中国最早做网站是谁,计算机专业就业前景,哪家公司的网站做得好,广州网站优化排名系统一、简介
随着互联网的快速发展#xff0c;大文件的传输成为了互联网应用的重要组成部分。然而#xff0c;由于网络不稳定等因素的影响#xff0c;大文件的传输经常会出现中断的情况#xff0c;这时需要重新传输#xff0c;导致传输效率低下。 为了解决这个问题#xff…
一、简介
随着互联网的快速发展大文件的传输成为了互联网应用的重要组成部分。然而由于网络不稳定等因素的影响大文件的传输经常会出现中断的情况这时需要重新传输导致传输效率低下。 为了解决这个问题可以实现大文件的断点续传功能。断点续传功能可以在传输中断后继续传输而不需要从头开始传输。这样可以大大提高传输的效率。
Spring Boot是一个快速开发的Java Web开发框架可以帮助我们快速搭建一个Web应用程序。在Spring Boot中我们可以很容易地实现大文件的断点续传功能。
本文将介绍如何使用Spring Boot实现大文件的断点续传功能。
二、Spring Boot实现大文件断点续传的原理
实现大文件的断点续传功能需要在客户端和服务端都进行相应的实现。 实现示例1
服务端如何将一个大视频文件做切分分段响应给客户端让浏览器可以渐进式地播放。
Spring Boot实现HTTP分片下载断点续传从而实现H5页面的大视频播放问题实现渐进式播放每次只播放需要播放的内容就可以了不需要加载整个文件到内存中。
文件的断点续传、文件多线程并发下载迅雷就是这么玩的等。 dependencyManagementdependenciesdependencygroupIdcn.hutool/groupIdartifactIdhutool-bom/artifactIdversion5.8.18/versiontypepom/typescopeimport/scope/dependency/dependencies/dependencyManagementdependenciesdependencygroupIdcn.hutool/groupIdartifactIdhutool-core/artifactId/dependencydependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdoptionaltrue/optional/dependency/dependencies代码实现
ResourceController
package com.example.insurance.controller;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;import com.example.insurance.common.ContentRange;
import com.example.insurance.common.MediaContentUtil;
import com.example.insurance.common.NioUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRange;
import org.springframework.http.HttpStatus;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StopWatch;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** 内容资源控制器*/
SuppressWarnings(unused)
Slf4j
RestController(resourceController)
RequestMapping(path /resource)
public class ResourceController {/*** 获取文件内容** param fileName 内容文件名称* param response 响应对象*/GetMapping(/media/{fileName})public void getMedia(PathVariable String fileName, HttpServletRequest request, HttpServletResponse response,RequestHeader HttpHeaders headers) {
// printRequestInfo(fileName, request, headers);String filePath MediaContentUtil.filePath();try {this.download(fileName, filePath, request, response, headers);} catch (Exception e) {log.error(getMedia error, fileName{}, fileName, e);}}/*** 获取封面内容** param fileName 内容封面名称* param response 响应对象*/GetMapping(/cover/{fileName})public void getCover(PathVariable String fileName, HttpServletRequest request, HttpServletResponse response,RequestHeader HttpHeaders headers) {
// printRequestInfo(fileName, request, headers);String filePath MediaContentUtil.filePath();try {this.download(fileName, filePath, request, response, headers);} catch (Exception e) {log.error(getCover error, fileName{}, fileName, e);}}// internal private static void printRequestInfo(String fileName, HttpServletRequest request, HttpHeaders headers) {String requestUri request.getRequestURI();String queryString request.getQueryString();log.debug(file{}, url{}?{}, fileName, requestUri, queryString);log.info(headers{}, headers);}/*** 设置请求响应状态、头信息、内容类型与长度 等。* pre* a hrefhttps://www.rfc-editor.org/rfc/rfc7233* HTTP/1.1 Range Requests/a* 2. Range Units* 4. Responses to a Range Request** a hrefhttps://www.rfc-editor.org/rfc/rfc2616.html* HTTP/1.1/a* 10.2.7 206 Partial Content* 14.5 Accept-Ranges* 14.13 Content-Length* 14.16 Content-Range* 14.17 Content-Type* 19.5.1 Content-Disposition* 15.5 Content-Disposition Issues** a hrefhttps://www.rfc-editor.org/rfc/rfc2183* Content-Disposition/a* 2. The Content-Disposition Header Field* 2.1 The Inline Disposition Type* 2.3 The Filename Parameter* /pre** param response 请求响应对象* param fileName 请求的文件名称* param contentType 内容类型* param contentRange 内容范围对象*/private static void setResponse(HttpServletResponse response, String fileName, String contentType,ContentRange contentRange) {// http状态码要为206表示获取部分内容response.setStatus(HttpStatus.PARTIAL_CONTENT.value());// 支持断点续传获取部分字节内容// Accept-Rangesbytes表示支持Range请求response.setHeader(HttpHeaders.ACCEPT_RANGES, ContentRange.BYTES_STRING);// inline表示浏览器直接使用attachment表示下载fileName表示下载的文件名response.setHeader(HttpHeaders.CONTENT_DISPOSITION,inline;filename