itext7学习笔记

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来源：https://blog.csdn.net/u012397189/category_9270695.html

itext7学习笔记——第2章实践&example

转x33g5p2x  于2021-12-28 转载在 其他  
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本章的例子，请参考我翻译的博文：itext7学习笔记——第2章,里面有详细的解释,有什么不懂得也可以评论或者私信我！

例子1：简单的坐标系

简单地画一个x和y轴坐标系，代码如下：

  1. import com.itextpdf.kernel.geom.PageSize;
  2. import com.itextpdf.kernel.pdf.PdfDocument;
  3. import com.itextpdf.kernel.pdf.PdfPage;
  4. import com.itextpdf.kernel.pdf.PdfWriter;
  5. import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
  6. import com.itextpdf.kernel.pdf.canvas.PdfCanvasConstants;
  8. import java.io.File;
  9. import java.io.IOException;
  11. public class C02E01_Axes {
  13.     public static final String DEST = "results/chapter02/axes.pdf";
  15.     public static void main(String args[]) throws IOException {
  16.         File file = new File(DEST);
  17.         file.getParentFile().mkdirs();
  18.         new C02E01_Axes().createPdf(DEST);
  19.     }
  21.     public void createPdf(String dest) throws IOException {
  23.         //Initialize PDF document
  24.         PdfDocument pdf = new PdfDocument(new PdfWriter(dest));
  26.         PageSize ps = PageSize.A4.rotate();
  27.         PdfPage page = pdf.addNewPage(ps);
  29.         PdfCanvas canvas = new PdfCanvas(page);
  30.         //Replace the origin of the coordinate system to the center of the page
  31.         canvas.concatMatrix(1, 0, 0, 1, ps.getWidth() / 2, ps.getHeight() / 2);
  33.         C02E01_Axes.drawAxes(canvas, ps);
  35.         //Close document
  36.         pdf.close();
  38.     }
  40.     public static void drawAxes(PdfCanvas canvas, PageSize ps) {
  41.         //Draw X axis
  42.         canvas.moveTo(-(ps.getWidth() / 2 - 15), 0)
  43.                 .lineTo(ps.getWidth() / 2 - 15, 0)
  44.                 .stroke();
  46.         //Draw X axis arrow
  47.         canvas.setLineJoinStyle(PdfCanvasConstants.LineJoinStyle.ROUND)
  48.                 .moveTo(ps.getWidth() / 2 - 25, -10)
  49.                 .lineTo(ps.getWidth() / 2 - 15, 0)
  50.                 .lineTo(ps.getWidth() / 2 - 25, 10).stroke()
  51.                 .setLineJoinStyle(PdfCanvasConstants.LineJoinStyle.MITER);
  53.         //Draw Y axis
  54.         canvas.moveTo(0, -(ps.getHeight() / 2 - 15))
  55.                 .lineTo(0, ps.getHeight() / 2 - 15)
  56.                 .stroke();
  58.         //Draw Y axis arrow
  59.         canvas.saveState()
  60.                 .setLineJoinStyle(PdfCanvasConstants.LineJoinStyle.ROUND)
  61.                 .moveTo(-10, ps.getHeight() / 2 - 25)
  62.                 .lineTo(0, ps.getHeight() / 2 - 15)
  63.                 .lineTo(10, ps.getHeight() / 2 - 25).stroke()
  64.                 .restoreState();
  66.         //Draw X serif
  67.         for (int i = -((int) ps.getWidth() / 2 - 61); i < ((int) ps.getWidth() / 2 - 60); i += 40) {
  68.             canvas.moveTo(i, 5).lineTo(i, -5);
  69.         }
  70.         //Draw Y serif
  71.         for (int j = -((int) ps.getHeight() / 2 - 57); j < ((int) ps.getHeight() / 2 - 56); j += 40) {
  72.             canvas.moveTo(5, j).lineTo(-5, j);
  73.         }
  74.         canvas.stroke();
  75.     }
  76. }

