itext7学习笔记——第3章实践&example

    本章的例子，请参考我翻译的博文：itext7学习笔记——第3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：撰写日报

    页面划分成三栏，然后添加文本和图片，代码如下：

import com.itextpdf.io.font.FontConstants;import com.itextpdf.io.image.ImageDataFactory;import com.itextpdf.kernel.color.Color;import com.itextpdf.kernel.font.PdfFont;import com.itextpdf.kernel.font.PdfFontFactory;import com.itextpdf.kernel.geom.PageSize;import com.itextpdf.kernel.geom.Rectangle;import com.itextpdf.kernel.pdf.*;import com.itextpdf.layout.ColumnDocumentRenderer;import com.itextpdf.layout.Document;import com.itextpdf.layout.element.*;import java.io.*;import java.nio.charset.StandardCharsets;import java.nio.file.Files;import java.nio.file.Paths;/** * Simple column renderer example. */public class C03E01_NewYorkTimes {    public static final String DEST = "results/chapter03/new_york_times.pdf";    public static final String APPLE_IMG = "src/main/resources/img/ny_times_apple.jpg";    public static final String APPLE_TXT = "src/main/resources/data/ny_times_apple.txt";    public static final String FACEBOOK_IMG = "src/main/resources/img/ny_times_fb.jpg";    public static final String FACEBOOK_TXT = "src/main/resources/data/ny_times_fb.txt";    public static final String INST_IMG = "src/main/resources/img/ny_times_inst.jpg";    public static final String INST_TXT = "src/main/resources/data/ny_times_inst.txt";    static PdfFont timesNewRoman = null;    static PdfFont timesNewRomanBold = null;    public static void main(String[] args) throws Exception {        timesNewRoman = PdfFontFactory.createFont(FontConstants.TIMES_ROMAN);        timesNewRomanBold = PdfFontFactory.createFont(FontConstants.TIMES_BOLD);        File file = new File(DEST);        file.getParentFile().mkdirs();        new C03E01_NewYorkTimes().createPdf(DEST);    }    protected void createPdf(String dest) throws Exception {        //Initialize PDF document        PdfDocument pdf = new PdfDocument(new PdfWriter(dest));        PageSize ps = PageSize.A5;        // Initialize document        Document document = new Document(pdf, ps);        //Set column parameters        float offSet = 36;        float columnWidth = (ps.getWidth() - offSet * 2 + 10) / 3;        float columnHeight = ps.getHeight() - offSet * 2;        //Define column areas        Rectangle[] columns = {new Rectangle(offSet - 5, offSet, columnWidth, columnHeight),                new Rectangle(offSet + columnWidth, offSet, columnWidth, columnHeight),                new Rectangle(offSet + columnWidth * 2 + 5, offSet, columnWidth, columnHeight)};        document.setRenderer(new ColumnDocumentRenderer(document, columns));        Image apple = new Image(ImageDataFactory.create(APPLE_IMG)).setWidth(columnWidth);        String articleApple = new String(Files.readAllBytes(Paths.get(APPLE_TXT)), StandardCharsets.UTF_8);        C03E01_NewYorkTimes.addArticle(document, "Apple Encryption Engineers, if Ordered to Unlock iPhone, Might Resist", "By JOHN MARKOFF MARCH 18, 2016", apple, articleApple);        Image facebook = new Image(ImageDataFactory.create(FACEBOOK_IMG)).setWidth(columnWidth);        String articleFB = new String(Files.readAllBytes(Paths.get(FACEBOOK_TXT)), StandardCharsets.UTF_8);        C03E01_NewYorkTimes.addArticle(document, "With \"Smog Jog\" Through Beijing, Zuckerberg Stirs Debate on Air Pollution", "By PAUL MOZUR MARCH 18, 2016", facebook, articleFB);        Image inst = new Image(ImageDataFactory.create(INST_IMG)).setWidth(columnWidth);        String articleInstagram = new String(Files.readAllBytes(Paths.get(INST_TXT)), StandardCharsets.UTF_8);        C03E01_NewYorkTimes.addArticle(document, "Instagram May Change Your Feed, Personalizing It With an Algorithm","By MIKE ISAAC MARCH 15, 2016", inst, articleInstagram);        document.close();    }    public static void addArticle(Document doc, String title, String author, Image img, String text) throws IOException {        Paragraph p1 = new Paragraph(title)                .setFont(timesNewRomanBold)                .setFontSize(14);        doc.add(p1);        doc.add(img);        Paragraph p2 = new Paragraph()                .setFont(timesNewRoman)                .setFontSize(7)                .setFontColor(Color.GRAY)                .add(author);        doc.add(p2);        Paragraph p3 = new Paragraph()                .setFont(timesNewRoman)                .setFontSize(10)                .add(text);        doc.add(p3);    }}

