如果使用poi直接将所有图片一张张写到excel里，最后excel里图片达到10000张之后，内存就快爆掉了，所以，使用该方法将图片写到磁盘里，最后一次性替换掉，目前没有找到更好的方法，暂时使用该方法试试看
一共有六个步骤
思路是：excel文件本身也跟zip压缩文件类似，我就将其该名为zip文件，再将其解压，找到压缩文件固定存储路径，将原图替换占位图
1.修改名称
2.解压文件
3.图片替换
4.文件压缩
5.修改名称
6.删除缓存文件
import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.*;import java.nio.charset.Charset;import java.util.ArrayList;import java.util.Arrays;import java.util.Date;import java.util.List;import java.util.zip.ZipEntry;import java.util.zip.ZipInputStream;import java.util.zip.ZipOutputStream;public class ExcelFileUtils {private byte[] buf = new byte[1024];private Logger logger = LoggerFactory.getLogger(ExcelFileUtils.class);public static void main(String[] args) throws Exception {ExcelFileUtils excelTest = new ExcelFileUtils();String out = excelTest.excelImageReplace("D:\\workPlace\\java\\BeiShi\\测试Excel\\测试案例\\1673838522783.xlsx","D:\\workPlace\\java\\BeiShi\\测试Excel\\测试案例\\image");System.out.println(out);}public String excelImageReplace(String originFile,String imageDirecytory) throws IOException {ExcelFileUtils excelTest = new ExcelFileUtils();String localPath = originFile.substring(0,originFile.lastIndexOf(File.separator)+1);//1.修改名称String reName = originFile.substring(0,originFile.lastIndexOf(".")+1)+"zip";excelTest.rename(originFile,reName);//2.解压文件//文件解压路径String zipFile = localPath + new Date().getTime()+File.separator;excelTest.unzipFile(reName,zipFile);//3.图片替换String imageFileDirectory = zipFile+"xl"+File.separator+"media"+File.separator;File imageFile = new File(imageFileDirectory);if (!(imageFile.exists()&&imageFile.isDirectory())){logger.error("文件解压异常，excel重新编辑失败");}//清空原文件夹内图片List<String> renameList = new ArrayList<>();for (File file : imageFile.listFiles()) {file.delete();renameList.add(file.getAbsolutePath());}//将图片移动到该文件夹内File imageDirecytoryFile = new File(imageDirecytory);List<File> imageList = Arrays.asList(imageDirecytoryFile.listFiles());for (int i = 0; i < renameList.size(); i++) {String rename = renameList.get(i);File image = imageList.get(i);image.renameTo(new File(rename));}//4.文件压缩String zipOutName = localPath+ new Date().getTime()+".zip";File zipDir = new File(zipFile);excelTest.toZip(zipOutName,Arrays.asList(zipDir.listFiles()));//5.修改名称String xlsxOutName = zipOutName.substring(0,zipOutName.lastIndexOf(".")+1)+"xlsx";excelTest.rename(zipOutName,xlsxOutName);//6.删除缓存文件excelTest.deleteFolder(imageDirecytory);excelTest.deleteFolder(zipFile);new File(reName).delete();zipDir.delete();return xlsxOutName;}//删除文件夹public void deleteFolder(String fileName){File file = new File(fileName);if (!file.isDirectory()){file.delete();}else {for (File listFile : file.listFiles()) {deleteFolder(listFile.getAbsolutePath());}file.delete();}}public Boolean rename(String path/*原文件路径+文件名*/, String newname/*要修改成的文件名*/) throws IOException {File oldFile = new File(path);if (!oldFile.exists()) {return false;//如果原文件不存在,返回no}File newFile = new File(newname);if (oldFile.renameTo(newFile)) {return true;} else {return false;}}/*** 解压zip压缩文件到指定目录** @param zipPath zip压缩文件绝对路径* @param descDir 指定的解压目录*/public void unzipFile(String zipPath, String descDir) throws IOException {try {File zipFile = new File(zipPath);if (!zipFile.exists()) {throw new IOException("要解压的压缩文件不存在");}File