例子2：坐标系和网格线

在坐标系的基础上，分割坐标系，画出网格线，代码如下：

  1. import com.itextpdf.kernel.color.Color;
  2. import com.itextpdf.kernel.color.DeviceCmyk;
  3. import com.itextpdf.kernel.geom.PageSize;
  4. import com.itextpdf.kernel.pdf.PdfDocument;
  5. import com.itextpdf.kernel.pdf.PdfPage;
  6. import com.itextpdf.kernel.pdf.PdfWriter;
  7. import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
  9. import java.io.File;
  10. import java.io.IOException;
  12. public class C02E02_GridLines {
  14.     public static final String DEST = "results/chapter02/grid_lines.pdf";
  16.     public static void main(String args[]) throws IOException {
  17.         File file = new File(DEST);
  18.         file.getParentFile().mkdirs();
  19.         new C02E02_GridLines().createPdf(DEST);
  20.     }
  22.     public void createPdf(String dest) throws IOException {
  24.         //Initialize PDF document
  25.         PdfDocument pdf = new PdfDocument(new PdfWriter(dest));
  27.         PageSize ps = PageSize.A4.rotate();
  28.         PdfPage page = pdf.addNewPage(ps);
  30.         PdfCanvas canvas = new PdfCanvas(page);
  31.         //Replace the origin of the coordinate system to the center of the page
  32.         canvas.concatMatrix(1, 0, 0, 1, ps.getWidth() / 2, ps.getHeight() / 2);
  34.         Color grayColor = new DeviceCmyk(0.f, 0.f, 0.f, 0.875f);
  35.         Color greenColor = new DeviceCmyk(1.f, 0.f, 1.f, 0.176f);
  36.         Color blueColor = new DeviceCmyk(1.f, 0.156f, 0.f, 0.118f);
  38.         canvas.setLineWidth(0.5f).setStrokeColor(blueColor);
  40.         //Draw horizontal grid lines
  41.         for (int i = -((int) ps.getHeight() / 2 - 57); i < ((int) ps.getHeight() / 2 - 56); i += 40) {
  42.             canvas.moveTo(-(ps.getWidth() / 2 - 15), i)
  43.                     .lineTo(ps.getWidth() / 2 - 15, i);
  44.         }
  45.         //Draw vertical grid lines
  46.         for (int j = -((int) ps.getWidth() / 2 - 61); j < ((int) ps.getWidth() / 2 - 60); j += 40) {
  47.             canvas.moveTo(j, -(ps.getHeight() / 2 - 15))
  48.                     .lineTo(j, ps.getHeight() / 2 - 15);
  49.         }
  50.         canvas.stroke();
  52.         //Draw axes
  53.         canvas.setLineWidth(3).setStrokeColor(grayColor);
  54.         C02E01_Axes.drawAxes(canvas, ps);
  56.         //Draw plot
  57.         canvas.setLineWidth(2).setStrokeColor(greenColor)
  58.                 .setLineDash(10, 10, 8)
  59.                 .moveTo(-(ps.getWidth() / 2 - 15), -(ps.getHeight() / 2 - 15))
  60.                 .lineTo(ps.getWidth() / 2 - 15, ps.getHeight() / 2 - 15).stroke();
  62.         //Close document
  63.         pdf.close();
  65.     }
  66. }

例子3：成段的文字和字体

这里我们简单显示星球大战5帝国反击战的开头的文字，代码如下：

  1. import com.itextpdf.io.font.FontConstants;
  2. import com.itextpdf.kernel.font.PdfFontFactory;
  3. import com.itextpdf.kernel.geom.PageSize;
  4. import com.itextpdf.kernel.pdf.PdfDocument;
  5. import com.itextpdf.kernel.pdf.PdfPage;
  6. import com.itextpdf.kernel.pdf.PdfWriter;
  7. import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
  9. import java.io.File;
  10. import java.io.IOException;
  11. import java.util.ArrayList;
  12. import java.util.List;
  14. public class C02E03_StarWars {
  16.     public static final String DEST = "results/chapter02/star_wars.pdf";
  18.     public static void main(String args[]) throws IOException {
  19.         File file = new File(DEST);
  20.         file.getParentFile().mkdirs();
  21.         new C02E03_StarWars().createPdf(DEST);
  22.     }
  24.     public void createPdf(String dest) throws IOException {
  26.         //Initialize PDF document
  27.         PdfDocument pdf = new PdfDocument(new PdfWriter(dest));
  29.         //Add new page
  30.         PageSize ps = PageSize.A4;
  31.         PdfPage page = pdf.addNewPage(ps);
  33.         PdfCanvas canvas = new PdfCanvas(page);
  35.         List<String> text = new ArrayList();
  36.         text.add(" Episode V ");
  37.         text.add(" THE EMPIRE STRIKES BACK ");
  38.         text.add("It is a dark time for the");
  39.         text.add("Rebellion. Although the Death");
  40.         text.add("Star has been destroyed,");
  41.         text.add("Imperial troops have driven the");
  42.         text.add("Rebel forces from their hidden");
  43.         text.add("base and pursued them across");
  44.         text.add("the galaxy.");
  45.         text.add("Evading the dreaded Imperial");
  46.         text.add("Starfleet, a group of freedom");
  47.         text.add("fighters led by Luke Skywalker");
  48.         text.add("has established a new secret");
  49.         text.add("base on the remote ice world");
  50.         text.add("of Hoth...");
  52.         //Replace the origin of the coordinate system to the top left corner
  53.         canvas.concatMatrix(1, 0, 0, 1, 0, ps.getHeight());
  54.         canvas.beginText()
  55.                 .setFontAndSize(PdfFontFactory.createFont(FontConstants.COURIER_BOLD), 14)
  56.                 .setLeading(14 * 1.2f)
  57.                 .moveText(70, -40);
  58.         for (String s : text) {
  59.             //Add text and move to the next line
  60.             canvas.newlineShowText(s);
  61.         }
  62.         canvas.endText();
  64.         //Close document
  65.         pdf.close();
  67.     }
  68. }

