itextpdf 7生成pdf(主要是文字和表格，支持中文)-编程知识

我们经常会遇到要导出pdf的需求,方式有很多种今天的教程是采用itextpdf的方式生成pdf
itextpdf是用于生成PDF文档的一个java类库。通过iText不仅可以生成PDF文档，而且可以将Html文件转化为PDF文件。

这里先展示一下效果图
测试pdf效果图

首先在pom.xml中引入相关依赖

<dependencys><!-- itext7 --><dependency><groupId>com.itextpdf</groupId><artifactId>itext7-core</artifactId><version>7.2.1</version><type>pom</type></dependency><dependency><groupId>com.itextpdf</groupId><artifactId>pdftest</artifactId><version>7.1.16</version><scope>test</scope></dependency>
</dependencys>

PdfUtil 工具类

创建pdf、获取字体
如果需要添加水印，可以自行修改对应的图片路径(static/logo.png)
其中用到的字体文件在这里下载

package com.***.utils.pdf;import com.itextpdf.io.font.PdfEncodings;
import com.itextpdf.io.image.ImageData;
import com.itextpdf.io.image.ImageDataFactory;
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.kernel.pdf.canvas.PdfCanvas;
import com.itextpdf.kernel.pdf.extgstate.PdfExtGState;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Cell;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.properties.TextAlignment;
import com.itextpdf.layout.properties.UnitValue;
import com.itextpdf.layout.properties.VerticalAlignment;import java.io.FileNotFoundException;
import java.io.IOException;public class PdfUtil {static final String LOGO_TEXT = "";/*** 给pdf 添加水印** @param doc Document 对象* @throws Exception*/public static void generateWatermark(Document doc) throws Exception {
//        PdfDocument pdfDoc = new PdfDocument(new PdfReader(fis), new PdfWriter(fos));
//        Document doc = new Document(pdfDoc);
//        PdfFont font = PdfFontFactory.createFont("STSong-Light", "UniGB-UCS2-H");PdfDocument pdfDoc = doc.getPdfDocument();// 将字体包拖到路径下PdfFont pdfFont = getZhFont();Paragraph paragraph = new Paragraph(LOGO_TEXT).setFont(pdfFont).setFontSize(14);ImageData img = ImageDataFactory.create(PdfUtil.class.getClassLoader().getResource("static/logo.png"));float w = img.getWidth();float h = img.getHeight();PdfExtGState gs1 = new PdfExtGState().setFillOpacity(0.1f);for (int i = 1; i <= pdfDoc.getNumberOfPages(); i++) {PdfPage pdfPage = pdfDoc.getPage(i);Rectangle pageSize = pdfPage.getPageSizeWithRotation();pdfPage.setIgnorePageRotationForContent(true);PdfCanvas over = new PdfCanvas(pdfDoc.getPage(i));over.saveState();over.setExtGState(gs1);float x = pageSize.getX();float y = pageSize.getY();float pageWidth = pageSize.getWidth();float pageHeight = pageSize.getHeight();while (y < pageHeight) {if (y == 0) y = y + 10;while (x < pageWidth) {
//                    if(x==0) x = x+48;if (x == 0) x = x + 68;over.addImageWithTransformationMatrix(img, w / 2, 0, 0, h / 2, x, y, false);
//                    doc.showTextAligned(paragraph, x+32, y+38, i, TextAlignment.LEFT, VerticalAlignment.TOP, 0.3f);x = x + 180;}x = pageSize.getX();y = y + 120;}over.restoreState();}
//        doc.close();}/*** 获取中文字体** @return* @throws IOException*/public static PdfFont getZhFont() throws IOException {return PdfFontFactory.createFont(PdfUtil.class.getClassLoader().getResource("static/msyh.ttf").toString(),PdfEncodings.IDENTITY_H);}/*** 获得一个 PDF table cell** @param txt text* @param v   最大宽度百分比* @return*/public static Cell newPdfCell(String txt, float v) {return new Cell().add(new Paragraph(txt).setTextAlignment(TextAlignment.CENTER)).setVerticalAlignment(VerticalAlignment.MIDDLE).setMaxWidth(UnitValue.createPercentValue(v));}/*** 新建 pdfDoc** @param pdfPath  pdfPath* @param fileName 文件名* @return* @throws FileNotFoundException*/public static Document newPdfDoc(String pdfPath, String fileName) throws FileNotFoundException {String filePath = pdfPath + fileName;// pdf加密// PdfWriter writer = new PdfWriter(filePath, new WriterProperties().setStandardEncryption(null, "Hz123456".getBytes(), EncryptionConstants.ALLOW_SCREENREADERS,//         EncryptionConstants.ENCRYPTION_AES_128));PdfWriter writer = new PdfWriter(filePath);PdfDocument pdf = new PdfDocument(writer);pdf.setDefaultPageSize(PageSize.A4);return new Document(pdf);}}

