<dependency>

            <groupId>com.itextpdf</groupId>

            <artifactId>itextpdf</artifactId>

            <version>5.5.13</version>

        </dependency>

        <dependency>

            <groupId>org.bouncycastle</groupId>

            <artifactId>bcprov-jdk15on</artifactId>

            <version>1.47</version>

        </dependency>

        <dependency>

            <groupId>org.bouncycastle</groupId>

            <artifactId>bcmail-jdk15on</artifactId>

            <version>1.47</version>

        </dependency>

public static void main(String[] args) throws Exception {

        // 根据页码拆分pdf，有多少页就拆成多少张pdf

        File file = new File("pdf文件绝对路径");

        PdfReader pdfReader = new PdfReader(new FileInputStream(file));

        int pages = pdfReader.getNumberOfPages();

        // 设置日期格式

        SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");

        for (int i = 1; i <= pages; i++) {

            PdfReader reader = new PdfReader("pdf文件绝对路径");

            Document doc = new Document();

            // 每个pdf命名规则：时间戳（2019109143408）+"-"+顺序编号（i）

            String pdfName =  "D:/test/" + df.format(new Date()) + "-" + i + ".pdf";

            PdfWriter writer = PdfWriter.getInstance(doc, new FileOutputStream(pdfName));

            doc.open();

            PdfContentByte cb = writer.getDirectContent();

            doc.newPage();

            cb.addTemplate(writer.getImportedPage(reader, i), 0, 0);

            doc.close();

            writer.close();

            reader.close();

        }

    }