documents4j 是一个 Java 库，可以将文档转换为另一种文档格式。

https://github.com/documents4j/documents4j

<parent><artifactId>spring-boot-starter-parent</artifactId><groupId>org.springframework.boot</groupId><version>2.6.0</version>
</parent><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.documents4j</groupId><artifactId>documents4j-local</artifactId><version>1.1.5</version></dependency><dependency><groupId>com.documents4j</groupId><artifactId>documents4j-transformer-msoffice-word</artifactId><version>1.1.5</version></dependency>
</dependencies>

@RequestMapping("/to")
@RestController
public class PdfController {/*** doc文件转pdf** @param path 文件路径*/@RequestMapping("/doc2pdf")public ResponseEntity<byte[]> doc2pdfFileUpload(String path) throws IOException {URL url = new URL(path);URLConnection conn = url.openConnection();InputStream inputStream = conn.getInputStream();return doc2Pdf(inputStream, ".doc", "fileName.pdf");}/*** docx、xlsx、转pdf** @param fileType docx、doc、xls、xlsx* @param fileName pdf名称*/public ResponseEntity<byte[]> doc2Pdf(InputStream docxInputStream, String fileType, String fileName) throws IOException {// 转换后的pdf临时路径File outputFile = new File("C:/Users/admin002/Desktop/folder/doc/" + fileName);IConverter converter = LocalConverter.builder().build();ResponseEntity<byte[]> fileResult = null;try (OutputStream outputStream = Files.newOutputStream(outputFile.toPath());// 导出pdf文件给前端FileInputStream inputStream = new FileInputStream(outputFile);) {if (".docx".equals(fileType)) {converter.convert(docxInputStream).as(DocumentType.DOCX).to(outputStream).as(DocumentType.PDF).execute();} else if (".doc".equals(fileType)) {converter.convert(docxInputStream).as(DocumentType.DOC).to(outputStream).as(DocumentType.PDF).execute();} else if (".xls".equals(fileType)) {converter.convert(docxInputStream).as(DocumentType.XLS).to(outputStream).as(DocumentType.PDF).execute();} else if (".xlsx".equals(fileType)) {converter.convert(docxInputStream).as(DocumentType.XLSX).to(outputStream).as(DocumentType.PDF).execute();}byte[] bytes = new byte[(int) outputFile.length()];inputStream.read(bytes);HttpHeaders headers = new HttpHeaders();// 此处pdf名称需要传入headers.set("Content-Disposition", "attachment; filename=\"" + fileName + "\"");fileResult = new ResponseEntity(bytes, headers, HttpStatus.OK);} finally {docxInputStream.close();}return fileResult;}}

以上方式依赖于Windows上的MS Word、MS Excel，必须使用Windows。

只有在以下情况下才能运行 LocalConverter构建：

• JVM在MS Windows平台上运行，该平台附带VBS的Microsoft脚本主机。
• MS Word 版本必须在2007 或更高版本。安装了 PDF 插件时，才支持 PDF 转换。该插件包含在了Word 2010及更高版本的MS Word中。

未完待续。。。。