pathFile = new File(descDir);if (!pathFile.exists()) {pathFile.mkdirs();}InputStream input = new FileInputStream(zipPath);unzipWithStream(input, descDir);} catch (Exception e) {throw new IOException(e);}}/*** 解压** @param inputStream* @param descDir*/public void unzipWithStream(InputStream inputStream, String descDir) {if (!descDir.endsWith(File.separator)) {descDir = descDir + File.separator;}try (ZipInputStream zipInputStream = new ZipInputStream(inputStream, Charset.forName("GBK"))) {ZipEntry zipEntry;while ((zipEntry = zipInputStream.getNextEntry()) != null) {String zipEntryNameStr = zipEntry.getName();String outPath = (descDir + zipEntryNameStr).replace("\\", "/");File outFile = new File(outPath.substring(0, outPath.lastIndexOf('/')));if (!outFile.exists()) {outFile.mkdirs();}if (new File(outPath).isDirectory()) {continue;}writeFile(outPath, zipInputStream);zipInputStream.closeEntry();}System.out.println("======解压成功=======");} catch (IOException e) {System.out.println("压缩包处理异常，异常信息{}" + e);}}/*** 将流写到文件中* @param filePath* @param zipInputStream*/public void writeFile(String filePath, ZipInputStream zipInputStream) {try (OutputStream outputStream = new FileOutputStream(filePath)) {byte[] bytes = new byte[4096];int len;while ((len = zipInputStream.read(bytes)) != -1) {outputStream.write(bytes, 0, len);}} catch (IOException ex) {System.out.println("解压文件时，写出到文件出错");}}/*** 压缩成ZIP 方法2 一次性压缩多个文件** @param zipFileName 压缩文件输出* @param srcFiles 需要压缩的文件列表* @throws RuntimeException 压缩失败会抛出运行时异常*/public void toZip(String zipFileName, List<File> srcFiles) {long start = System.currentTimeMillis();ZipOutputStream zos = null;try {FileOutputStream fileOutputStream = new FileOutputStream(zipFileName);zos = new ZipOutputStream(fileOutputStream);for (File srcFile : srcFiles) {compress(srcFile, zos, srcFile.getName(), true);}long end = System.currentTimeMillis();System.out.println("压缩完成，耗时：" + (end - start) + " 毫秒");} catch (Exception e) {throw new RuntimeException("zip error from ZipUtils", e);} finally {if (zos != null) {try {zos.close();} catch (IOException e) {e.printStackTrace();}}}}/*** 递归压缩方法** @param sourceFile 源文件* @param zos zip输出流* @param name 压缩后的名称* @param KeepDirStructure 是否保留原来的目录结构,true:保留目录结构;*false:所有文件跑到压缩包根目录下(注意：不保留目录结构可能会出现同名文件,会压缩失败)* @throws Exception*/public void compress(File sourceFile, ZipOutputStream zos, String name,boolean KeepDirStructure) throws Exception {if (sourceFile.isFile()) {// 向zip输出流中添加一个zip实体，构造器中name为zip实体的文件的名字zos.putNextEntry(new ZipEntry(name));// copy文件到zip输出流中int len;FileInputStream in = new FileInputStream(sourceFile);while ((len = in.read(buf)) != -1) {zos.write(buf, 0, len);}// Complete the entryzos.closeEntry();in.close();} else {File[] listFiles = sourceFile.listFiles();if (listFiles == null || listFiles.length == 0) {// 需要保留原来的文件结构时,需要对空文件夹进行处理if (KeepDirStructure) {// 空文件夹的处理zos.putNextEntry(new ZipEntry(name + "/"));// 没有文件，不需要文件的copyzos.closeEntry();}} else {for (File file : listFiles) {// 判断是否需要保留原来的文件结构if (KeepDirStructure) {// 注意：file.getName()前面需要带上父文件夹的名字加一斜杠,// 不然最后压缩包中就不能保留原来的文件结构,即：所有文件都跑到压缩包根目录下了compress(file, zos, name + "/" + file.getName(), KeepDirStructure);} else {compress(file, zos, file.getName(), KeepDirStructure);}}}}}}
