使用itextpdf、jfree、transcoder生成清晰的柱状图

本文主要是介绍使用itextpdf、jfree、transcoder生成清晰的柱状图，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

项目需求：在PDF文件中生成柱状图

需求难点：使用网上大家提供能的代码只能完成生成柱状图，但是pdf中展示出来的效果是比较模糊的，尤其是在中文汉字上的表现，基本不能使用

功能实现：

1.相关jar包:

<dependency><groupId>com.itextpdf</groupId><artifactId>itext7-core</artifactId><version>7.0.6</version>
</dependency>
<dependency><groupId>com.itextpdf</groupId><artifactId>itext-asian</artifactId><version>5.2.0</version>
</dependency>
<dependency><groupId>com.itextpdf</groupId><artifactId>font-asian</artifactId><version>7.1.16</version>
</dependency> 
<dependency><groupId>org.jfree</groupId><artifactId>jfreechart</artifactId><version>1.5.4</version>
</dependency>
<dependency><groupId>org.jfree</groupId><artifactId>jcommon</artifactId><version>1.0.24</version>
</dependency>
<dependency><groupId>org.jfree</groupId><artifactId>jfreesvg</artifactId><version>3.4.3</version>
</dependency>
<dependency><groupId>org.apache.xmlgraphics</groupId><artifactId>batik-transcoder</artifactId><version>1.14</version>
</dependency>
<dependency><groupId>org.apache.xmlgraphics</groupId><artifactId>batik-codec</artifactId><version>1.14</version>
</dependency>

2.实现原理：使用JFreeChart生成svg格式图片，然后使用batik.transcoder将svg图片转换成png格式图片，不经过svg转png过程直接生成png格式时图片模糊无法使用。

