合并多個PDF為一個PDF

1.導入依賴
      

<dependency>
   <groupId>org.apache.pdfbox</groupId>
   <artifactId>pdfbox</artifactId>
   <version>2.0.16</version>
</dependency>

<dependency>
   <groupId>org.apache.pdfbox</groupId>
   <artifactId>pdfbox-tools</artifactId>
   <version>2.0.16</version>
</dependency>      

2.工具類
public class PDFUtils {      

public static void main(String[] args)  throws Exception{
        Long s = System.currentTimeMillis();
//        System.out.println(pdfToImage("d:/3333.pdf"));
        List<String> pdfList = new ArrayList<>();
        pdfList.add("d:/3333.pdf");
        pdfList.add("d:/3333.pdf");
        pdfList.add("d:/3333.pdf");
        pdfList.add("d:/3333.pdf");
        pdfList.add("d:/3333.pdf");
        String save = "d:/hb.pdf";
        mergePDF(pdfList,save);
        File f = new File(save);
        System.out.println(f.exists());
        System.out.println(System.currentTimeMillis()-s);
    }

    /**
     * 合并多個PDF為一個PDF
     * @param pdfList   PDF檔案清單
     * @param mergePDFPath  合并後的PDF完整路徑
     */
    public static void mergePDF(List<String> pdfList,String mergePDFPath){
        try {
            PDFMergerUtility PDFmerger = new PDFMergerUtility();
            PDFmerger.setDestinationFileName(mergePDFPath);
            for(String str :pdfList) {
                File file = new File(str);
                PDFmerger.addSource(file);
            }
            PDFmerger.mergeDocuments(MemoryUsageSetting.setupMainMemoryOnly());
            log.info(pdfList.size()+"個PDF合并成功");
        }catch (Exception e){
            e.printStackTrace();
        }
    }      

}