[Java 17] 无模版动态生成 PDF:图片嵌入与动态表格渲染实战

发布于:2025-07-15 ⋅ 阅读:(16) ⋅ 点赞:(0)

实现效果

在这里插入图片描述

引言

在企业开发中,动态生成 PDF(如出库单、发票)是常见需求。传统方法依赖模板,灵活性不足。本文将展示如何使用 Java 17 结合 iTextPDF 和 ZXing 库,实现在无模版情况下动态生成 PDF,嵌入 logo、渲染动态表格并添加二维码和水印。文章提供完整 demo 代码和开发经验分享。

技术要点

  1. 无模版生成:无需预设模板,纯代码构建。
  2. 图片嵌入:添加 logo 等图像。
  3. 动态表格渲染:根据数据动态生成多列表格。
  4. Java 17 环境:使用现代 Java 版本。
  5. 依赖管理:通过 Maven 配置 iTextPDF 和 ZXing。

实现步骤

1. 环境准备

使用 Java 17,依赖通过 Maven 管理。以下是 pom.xml 文件:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>untitled</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itextpdf</artifactId>
            <version>5.5.13</version>
        </dependency>
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itext-asian</artifactId>
            <version>5.2.0</version>
        </dependency>
        <dependency>
            <groupId>com.itextpdf.tool</groupId>
            <artifactId>xmlworker</artifactId>
            <version>5.5.13.3</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.5.1</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>javase</artifactId>
            <version>3.3.0</version>
        </dependency>
    </dependencies>
</project>

运行 mvn clean install 安装依赖。

2. 代码实现

2.1 左上角添加 logo

添加 logo 图片到 PDF 左上角:

    private static void addLogo(Document document, PdfWriter writer) throws DocumentException, IOException {
        // 替换为实际 logo 图片路径,例如 "src/main/resources/logo.jpeg"
        Image logo = Image.getInstance("src/main/resources/logo.jpeg");
        logo.scaleToFit(100, 100); // 调整 logo 大小

        logo.setAlignment(Image.ALIGN_LEFT);
        document.add(logo); // 使用文档流插入

    }

在这里插入图片描述

	好吧,其实并不是这样的logo,往下慢慢看吧。
2.2 添加可见标题

在文档顶部添加居中标题:

    private static void addDocumentTitle(Document document) throws DocumentException, IOException {
        BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
        Font titleFont = new Font(bfChinese, 20, Font.BOLD);
        Paragraph title = new Paragraph("出库单", titleFont);
        title.setAlignment(Element.ALIGN_CENTER);
//        title.setSpacingBefore(5f);
//        title.setSpacingAfter(5f);
        document.add(title);
    }
2.3 基础单据信息

使用 4 列表格展示基础信息,动态从 API 数据填充:

// 添加基础单据信息 (4列布局,增加间距)
private static void addBasicInfo(Document document) throws DocumentException, IOException {
    PdfPTable table = new PdfPTable(4);
    table.setWidthPercentage(100);
    table.setSpacingBefore(150f);
    table.setSpacingAfter(50f);

    BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
    Font headerFont = new Font(bfChinese, 14, Font.BOLD);
    Font contentFont = new Font(bfChinese, 14);

    Map<String, String> apiData = getBaseInfoFromApi();

    List<String> keys = new ArrayList<>(fieldNameToLabelMap.keySet());
    for (int i = 0; i < keys.size(); i += 2) {
        String key1 = keys.get(i);
        String key2 = (i + 1 < keys.size()) ? keys.get(i + 1) : "";
        String label1 = fieldNameToLabelMap.get(key1);
        String value1 = apiData.getOrDefault(key1, "");
        String label2 = key2.isEmpty() ? "" : fieldNameToLabelMap.get(key2);
        String value2 = key2.isEmpty() ? "" : apiData.getOrDefault(key2, "");
        addInfoRow(table, label1, value1, label2, value2, headerFont, contentFont);
    }

    document.add(table);
}
    // 工具方法:添加单行 (4列)
private static void addInfoRow(PdfPTable table, String key1, String value1, String key2, String value2, Font keyFont, Font valueFont) {
    PdfPCell keyCell1 = new PdfPCell(new Phrase(key1, keyFont));
    keyCell1.setHorizontalAlignment(Element.ALIGN_LEFT);
    keyCell1.setBorderWidth(0.5f);
    keyCell1.setPadding(10f);
    keyCell1.setMinimumHeight(25f);