TableBuilder 工具类

用于构建pdf中用到的表格

package com.***.pdf;import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.layout.element.Table;
import com.itextpdf.layout.properties.TextAlignment;
import com.itextpdf.layout.properties.UnitValue;
import com.itextpdf.layout.properties.VerticalAlignment;
import lombok.Data;import java.util.List;@Data
public class TableBuilder {/*** pdf表格对象*/Table table;/*** 表格列数*/Integer column;/*** 每列宽度百分比*/Float columnWidthPercent;/*** 创建表格** @param column  列数* @param pdfFont 字体* @return*/public static TableBuilder builder(int column, PdfFont pdfFont) {TableBuilder tableBuilder = new TableBuilder();tableBuilder.setColumn(column);tableBuilder.setColumnWidthPercent(100f / column);float[] values = new float[column];for (int i = 0; i < column; i++) {values[i] = 3;}Table table = new Table(UnitValue.createPercentArray(values))// 这里是设置表格占整个pdf的宽度百分比，这里设置的是100%.setWidth(UnitValue.createPercentValue(100)).setTextAlignment(TextAlignment.CENTER).setVerticalAlignment(VerticalAlignment.MIDDLE)// 设置字体.setFont(pdfFont)// 设置字体大小.setFontSize(10);tableBuilder.setTable(table);return tableBuilder;}// 这里添加数据时，需要注意，每一行的数据个数必须与表格列数一致，单元格无数据时，添加空字符串/*** 添加一行数据* @param row 一行数据* @return*/public TableBuilder addRow(List<String> row) {for (String item : row) {this.table.addCell(PdfUtil.newPdfCell(item, this.columnWidthPercent));}return this;}/*** 添加多行数据* @param rowList 多行数据* @return*/public TableBuilder addRows(List<List<String>> rowList) {for (List<String> row : rowList) {this.addRow(row);}return this;}/*** 获取表格对象* @return*/public Table build() {return this.table;}}

使用以上工具类构建一个测试的pdf，测试pdf效果在文章开头查看

package com.***;import com.***.utils.pdf.PdfUtil;
import com.***.utils.pdf.TableBuilder;
import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Div;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Table;
import com.itextpdf.layout.properties.HorizontalAlignment;
import com.itextpdf.layout.properties.TextAlignment;
import com.itextpdf.layout.properties.UnitValue;
import org.junit.jupiter.api.Test;import java.io.IOException;
import java.util.Arrays;
import java.util.List;public class PdfTest {@Testpublic void testPdf() throws IOException {Document document = PdfUtil.newPdfDoc("/Desktop/", "test.pdf");// 这里的字体对象一个pdf用一次，不能重复(多个pdf)使用，否则会报错PdfFont pdfFont = PdfUtil.getZhFont();Div head1Div = new Div().setWidth(UnitValue.createPercentValue(100)).setHeight(UnitValue.createPercentValue(100)).setHorizontalAlignment(HorizontalAlignment.CENTER);// 标题，22号字体，居中对齐，加粗Paragraph title = new Paragraph("测试pdf标题").setFont(pdfFont).setFontSize(22).setHorizontalAlignment(HorizontalAlignment.CENTER).setTextAlignment(TextAlignment.CENTER).setBold();head1Div.add(title);head1Div.add(new Paragraph("一、第一部分：测试表格").setFont(pdfFont).setFontSize(16).setBold());List<String> header = Arrays.asList("姓名", "年龄", "性别", "手机号", "邮箱", "地址", "职业", "备注");List<List<String>> data = Arrays.asList(Arrays.asList("张三", "25", "男", "13812345678", "zhangsan@qq.com", "北京市海淀区", "学生", "无"),Arrays.asList("王五", "28", "男", "13812345680", "wangwu@qq.com", "广东省深圳市", "律师", "无"));// 表格，8列，字体为pdfFontTable table = TableBuilder.builder(8, pdfFont).addRow(header).addRows(data).build();head1Div.add(table);document.add(head1Div);document.close();}}