MediaContentUtil.encode(fileName));// Content-Range格式为[要下载的开始位置]-[结束位置]/[文件总大小]// Content-Range: bytes 0-10/3103格式为bytes 开始-结束/全部response.setHeader(HttpHeaders.CONTENT_RANGE, contentRange.toContentRange());response.setContentType(contentType);// Content-Length: 11本次内容的大小response.setContentLengthLong(contentRange.applyAsContentLength());}/*** a hrefhttps://www.jianshu.com/p/08db5ba3bc95* Spring Boot 处理 HTTP Headers/a*/private void download(String fileName, String path, HttpServletRequest request, HttpServletResponse response,HttpHeaders headers)throws IOException {Path filePath Paths.get(path fileName);if (!Files.exists(filePath)) {log.warn(file not exist, filePath{}, filePath);return;}long fileLength Files.size(filePath);
// long fileLength2 filePath.toFile().length() - 1;
// // fileLength1184856, fileLength21184855
// log.info(fileLength{}, fileLength2{}, fileLength, fileLength2);// 内容范围ContentRange contentRange applyAsContentRange(headers, fileLength, request);// 要下载的长度long contentLength contentRange.applyAsContentLength();log.debug(contentRange{}, contentLength{}, contentRange, contentLength);// 文件类型String contentType request.getServletContext().getMimeType(fileName);// mimeTypevideo/mp4, CONTENT_TYPEnulllog.debug(mimeType{}, CONTENT_TYPE{}, contentType, request.getContentType());setResponse(response, fileName, contentType, contentRange);// 耗时指标统计StopWatch stopWatch new StopWatch(downloadFile);stopWatch.start(fileName);try {// case-1.参考网上他人的实现
// if (fileLength Integer.MAX_VALUE) {
// NioUtils.copy(filePath, response, contentRange);
// } else {
// NioUtils.copyByChannelAndBuffer(filePath, response, contentRange);
// }// case-2.使用现成APINioUtils.copyByBio(filePath, response, contentRange);
// NioUtils.copyByNio(filePath, response, contentRange);// case-3.视频分段渐进式播放
// if (contentType.startsWith(video)) {
// NioUtils.copyForBufferSize(filePath, response, contentRange);
// } else {
// // 图片、PDF等文件
// NioUtils.copyByBio(filePath, response, contentRange);
// }} finally {stopWatch.stop();log.info(download file, fileName{}, time{} ms, fileName, stopWatch.getTotalTimeMillis());}}private static ContentRange applyAsContentRange(HttpHeaders headers, long fileLength, HttpServletRequest request) {/** 3.1. Range - HTTP/1.1 Range Requests* https://www.rfc-editor.org/rfc/rfc7233#section-3.1* Range: bytes first-byte-pos - [ last-byte-pos ]** For example:* bytes0-* bytes0-499*/// Range告知服务端客户端下载该文件想要从指定的位置开始下载ListHttpRange httpRanges headers.getRange();String range request.getHeader(HttpHeaders.RANGE);// httpRanges[], rangenull// httpRanges[448135688-], rangebytes448135688-log.debug(httpRanges{}, range{}, httpRanges, range);// 开始下载位置long firstBytePos;// 结束下载位置long lastBytePos;if (CollectionUtils.isEmpty(httpRanges)) {firstBytePos 0;lastBytePos fileLength - 1;} else {HttpRange httpRange httpRanges.get(0);firstBytePos httpRange.getRangeStart(fileLength);lastBytePos httpRange.getRangeEnd(fileLength);}return new ContentRange(firstBytePos, lastBytePos, fileLength);}
}
NioUtils
package com.example.insurance.common;import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;import cn.hutool.core.io.IORuntimeException;
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.io.NioUtil;
import cn.hutool.core.io.StreamProgress;
import cn.hutool.core.io.unit.DataSize;
import lombok.extern.slf4j.Slf4j;
import org.apache.catalina.connector.ClientAbortException;/*** NIO相关工具封装主要针对Channel读写、拷贝等封装*/
Slf4j
public final class NioUtils {/*** 缓冲区大小 16KB** see NioUtil#DEFAULT_BUFFER_SIZE* see NioUtil#DEFAULT_LARGE_BUFFER_SIZE*/