    PdfPCell valueCell1 = new PdfPCell(new Phrase(value1, valueFont));
    valueCell1.setHorizontalAlignment(Element.ALIGN_LEFT);
    valueCell1.setBorderWidth(0.5f);
    valueCell1.setPadding(10f);
    valueCell1.setMinimumHeight(25f);

    PdfPCell keyCell2 = new PdfPCell(new Phrase(key2, keyFont));
    keyCell2.setHorizontalAlignment(Element.ALIGN_LEFT);
    keyCell2.setBorderWidth(0.5f);
    keyCell2.setPadding(10f);
    keyCell2.setMinimumHeight(25f);

    PdfPCell valueCell2 = new PdfPCell(new Phrase(value2, valueFont));
    valueCell2.setHorizontalAlignment(Element.ALIGN_LEFT);
    valueCell2.setBorderWidth(0.5f);
    valueCell2.setPadding(10f);
    valueCell2.setMinimumHeight(25f);

    table.addCell(keyCell1);
    table.addCell(valueCell1);
    table.addCell(keyCell2);
    table.addCell(valueCell2);
}
2.4 动态表格渲染

动态生成出库单明细表格:

private static void addOutboundDetails(Document document) throws DocumentException, IOException {
        // 模拟从接口获取的动态数据
        List<OutboundDetail> details = generateSampleDetails();

        // 创建表格 (7列: 序号, 订单号, 订单明细号, 产品名称, 单位, 数量, 单价)
        PdfPTable table = new PdfPTable(7);
        table.setWidthPercentage(100);
        table.setSpacingBefore(50f); // 增加间距,向下移动以避免被上部内容覆盖

        // 使用支持中文的字体
        BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
        Font headerFont = new Font(bfChinese, 12, Font.BOLD);
        Font contentFont = new Font(bfChinese, 12);

        // 表头
        addTableHeader(table, headerFont);

        // 动态添加数据
        for (int i = 0; i < details.size(); i++) {
            OutboundDetail detail = details.get(i);
            table.addCell(createCell(String.valueOf(i + 1), contentFont));
            table.addCell(createCell(detail.getOrderId(), contentFont));
            table.addCell(createCell(detail.getDetailId(), contentFont));
            table.addCell(createCell(detail.getProductName(), contentFont));
            table.addCell(createCell(detail.getUnit(), contentFont));
            table.addCell(createCell(String.valueOf(detail.getQuantity()), contentFont));
            table.addCell(createCell(String.format("%.2f", detail.getUnitPrice()), contentFont));
        }

        document.add(table);
    }




    // 添加表格表头
    private static void addTableHeader(PdfPTable table, Font font) {
        String[] headers = {"序号", "订单号", "订单明细号", "产品名称", "单位", "数量", "单价"};
        for (String header : headers) {
            PdfPCell cell = new PdfPCell(new Phrase(header, font));
            cell.setHorizontalAlignment(Element.ALIGN_CENTER);
            cell.setBackgroundColor(BaseColor.LIGHT_GRAY);
            cell.setMinimumHeight(25f);
            table.addCell(cell);
        }
    }

    // 创建单元格
    private static PdfPCell createCell(String content, Font font) {
        PdfPCell cell = new PdfPCell(new Phrase(content, font));
        cell.setHorizontalAlignment(Element.ALIGN_CENTER);
        cell.setBorderWidth(0.5f);
        cell.setMinimumHeight(25f);
        cell.setPadding(8f);
        return cell;
    }
2.5 二维码区域

