java-后台生成图表、并将图表保存为PNG图片

创建图表步骤：
* 1：创建数据集合
* 2：创建Chart：
* 3:设置抗锯齿，防止字体显示不清楚
* 4:对柱子进行渲染，
* 5:对其他部分进行渲染
* 6:使用chartPanel接收

1：引包
jcommon-1.0.20.jar
jfreechart-1.0.16-experimental.jar
jfreechart-1.0.16.jar
2:创建工具类
ChartUtils.java

package util;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Paint;
import java.awt.Rectangle;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Vector;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardChartTheme;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.DateTickUnit;
import org.jfree.chart.axis.DateTickUnitType;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.block.BlockBorder;
import org.jfree.chart.labels.ItemLabelAnchor;
import org.jfree.chart.labels.ItemLabelPosition;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
import org.jfree.chart.labels.StandardXYItemLabelGenerator;
import org.jfree.chart.labels.StandardXYToolTipGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.DefaultDrawingSupplier;
import org.jfree.chart.plot.PieLabelLinkStyle;
import org.jfree.chart.plot.PiePlot;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.chart.renderer.category.LineAndShapeRenderer;
import org.jfree.chart.renderer.category.StackedBarRenderer;
import org.jfree.chart.renderer.category.StandardBarPainter;
import org.jfree.chart.renderer.xy.StandardXYBarPainter;
import org.jfree.chart.renderer.xy.XYBarRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.time.Day;
import org.jfree.data.time.TimeSeries;
import org.jfree.ui.RectangleInsets;
import org.jfree.ui.TextAnchor;

/**
 * Jfreechart工具类
 * 

 * 解决中午乱码问题

 * 用来创建类别图表数据集、创建饼图数据集、时间序列图数据集

 * 用来对柱状图、折线图、饼图、堆积柱状图、时间序列图的样式进行渲染

 * 设置X-Y坐标轴样式
 * 

 * 
 */
public class ChartUtils {
    private static String NO_DATA_MSG = "数据加载失败";
    private static Font FONT = new Font("宋体", Font.PLAIN, 12);
    public static Color[] CHART_COLORS = {
            new Color(31,129,188), new Color(92,92,97), new Color(144,237,125), new Color(255,188,117),
            new Color(153,158,255), new Color(255,117,153), new Color(253,236,109), new Color(128,133,232),
            new Color(158,90,102),new Color(255, 204, 102) };//颜色

    static {
        setChartTheme();
    }

    public ChartUtils() {
    }

    /**
     * 中文主题样式 解决乱码
     */
    public static void setChartTheme() {
        // 设置中文主题样式 解决乱码
        StandardChartTheme chartTheme = new StandardChartTheme("CN");
        // 设置标题字体
        chartTheme.setExtraLargeFont(FONT);
        // 设置图例的字体
        chartTheme.setRegularFont(FONT);
        // 设置轴向的字体
        chartTheme.setLargeFont(FONT);
        chartTheme.setSmallFont(FONT);
        chartTheme.setTitlePaint(new Color(51, 51, 51));
        chartTheme.setSubtitlePaint(new Color(85, 85, 85));

        chartTheme.setLegendBackgroundPaint(Color.WHITE);// 设置标注
        chartTheme.setLegendItemPaint(Color.BLACK);//
        chartTheme.setChartBackgroundPaint(Color.WHITE);
        // 绘制颜色绘制颜色.轮廓供应商
        // paintSequence,outlinePaintSequence,strokeSequence,outlineStrokeSequence,shapeSequence

        Paint[] OUTLINE_PAINT_SEQUENCE = new Paint[] { Color.WHITE };
        // 绘制器颜色源
        DefaultDrawingSupplier drawingSupplier = new DefaultDrawingSupplier(CHART_COLORS, CHART_COLORS, OUTLINE_PAINT_SEQUENCE,
                DefaultDrawingSupplier.DEFAULT_STROKE_SEQUENCE, DefaultDrawingSupplier.DEFAULT_OUTLINE_STROKE_SEQUENCE,
                DefaultDrawingSupplier.DEFAULT_SHAPE_SEQUENCE);
        chartTheme.setDrawingSupplier(drawingSupplier);

        chartTheme.setPlotBackgroundPaint(Color.WHITE);// 绘制区域
        chartTheme.setPlotOutlinePaint(Color.WHITE);// 绘制区域外边框
        chartTheme.setLabelLinkPaint(new Color(8, 55, 114));// 链接标签颜色
        chartTheme.setLabelLinkStyle(PieLabelLinkStyle.CUBIC_CURVE);

        chartTheme.setAxisOffset(new RectangleInsets(5, 12, 5, 12));
        chartTheme.setDomainGridlinePaint(new Color(192, 208, 224));// X坐标轴垂直网格颜色
        chartTheme.setRangeGridlinePaint(new Color(192, 192, 192));// Y坐标轴水平网格颜色

        chartTheme.setBaselinePaint(Color.WHITE);
        chartTheme.setCrosshairPaint(Color.BLUE);// 不确定含义
        chartTheme.setAxisLabelPaint(new Color(51, 51, 51));// 坐标轴标题文字颜色
        chartTheme.setTickLabelPaint(new Color(67, 67, 72));// 刻度数字
        chartTheme.setBarPainter(new StandardBarPainter());// 设置柱状图渲染
        chartTheme.setXYBarPainter(new StandardXYBarPainter());// XYBar 渲染

        chartTheme.setItemLabelPaint(Color.black);
        chartTheme.setThermometerPaint(Color.white);// 温度计

        ChartFactory.setChartTheme(chartTheme);
    }

    /**
     * 必须设置文本抗锯齿
     */
    public static void setAntiAlias(JFreeChart chart) {
        chart.setTextAntiAlias(false);

    }

    /**
     * 设置图例无边框，默认黑色边框
     */
    public static void setLegendEmptyBorder(JFreeChart chart) {
        chart.getLegend().setFrame(new BlockBorder(Color.WHITE));

    }

    /**
     * 创建类别数据集合
     */
    public static DefaultCategoryDataset createDefaultCategoryDataset(Vector series, String[] categories) {
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        for (Serie serie : series) {
            String name = serie.getName();
            Vector