3.代码实现：

import java.awt.BasicStroke;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.text.SimpleDateFormat;
import java.util.Date;import org.apache.batik.transcoder.Transcoder;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.ImageTranscoder;
import org.apache.batik.transcoder.image.PNGTranscoder;
import org.fusesource.hawtbuf.ByteArrayInputStream;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardChartTheme;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.chart.renderer.category.StandardBarPainter;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.graphics2d.svg.SVGGraphics2D;import com.itextpdf.io.font.PdfEncodings;
import com.itextpdf.io.image.ImageDataFactory;
import com.itextpdf.kernel.color.Color;
import com.itextpdf.kernel.color.DeviceRgb;
import com.itextpdf.kernel.events.PdfDocumentEvent;
import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.kernel.font.PdfFontFactory;
import com.itextpdf.kernel.geom.PageSize;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.border.SolidBorder;
import com.itextpdf.layout.element.Cell;
import com.itextpdf.layout.element.Div;
import com.itextpdf.layout.element.Image;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Table;
import com.itextpdf.layout.property.HorizontalAlignment;
import com.itextpdf.layout.property.TextAlignment;
import com.itextpdf.layout.property.VerticalAlignment;
import com.minxue.util.common.DateUtils;
import com.minxue.util.common.PropertisUtil;
import com.minxue.util.common.StringUtil;
import com.minxue.util.pdf.VacationHoistEventHandlerA4SingleFaceOneCol;
import com.minxue.util.qrCode.QRCodeUtil;/*** @author Administrator* @date 2023年11月23日*/
public class PdfTablesTest {public static void main(String[] args) {try {String studentId = "123456";String temp = DateUtils.formatDateTimeToStr2(DateUtils.getNowTime());String folder1 =PropertisUtil.getInstance().getTempDir() +File.separator +"VacationHoist";File dirfolder1 = new File(folder1);if (!dirfolder1.exists()){dirfolder1.mkdirs();dirfolder1.setReadable(true, false);dirfolder1.setExecutable(true, false);dirfolder1.setWritable(true, false);}String folder2 =PropertisUtil.getInstance().getTempDir() +File.separator +"VacationHoist"+File.separator+studentId;File dirfolder2 = new File(folder2);if (!dirfolder2.exists()){dirfolder2.mkdirs();dirfolder2.setReadable(true, false);dirfolder2.setExecutable(true, false);dirfolder2.setWritable(true, false);}String folder3 =PropertisUtil.getInstance().getTempDir() +File.separator +"VacationHoist"+File.separator+studentId +File.separator + temp;File dirfolder3 = new File(folder3);if (!dirfolder3.exists()){dirfolder3.mkdirs();dirfolder3.setReadable(true, false);dirfolder3.setExecutable(true, false);dirfolder3.setWritable(true, false);}//String doc1 = PropertisUtil.getInstance().getTempDir() +File.separator +"VacationHoist"+File.separator+studentId+File.separator + temp;String fileName1 = PropertisUtil.getInstance().getTempDir() +File.separator +"VacationHoist"+File.separator+studentId+File.separator + temp+File.separator+ "scoreAnaLysis_1.pdf";String filepath = PropertisUtil.getInstance().getTempDir() + File.separator;String qrcodeName = filepath   +PropertisUtil.getInstance().getTemplate()+File.separator+ "qrLogo.jpg";PageSize ps = PageSize.A4;PdfFont sysFont1 = null;String fonts_dir = PropertisUtil.getInstance().getFonts_dir();sysFont1 = PdfFontFactory.createFont(fonts_dir, PdfEncodings.IDENTITY_H, false);Document document = null;PdfDocument pdfDoc = new PdfDocument(new PdfWriter(fileName1));pdfDoc.addEventHandler(PdfDocumentEvent.END_PAGE, new VacationHoistEventHandlerA4SingleFaceOneCol("西安xxxx中       高三（2031班）       xxx【数学】                                       2024届高三入学摸底考试 数学", "https://wx.xxxxxx.com/wechat", qrcodeName, filepath));//传期数 账号document = new Document(pdfDoc, ps);// 构建文档对象createBarChar(document,sysFont1);document.close();} catch (Exception e) {e.printStackTrace();}}public static void createBarChar(Document document, PdfFont sysFont1) throws Exception {//echart图表DefaultCategoryDataset defaultCategoryDataset = new DefaultCategoryDataset();defaultCategoryDataset.addValue(5,"其他人","160-150");defaultCategoryDataset.addValue(20,"其他人","150-140");defaultCategoryDataset.addValue(100,"其他人","140-130");defaultCategoryDataset.addValue(11,"其他人","130-120");defaultCategoryDataset.addValue(8,"其他人","120-110");defaultCategoryDataset.addValue(5,"其他人","110-100");defaultCategoryDataset.addValue(14,"我的位置","100-90");defaultCategoryDataset.addValue(7,"其他人","90-80");defaultCategoryDataset.addValue(30,"其他人","80-70");defaultCategoryDataset.addValue(7,"其他人","70-60");defaultCategoryDataset.addValue(8,"其他人","60-50");defaultCategoryDataset.addValue(9,"其他人","50-40");defaultCategoryDataset.addValue(4,"其他人","40-30");defaultCategoryDataset.addValue(3,"其他人","30-20");defaultCategoryDataset.addValue(2,"其他人","20-10");defaultCategoryDataset.addValue(12,"其他人","10-0");StandardChartTheme chartTheme = new StandardChartTheme("CN");chartTheme.setExtraLargeFont(new java.awt.Font("微软雅黑", java.awt.Font.BOLD,8));chartTheme.setRegularFont(new java.awt.Font("微软雅黑", java.awt.Font.BOLD,8));chartTheme.setLargeFont(new java.awt.Font("微软雅黑", java.awt.Font.BOLD,8));ChartFactory.setChartTheme(chartTheme);//JFreeChart chart = ChartFactory.createBarChart("趋势图", "各项分布","比例分值",defaultCategoryDataset);JFreeChart chart = ChartFactory.createBarChart("", "","人数",defaultCategoryDataset);chart.setBackgroundPaint(java.awt.Color.white);//chart.setTextAntiAlias(false);//chart.setAntiAlias(true);CategoryPlot categoryplot = chart.getCategoryPlot();// 图本身org.jfree.chart.axis.CategoryAxis domainAxis = categoryplot.getDomainAxis();domainAxis.setCategoryLabelPositions(CategoryLabelPositions.createUpRotationLabelPositions(70));BarRenderer brender = new BarRenderer();//设置柱子为平面效果brender.setBarPainter(new StandardBarPainter()); brender.setSeriesPaint(0, java.awt.Color.decode("#61CAFF"));brender.setSeriesPaint(1, java.awt.Color.decode("#78AB41"));brender.setSeriesStroke(0, new BasicStroke(4));brender.setSeriesStroke(0, new BasicStroke(4));brender.setShadowVisible(false);//设置柱状图的顶端显示数字brender.setIncludeBaseInRange(true);brender.setDefaultItemLabelGenerator(new StandardCategoryItemLabelGenerator());brender.setDefaultItemLabelsVisible(true);brender.setDefaultItemLabelFont(new java.awt.Font("微软雅黑", java.awt.Font.BOLD,8));//brender.setBarPainter(new StandardBarPainter());// 标准的渲染器(支持颜色渐变)brender.setItemMargin(0);// 设置图的背景为白色categoryplot.setBackgroundPaint(java.awt.Color.WHITE);categoryplot.setRangeGridlinePaint(java.awt.Color.decode("#B6A2DE"));categoryplot.setOutlineVisible(false);categoryplot.setRenderer(brender);SVGGraphics2D g2 = new SVGGraphics2D(500, 300);java.awt.geom.Rectangle2D area = new java.awt.geom.Rectangle2D.Double(0, 0, 500, 300);chart.draw(g2, area );InputStream is = new ByteArrayInputStream(g2.getSVGDocument().getBytes());OutputStream out = new FileOutputStream(new File("D:\\data\\mxjy_pdf\\VacationHoist\\x.png"));out = new BufferedOutputStream(out);Transcoder transcoder = new PNGTranscoder();TranscoderInput input = new TranscoderInput(is);TranscoderOutput output = new TranscoderOutput(out);transcoder.addTranscodingHint(ImageTranscoder.KEY_WIDTH, 1024f);transcoder.addTranscodingHint(ImageTranscoder.KEY_HEIGHT, 614f);transcoder.transcode(input, output);Image image = new Image(ImageDataFactory.create("D:\\data\\mxjy_pdf\\VacationHoist\\x.png"));document.add(image);}
}

4.实现效果：