java分片上传/合并

本文介绍了文件分片上传与合并的实现代码。Controller层通过Rchunk方法接收分片数据并调用Service层处理Service层使用ChunkUtils.createChunk保存分片文件。分片信息通过ChunkUploadDTO实体类传输包含文件MD5、分片索引等字段。合并时先验证分片完整性再通过mergeChunks方法将所有分片按顺序合并为完整文件合并完成后删除临时分块。代码采用try-with-resources确保流关闭并通过日志记录异常情况。Controller层分片代码public R chunk(ChunkUploadDTO dto) throws IOException { chunkService.chunk(dto); return new R(0,Upload success!); }Service层分片代码public void chunk(ChunkUploadDTO dto) { try { dto.setUploadRootDir(分片保存路径); ChunkUtils.createChunk(dto); } catch (Exception e) { e.printStackTrace(); } }ChunkUploadDTO分片/合并实体类代码Data public class ChunkUploadDTO { /** 文件唯一标识MD5 */ private String fileMd5; /** 分片索引从0开始 */ private Integer chunkIndex; /** 总分片数 */ private Integer chunkCount; /** 原文件名 */ private String fileName; /** 分片文件 */ private MultipartFile chunkFile; private Integer totalChunks; // 总分片数 private String uploadRootDir; }Controller层合并代码PostMapping(接口名) LogApi(logType LogType.IN, logOperation 合并大文件, isLogParams false, isLogDetail false) public R merge(ChunkUploadDTO dto) { return mergeService.merge(dto); }Service层合并代码public R merge(ChunkUploadDTO dto) { try { String RootDir ChunkUtils.merge(合并路径, dto.getFileMd5(), dto.getTotalChunks(), dto.getFileName()); return new R(RootDir ); } catch (Exception e) { e.printStackTrace(); log.error(扫描入库异常[{}], e.getMessage()); return new R(486); } }ChunkUtil类public static String merge(String uploadRootDir,String fileMd5,Integer totalChunks,String fileName) throws Exception { // 验证所有分块是否完整 if (!validateChunks(uploadRootDir, fileMd5, totalChunks)) { log.info(Chunk incomplete); } // 合并分块 mergeChunks(uploadRootDir File.separatorChar, fileMd5 File.separatorChar, fileName, totalChunks); String scanningRootDir uploadRootDir File.separatorChar fileMd5 File.separatorChar fileName; return scanningRootDir; } private static void mergeChunks(String chunkDir, String fileDir, String fileName, int totalChunks) throws IOException { String address chunkDir fileDir fileName; File outputFile new File(address); try (FileOutputStream fos new FileOutputStream(outputFile, false)) { for (int i 0; i totalChunks; i) { File chunkFile new File(chunkDir fileDir i); Files.copy(chunkFile.toPath(), fos); chunkFile.delete(); // 删除临时分块 } } }