## 例子2：不一样的表格

    绘制一个表格，第一栏为圆角单元格，每一列的背景颜色不同，根据列号而定，代码如下：

import com.itextpdf.io.font.FontConstants;import com.itextpdf.kernel.color.Color;import com.itextpdf.kernel.color.DeviceCmyk;import com.itextpdf.kernel.font.PdfFont;import com.itextpdf.kernel.font.PdfFontFactory;import com.itextpdf.kernel.geom.PageSize;import com.itextpdf.kernel.geom.Rectangle;import com.itextpdf.kernel.pdf.PdfDocument;import com.itextpdf.kernel.pdf.PdfWriter;import com.itextpdf.kernel.pdf.canvas.PdfCanvas;import com.itextpdf.layout.Document;import com.itextpdf.layout.property.HorizontalAlignment;import com.itextpdf.layout.border.SolidBorder;import com.itextpdf.layout.element.Cell;import com.itextpdf.layout.element.Paragraph;import com.itextpdf.layout.element.Table;import com.itextpdf.layout.property.TextAlignment;import com.itextpdf.layout.renderer.CellRenderer;import com.itextpdf.layout.renderer.DrawContext;import java.io.*;import java.util.StringTokenizer;/** * Simple table renderer example. */public class C03E02_PremierLeague {    public static final String DATA = "src/main/resources/data/premier_league.csv";    public static final String DEST = "results/chapter03/premier_league.pdf";    Color greenColor = new DeviceCmyk(0.78f, 0, 0.81f, 0.21f);    Color yellowColor = new DeviceCmyk(0, 0, 0.76f, 0.01f);    Color redColor = new DeviceCmyk(0, 0.76f, 0.86f, 0.01f);    Color blueColor = new DeviceCmyk(0.28f, 0.11f, 0, 0);    public static void main(String args[]) throws IOException {        File file = new File(DEST);        file.getParentFile().mkdirs();        new C03E02_PremierLeague().createPdf(DEST);    }    public void createPdf(String dest) throws IOException {        //Initialize PDF document        PdfDocument pdf = new PdfDocument(new PdfWriter(dest));        PageSize ps = new PageSize(842, 680);        // Initialize document        Document document = new Document(pdf, ps);        PdfFont font = PdfFontFactory.createFont(FontConstants.HELVETICA);        PdfFont bold = PdfFontFactory.createFont(FontConstants.HELVETICA_BOLD);        Table table = new Table(new float[]{1.5f, 7, 2, 2, 2, 2, 3, 4, 4, 2});        table.setWidthPercent(100)                .setTextAlignment(TextAlignment.CENTER)                .setHorizontalAlignment(HorizontalAlignment.CENTER);        BufferedReader br = new BufferedReader(new FileReader(DATA));        String line = br.readLine();        process(table, line, bold, true);        while ((line = br.readLine()) != null) {            process(table, line, font, false);        }        br.close();        document.add(table);        //Close document        document.close();    }    public void process(Table table, String line, PdfFont font, boolean isHeader) {        StringTokenizer tokenizer = new StringTokenizer(line, ";");        int columnNumber = 0;        while (tokenizer.hasMoreTokens()) {            if (isHeader) {                Cell cell = new Cell().add(new Paragraph(tokenizer.nextToken()));                cell.setNextRenderer(new RoundedCornersCellRenderer(cell));                cell.setPadding(5).setBorder(null);                table.addHeaderCell(cell);            } else {                columnNumber++;                Cell cell = new Cell().add(new Paragraph(tokenizer.nextToken()));                cell.setFont(font).setBorder(new SolidBorder(Color.BLACK, 0.5f));                switch (columnNumber) {                    case 4:                        cell.setBackgroundColor(greenColor);                        break;                    case 5:                        cell.setBackgroundColor(yellowColor);                        break;                    case 6:                        cell.setBackgroundColor(redColor);                        break;                    default:                        cell.setBackgroundColor(blueColor);                        break;                }                table.addCell(cell);            }        }    }    private class RoundedCornersCellRenderer extends CellRenderer {        public RoundedCornersCellRenderer(Cell modelElement) {            super(modelElement);        }        @Override        public void drawBorder(DrawContext drawContext) {            Rectangle rectangle = getOccupiedAreaBBox();            float llx = rectangle.getX() + 1;            float lly = rectangle.getY() + 1;            float urx = rectangle.getX() + getOccupiedAreaBBox().getWidth() - 1;            float ury = rectangle.getY() + getOccupiedAreaBBox().getHeight() - 1;            PdfCanvas canvas = drawContext.getCanvas();            float r = 4;            float b = 0.4477f;            canvas.moveTo(llx, lly).lineTo(urx, lly).lineTo(urx, ury - r)                    .curveTo(urx, ury - r * b, urx - r * b, ury, urx - r, ury)                    .lineTo(llx + r, ury)                    .curveTo(llx + r * b, ury, llx, ury - r * b, llx, ury - r)                    .lineTo(llx, lly).stroke();            super.drawBorder(drawContext);        }    }

