前言：最近要做一个打印机的项目，用户可以上传文件，然后选择打印的页数，所以后端需要对上传的文件进行解析获取页数。
Maven项目直接先上pom
<dependencies><dependency><groupId>com.itextpdf</groupId><artifactId>itextpdf</artifactId><version>5.0.6</version></dependency><!-- /artifact/org.apache.poi/poi --><dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>4.1.2</version></dependency><!-- /artifact/org.apache.poi/poi-ooxml --><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>4.1.2</version></dependency><!-- /artifact/org.apache.poi/poi-scratchpad --><dependency><groupId>org.apache.poi</groupId><artifactId>poi-scratchpad</artifactId><version>4.1.2</version></dependency></dependencies>
首先，现在的后端都是SpringBoot项目，都是用MultipartFile对象接收文件，默认上传大小好像是1MB，如果文件大的话可以设置上传大小，不然会报错org.apache.tomcat.util.http.fileupload.impl.SizeLimitExceededException: the request was rejected because its size (4543309) exceeds the configured maximum (1048576)
设置方法为在yml配置文件添加配置：
spring: servlet:multipart:max-file-size: 100MBmax-request-size: 100MBenabled: true
第二步、因为word、pdf、ppt获取页数的方法都不一样，所以先通过后缀获取文件类型
String fileName = file.getOriginalFilename(); //获取文件名String type = fileName.substring(fileName.lastIndexOf(".")); 获取后缀
第三步，将MultipartFile转成InputStream流的形式进行解析
MultipartFile转成InputStream的方法：MultipartFile file；byte[] byteArr = file.getBytes();InputStream inputStream = new ByteArrayInputStream(byteArr);
第四步：因为经常要用到获取页数的方法，所以我直接写了一个工具类，大家可以直接复制；
public class FilePagesUtils {/*** * @param fileInputStream 文件流* @param fileType 文件后缀* @return* @throws IOException*/public static int filesPage(InputStream fileInputStream, String fileType) throws IOException {int count = 0;if (".doc".equals(fileType)) {count = countWordPage(fileInputStream);}if (".docx".equals(fileType)) {count = countWordPage(fileInputStream);}if (".pdf".equals(fileType)) {count = countPdfPage(fileInputStream);}if (".pptx".equals(fileType)) {count = countPPTXPage(fileInputStream);}if (".ppt".equals(fileType)) {count = countPPTPage(fileInputStream);}return count;}/*** 计算PDF格式文档的页数*/public static int countPdfPage(InputStream fileInputStream) {int pageCount = 0;PdfReader reader = null;try {reader = new PdfReader(fileInputStream);pageCount = reader.getNumberOfPages();} catch (IOException e) {e.printStackTrace();} finally {reader.close();}return pageCount;}/*** 计算PPTX格式文档的页数* @param fileInputStream* @return* @throws IOException*/public static int countPPTPage(InputStream fileInputStream) throws IOException {int pageCount = 0;ZipSecureFile.setMinInflateRatio(-1.0d);HSLFSlideShow hslfSlideShow = new HSLFSlideShow(fileInputStream);try {pageCount = hslfSlideShow.getSlides().size();} catch (Exception e) {e.printStackTrace();} finally {fileInputStream.close();}return pageCount;}/*** 计算PPTX格式文档的页数*/public static int countPPTXPage(InputStream fileInputStream) throws IOException {int pageCount = 0;ZipSecureFile.setMinInflateRatio(-1.0d);try {XMLSlideShow pptxFile = new XMLSlideShow(fileInputStream);pageCount = pptxFile.getSlides().size();} catch (IOException e) {e.printStackTrace();} finally {fileInputStream.close();}return pageCount;}/*** 计算WORD(*.docx)格式文档的页数*/public static int countWordPage(InputStream fileInputStream) throws IOException {int pageCount = 0;ZipSecureFile.setMinInflateRatio(-1.0d);XWPFDocument docx = null;try {docx = new XWPFDocument(fileInputStream);pageCount = docx.getProperties().getExtendedProperties().getUnderlyingProperties().getPages();//总页数} catch (IOException e) {e.printStackTrace();} finally {docx.close();}return pageCount;}/*** 计算WORD(*.doc)格式文档的页数*/public static int countWordPage(InputStream fileInputStream) throws IOException {int pageCount = 0;WordExtractor doc = null;ZipSecureFile.setMinInflateRatio(-1.0d);try {doc = new WordExtractor(fileInputStream);//.doc格式Word文件提取器pageCount = doc.getSummaryInformation().getPageCount();//总页数} catch (IOException e) {e.printStackTrace();} finally {doc.close();}return pageCount;}}
