにする

ChartFactory.setChartTheme(StandardChartTheme.createLegacyTheme());