## 例子2:添加页眉、页脚和水印

    绘制一个表格，奇偶页背景颜色不同，添加页眉、页脚和水印，代码如下：

import com.itextpdf.io.font.FontConstants;import com.itextpdf.kernel.color.Color;import com.itextpdf.kernel.color.DeviceCmyk;import com.itextpdf.kernel.events.Event;import com.itextpdf.kernel.events.IEventHandler;import com.itextpdf.kernel.events.PdfDocumentEvent;import com.itextpdf.kernel.font.PdfFont;import com.itextpdf.kernel.font.PdfFontFactory;import com.itextpdf.kernel.geom.Rectangle;import com.itextpdf.kernel.pdf.PdfDocument;import com.itextpdf.kernel.pdf.PdfPage;import com.itextpdf.kernel.pdf.PdfWriter;import com.itextpdf.kernel.pdf.canvas.PdfCanvas;import com.itextpdf.layout.Canvas;import com.itextpdf.layout.Document;import com.itextpdf.layout.border.SolidBorder;import com.itextpdf.layout.element.Cell;import com.itextpdf.layout.element.Paragraph;import com.itextpdf.layout.element.Table;import com.itextpdf.layout.property.Property;import com.itextpdf.layout.property.TextAlignment;import com.itextpdf.layout.property.UnitValue;import com.itextpdf.layout.property.VerticalAlignment;import java.io.BufferedReader;import java.io.File;import java.io.FileReader;import java.util.StringTokenizer;/** * Simple event handler example. */public class C03E03_UFO {    public static final String DATA = "src/main/resources/data/ufo.csv";    public static final String DEST = "results/chapter03/ufo.pdf";    static PdfFont helvetica = null;    static PdfFont helveticaBold = null;    public static void main(String[] args) throws Exception {        helvetica = PdfFontFactory.createFont(FontConstants.HELVETICA);        helveticaBold = PdfFontFactory.createFont(FontConstants.HELVETICA_BOLD);        File file = new File(DEST);        file.getParentFile().mkdirs();        new C03E03_UFO().createPdf(DEST);    }    protected void createPdf(String dest) throws Exception {        //Initialize PDF document        PdfDocument pdf = new PdfDocument(new PdfWriter(dest));        pdf.addEventHandler(PdfDocumentEvent.END_PAGE, new MyEventHandler());        // Initialize document        Document document = new Document(pdf);        Paragraph p = new Paragraph("List of reported UFO sightings in 20th century")                .setTextAlignment(TextAlignment.CENTER).setFont(helveticaBold).setFontSize(14);        document.add(p);        Table table = new Table(UnitValue.createPercentArray(new float[]{3, 5, 7, 4}));        BufferedReader br = new BufferedReader(new FileReader(DATA));        String line = br.readLine();        process(table, line, helveticaBold, true);        while ((line = br.readLine()) != null) {            process(table, line, helvetica, false);        }        br.close();        document.add(table);        document.close();    }    public void process(Table table, String line, PdfFont font, boolean isHeader) {        StringTokenizer tokenizer = new StringTokenizer(line, ";");        while (tokenizer.hasMoreTokens()) {            if (isHeader) {                table.addHeaderCell(new Cell().add(new Paragraph(tokenizer.nextToken()).setFont(font)).setFontSize(9).setBorder(new SolidBorder(Color.BLACK, 0.5f)));            } else {                table.addCell(new Cell().add(new Paragraph(tokenizer.nextToken()).setFont(font)).setFontSize(9).setBorder(new SolidBorder(Color.BLACK, 0.5f)));            }        }    }    protected class MyEventHandler implements IEventHandler {        public void handleEvent(Event event) {            PdfDocumentEvent docEvent = (PdfDocumentEvent) event;            PdfDocument pdfDoc = docEvent.getDocument();            PdfPage page = docEvent.getPage();            int pageNumber = pdfDoc.getPageNumber(page);            Rectangle pageSize = page.getPageSize();            PdfCanvas pdfCanvas = new PdfCanvas(page.newContentStreamBefore(), page.getResources(), pdfDoc);            //Set background            Color limeColor = new DeviceCmyk(0.208f, 0, 0.584f, 0);            Color blueColor = new DeviceCmyk(0.445f, 0.0546f, 0, 0.0667f);            pdfCanvas.saveState()                    .setFillColor(pageNumber % 2 == 1 ? limeColor : blueColor)                    .rectangle(pageSize.getLeft(), pageSize.getBottom(), pageSize.getWidth(), pageSize.getHeight())                    .fill().restoreState();            //Add header and footer            pdfCanvas.beginText()                    .setFontAndSize(helvetica, 9)                    .moveText(pageSize.getWidth() / 2 - 60, pageSize.getTop() - 20)                    .showText("THE TRUTH IS OUT THERE")                    .moveText(60, -pageSize.getTop() + 30)                    .showText(String.valueOf(pageNumber))                    .endText();            //Add watermark            Canvas canvas = new Canvas(pdfCanvas, pdfDoc, page.getPageSize());            canvas.setFontColor(Color.WHITE);            canvas.setProperty(Property.FONT_SIZE, 60);            canvas.setProperty(Property.FONT, helveticaBold);            canvas.showTextAligned(new Paragraph("CONFIDENTIAL"), 298, 421, pdfDoc.getPageNumber(page),                    TextAlignment.CENTER, VerticalAlignment.MIDDLE, 45);            pdfCanvas.release();        }    }}

Example代码下载

    本章代码可在如下地址下载（IDEA工程）：iText7——第三章源代码工程