在右上角添加二维码:

private static void addQRCodePlaceholder(Document document, PdfWriter writer) throws DocumentException {
        try {
            // 获取第一个订单信息作为二维码内容
            List<OutboundDetail> details = generateSampleDetails();
            if (!details.isEmpty()) {
                OutboundDetail detail = details.get(0);
                String qrContent = "OrderID: " + detail.getOrderId() + "\nUnitPrice: " + detail.getUnitPrice() +
                        "\nQuantity: " + detail.getQuantity() + "\nDate: 2025-07-10";

                // 生成二维码图像
                int size = 100;
                BitMatrix bitMatrix = new MultiFormatWriter().encode(qrContent, BarcodeFormat.QR_CODE, size, size);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                MatrixToImageWriter.writeToStream(bitMatrix, "png", baos);
                Image qrImage = Image.getInstance(baos.toByteArray());
                qrImage.scaleToFit(size, size);

                // 设置二维码位置 —— 保持原有位置
                float x = PageSize.A4.getWidth() - size - 10f;
                float y = PageSize.A4.getHeight() - qrImage.getScaledHeight() - 10f;
                qrImage.setAbsolutePosition(x, y);

                writer.getDirectContent().addImage(qrImage);
            } else {
                Paragraph qr = new Paragraph();
                qr.add(new Chunk("二维码区域 (无数据)\n", FontFactory.getFont(FontFactory.HELVETICA, 14, Font.BOLD)));
                qr.setAlignment(Element.ALIGN_RIGHT);
                document.add(qr);
            }
        } catch (Exception e) {
            e.printStackTrace();
            Paragraph qr = new Paragraph();
            qr.add(new Chunk("二维码区域 (生成失败)\n", FontFactory.getFont(FontFactory.HELVETICA, 14, Font.BOLD)));
            qr.setAlignment(Element.ALIGN_RIGHT);
            document.add(qr);
        }
    }
2.6 添加水印

在 PDF 背景添加倾斜水印:

private static void addTextWatermark(PdfWriter writer, String watermarkText) throws IOException, DocumentException {
        PdfContentByte under = writer.getDirectContentUnder();

        // 设置字体
        BaseFont baseFont = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
        under.saveState();

        // 设置透明度
        PdfGState gs1 = new PdfGState();
        gs1.setFillOpacity(0.1f); // 越小越淡
        under.setGState(gs1);

        // 设置字体大小和颜色
        under.beginText();
        under.setFontAndSize(baseFont, 60); // 字体大小
        under.setColorFill(BaseColor.LIGHT_GRAY);

        // 页面宽高
        float pageWidth = PageSize.A4.getWidth();
        float pageHeight = PageSize.A4.getHeight();

        // 网格循环:每隔一定间距绘制一行水印(x 横向,y 纵向)
        for (float x = -100; x < pageWidth + 100; x += 200) {
            for (float y = -100; y < pageHeight + 100; y += 150) {
                under.showTextAligned(Element.ALIGN_CENTER, watermarkText, x, y, 45); // 倾斜 45 度
            }
        }

        under.endText();
        under.restoreState();
    }

}
2.7 辅助类和数据

数据模型和模拟 API 数据,包括 fieldNameToLabelMap 初始化:

static class OutboundDetail {
    private String orderId;
    private String detailId;
    private String productName;
    private String unit;
    private double quantity;
    private double unitPrice;

    public OutboundDetail(String orderId, String detailId, String productName, String unit, double quantity, double unitPrice) {
        this.orderId = orderId;
        this.detailId = detailId;
        this.productName = productName;
        this.unit = unit;
        this.quantity = quantity;
        this.unitPrice = unitPrice;
    }

