java 合并Pdf

<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>pdfbox</artifactId>
    <version>2.0.20</version>
</dependency>

import org.apache.pdfbox.io.MemoryUsageSetting;
import org.apache.pdfbox.multipdf.PDFMergerUtility;

/**
 * 合并Pdf文件
 *
 * @param destFilePath
 * @param files
 * @param userTempFolder
 */
private void mergeFile(String destFilePath, List<String> files, String userTempFolder) {
    // pdf合并工具类
    PDFMergerUtility mergePdf = new PDFMergerUtility();
    for (String item : files) {
        // 合成文件
        try {
            mergePdf.addSource(userTempFolder + "/" + item);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    // 设置合并生成pdf文件
    mergePdf.setDestinationFileName(destFilePath);
    // 合并pdf
    try {
        mergePdf.mergeDocuments(MemoryUsageSetting.setupMainMemoryOnly());
    } catch (Exception e) {
        System.out.println("pdf文件合并失败");
        e.printStackTrace();
    }
    System.out.println("pdf文件合并成功");
}