例子4：炫酷的文字效果

我们在第三个例子的基础上，添加炫酷的效果，代码如下：

  1. import com.itextpdf.io.font.FontConstants;
  2. import com.itextpdf.kernel.color.Color;
  3. import com.itextpdf.kernel.color.DeviceCmyk;
  4. import com.itextpdf.kernel.font.PdfFontFactory;
  5. import com.itextpdf.kernel.geom.PageSize;
  6. import com.itextpdf.kernel.pdf.PdfDocument;
  7. import com.itextpdf.kernel.pdf.PdfPage;
  8. import com.itextpdf.kernel.pdf.PdfWriter;
  9. import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
  11. import java.io.File;
  12. import java.io.IOException;
  13. import java.util.ArrayList;
  14. import java.util.List;
  16. public class C02E04_StarWarsCrawl {
  18.     public static final String DEST = "results/chapter02/star_wars_crawl.pdf";
  20.     public static void main(String args[]) throws IOException {
  21.         File file = new File(DEST);
  22.         file.getParentFile().mkdirs();
  23.         new C02E04_StarWarsCrawl().createPdf(DEST);
  24.     }
  26.     public void createPdf(String dest) throws IOException {
  28.         List<String> text = new ArrayList();
  29.         text.add(" Episode V ");
  30.         text.add(" THE EMPIRE STRIKES BACK ");
  31.         text.add("It is a dark time for the");
  32.         text.add("Rebellion. Although the Death");
  33.         text.add("Star has been destroyed,");
  34.         text.add("Imperial troops have driven the");
  35.         text.add("Rebel forces from their hidden");
  36.         text.add("base and pursued them across");
  37.         text.add("the galaxy.");
  38.         text.add("Evading the dreaded Imperial");
  39.         text.add("Starfleet, a group of freedom");
  40.         text.add("fighters led by Luke Skywalker");
  41.         text.add("has established a new secret");
  42.         text.add("base on the remote ice world");
  43.         text.add("of Hoth...");
  45.         int maxStringWidth = 0;
  46.         for (String fragment : text) {
  47.             if (fragment.length() > maxStringWidth) maxStringWidth = fragment.length();
  48.         }
  50.         //Initialize PDF document
  51.         PdfDocument pdf = new PdfDocument(new PdfWriter(dest));
  53.         //Add new page
  54.         PageSize ps = PageSize.A4;
  55.         PdfPage page = pdf.addNewPage(ps);
  57.         PdfCanvas canvas = new PdfCanvas(page);
  59.         //Set black background
  60.         canvas.rectangle(0, 0, ps.getWidth(), ps.getHeight())
  61.                 .setColor(Color.BLACK, true)
  62.                 .fill();
  64.         //Replace the origin of the coordinate system to the top left corner
  65.         canvas.concatMatrix(1, 0, 0, 1, 0, ps.getHeight());
  66.         Color yellowColor = new DeviceCmyk(0.f, 0.0537f, 0.769f, 0.051f);
  67.         float lineHeight = 5;
  68.         float yOffset = -40;
  69.         canvas.beginText()
  70.                 .setFontAndSize(PdfFontFactory.createFont(FontConstants.COURIER_BOLD), 1)
  71.                 .setColor(yellowColor, true);
  72.         for (int j = 0; j < text.size(); j++) {
  73.             String line = text.get(j);
  74.             float xOffset = ps.getWidth() / 2 - 45 - 8 * j;
  75.             float fontSizeCoeff = 6 + j;
  76.             float lineSpacing = (lineHeight + j) * j / 1.5f;
  77.             int stringWidth = line.length();
  78.             for (int i = 0; i < stringWidth; i++) {
  79.                 float angle = (maxStringWidth / 2 - i) / 2f;
  80.                 float charXOffset = (4 + (float) j / 2) * i;
  81.                 canvas.setTextMatrix(fontSizeCoeff, 0,
  82.                         angle, fontSizeCoeff / 1.5f,
  83.                         xOffset + charXOffset, yOffset - lineSpacing)
  84.                         .showText(String.valueOf(line.charAt(i)));
  85.             }
  86.         }
  87.         canvas.endText();
  89.         //Close document
  90.         pdf.close();
  92.     }
  93. }

Example代码下载

本章代码可在如下地址下载（IDEA工程）：iText7——第二章源代码工程

版权说明 : 本文为转载文章, 版权归原作者所有 版权申明

原文链接 : https://blog.csdn.net/u012397189/article/details/77119609

内容来源于网络，如有侵权，请联系作者删除！

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