    public String getOrderId() { return orderId; }
    public String getDetailId() { return detailId; }
    public String getProductName() { return productName; }
    public String getUnit() { return unit; }
    public double getQuantity() { return quantity; }
    public double getUnitPrice() { return unitPrice; }
}

private static final Map<String, String> fieldNameToLabelMap = new LinkedHashMap<>();

static {
    fieldNameToLabelMap.put("orderCode", "单据编号");
    fieldNameToLabelMap.put("outboundDate", "出库日期");
    fieldNameToLabelMap.put("customerName", "客户名称");
    fieldNameToLabelMap.put("warehouseCode", "仓库编号");
    fieldNameToLabelMap.put("creator", "制单人");
    fieldNameToLabelMap.put("auditor", "审核人");
    fieldNameToLabelMap.put("createTime", "制单时间");
    fieldNameToLabelMap.put("outboundOrderId", "出库单据ID");
}

private static Map<String, String> getBaseInfoFromApi() {
    Map<String, String> data = new HashMap<>();
    data.put("orderCode", "BF-03-05-1");
    data.put("outboundDate", "2025-06-04");
    data.put("customerName", "某某公司");
    data.put("warehouseCode", "CK_7525080416537318");
    data.put("creator", "张三");
    data.put("auditor", "李四");
    data.put("createTime", "2025-06-04 16:15:48");
    data.put("outboundOrderId", "13500135000");
    return data;
}

private static List<OutboundDetail> generateSampleDetails() {
    List<OutboundDetail> details = new ArrayList<>();
    details.add(new OutboundDetail("BF-03-05-1", "no1", "34CrNiMo6", "原材料", 6.60, 100.00));
    details.add(new OutboundDetail("BF-03-05-2", "no2", "35CrMo", "半成品", 5.5, 120.00));
    details.add(new OutboundDetail("BF-03-05-3", "no3", "Q235", "成品", 10.0, 80.00));
    return details;
}

public static void main(String[] args) {
    try {
        Document document = new Document(PageSize.A4);
        PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("outbound_document.pdf"));
        document.open();

        addLogo(document, writer);
        addDocumentTitle(document);
        addBasicInfo(document);
        addOutboundDetails(document);
        addQRCodePlaceholder(document, writer);
        addTextWatermark(writer, "ikun");

        document.close();
        System.out.println("PDF 生成成功!文件位置: outbound_document.pdf");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

3. 开发中的调整经验

开发初期,我将二维码位置使用 setAbsolutePosition 固定在右上角(例如 x = PageSize.A4.getWidth() - 100f, y = PageSize.A4.getHeight() - 100f),导致基础信息表格始终被覆盖。问题出在绝对定位与文档流冲突上。调整过程:

  • 增加间距:将 addBasicInfo 中的 setSpacingBefore 从 50f 调整到 150f,确保表格向下移动。
  • 动态布局:改为使用 document.add() 添加元素,避免固定位置重叠。
  • 调试优化:通过生成 PDF 逐一检查布局,逐步调整 setSpacingBefore 值(例如增至 100f 或 150f),确保内容可见。

4. 运行与测试

  • logo.jpeg 放入 src/main/resources/ 目录。
  • 运行 main 方法,生成 outbound_document.pdf
  • 检查 PDF 是否包含 logo、标题、基础信息表格、动态表格、二维码和水印。

注意事项

  • 图片路径:确保 logo.jpeg 路径正确。
  • 字体支持:依赖 itext-asian,若字体加载失败,可替换为本地字体(如 SimSun.ttf)。
  • 依赖冲突:若版本冲突,调整 pom.xml 中的依赖版本。
    在这里插入图片描述

总结

本文通过 Java 17 实现了无模版动态生成 PDF,结合 iTextPDF 嵌入图片和渲染动态表格,ZXing 生成二维码,并添加水印。完整 demo 代码提供参考,开发中通过调整间距解决了布局冲突问题。欢迎评论区交流优化建议!

作者@Brain

demo:代码请见gitee



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