// private static final int BUFFER_SIZE NioUtil.DEFAULT_MIDDLE_BUFFER_SIZE;private static final int BUFFER_SIZE (int) DataSize.ofKilobytes(16L).toBytes();/*** pre* a hrefhttps://blog.csdn.net/qq_32099833/article/details/109703883* Java后端实现视频分段渐进式播放/a* 服务端如何将一个大的视频文件做切分分段响应给客户端让浏览器可以渐进式地播放。* 文件的断点续传、文件多线程并发下载迅雷就是这么玩的等。** a hrefhttps://blog.csdn.net/qq_32099833/article/details/109630499* 大文件分片上传前后端实现/a* /pre*/public static void copyForBufferSize(Path filePath, HttpServletResponse response, ContentRange contentRange) {String fileName filePath.getFileName().toString();RandomAccessFile randomAccessFile null;OutputStream outputStream null;try {// 随机读文件randomAccessFile new RandomAccessFile(filePath.toFile(), r);// 移动访问指针到指定位置randomAccessFile.seek(contentRange.getStart());// 注意缓冲区大小 2MB视频加载正常1MB时有部分视频加载失败int bufferSize BUFFER_SIZE;//获取响应的输出流outputStream new BufferedOutputStream(response.getOutputStream(), bufferSize);// 每次请求只返回1MB的视频流byte[] buffer new byte[bufferSize];int len randomAccessFile.read(buffer);//设置此次相应返回的数据长度response.setContentLength(len);// 将这1MB的视频流响应给客户端outputStream.write(buffer, 0, len);log.info(file download complete, fileName{}, contentRange{},fileName, contentRange.toContentRange());} catch (ClientAbortException | IORuntimeException e) {// 捕获此异常表示用户停止下载log.warn(client stop file download, fileName{}, fileName);} catch (Exception e) {log.error(file download error, fileName{}, fileName, e);} finally {IoUtil.close(outputStream);IoUtil.close(randomAccessFile);}}/*** 拷贝流拷贝后关闭流。** param filePath 源文件路径* param response 请求响应* param contentRange 内容范围*/public static void copyByBio(Path filePath, HttpServletResponse response, ContentRange contentRange) {String fileName filePath.getFileName().toString();InputStream inputStream null;OutputStream outputStream null;try {RandomAccessFile randomAccessFile new RandomAccessFile(filePath.toFile(), r);randomAccessFile.seek(contentRange.getStart());inputStream Channels.newInputStream(randomAccessFile.getChannel());outputStream new BufferedOutputStream(response.getOutputStream(), BUFFER_SIZE);StreamProgress streamProgress new StreamProgressImpl(fileName);long transmitted IoUtil.copy(inputStream, outputStream, BUFFER_SIZE, streamProgress);log.info(file download complete, fileName{}, transmitted{}, fileName, transmitted);} catch (ClientAbortException | IORuntimeException e) {// 捕获此异常表示用户停止下载log.warn(client stop file download, fileName{}, fileName);} catch (Exception e) {log.error(file download error, fileName{}, fileName, e);} finally {IoUtil.close(outputStream);IoUtil.close(inputStream);}}/*** 拷贝流拷贝后关闭流。* pre* a hrefhttps://www.cnblogs.com/czwbig/p/10035631.html* Java NIO 学习笔记一----概述Channel/Buffer/a* /pre** param filePath 源文件路径* param response 请求响应* param contentRange 内容范围*/public static void copyByNio(Path filePath, HttpServletResponse response, ContentRange contentRange) {String fileName filePath.getFileName().toString();InputStream inputStream null;OutputStream outputStream null;try {RandomAccessFile randomAccessFile new RandomAccessFile(filePath.toFile(), r);randomAccessFile.seek(contentRange.getStart());inputStream Channels.newInputStream(randomAccessFile.getChannel());outputStream new BufferedOutputStream(response.getOutputStream(), BUFFER_SIZE);StreamProgress streamProgress new StreamProgressImpl(fileName);long transmitted NioUtil.copyByNIO(inputStream, outputStream,BUFFER_SIZE, streamProgress);log.info(file download complete, fileName{}, transmitted{}, fileName, transmitted);} catch (ClientAbortException | IORuntimeException e) {// 捕获此异常表示用户停止下载log.warn(client stop file download, fileName{}, fileName);} catch (Exception e) {log.error(file download error, fileName{}, fileName, e);} finally {IoUtil.close(outputStream);IoUtil.close(inputStream);}}/*** pre* a hrefhttps://blog.csdn.net/lovequanquqn/article/details/104562945* SpringBoot Java实现Http方式分片下载断点续传实现H5大视频渐进式播放/a* SpringBoot 实现Http分片下载断点续传从而实现H5页面的大视频播放问题实现渐进式播放每次只播放需要播放的内容就可以了不需要加载整个文件到内存中。* 二、Http分片下载断点续传实现* 四、缓存文件定时删除任务* /pre*/public static void copy(Path filePath, HttpServletResponse response, ContentRange contentRange) {String fileName filePath.getFileName().toString();// 要下载的长度long contentLength contentRange.applyAsContentLength();BufferedOutputStream outputStream null;RandomAccessFile randomAccessFile null;// 已传送数据大小long transmitted 0;try {randomAccessFile new RandomAccessFile(filePath.toFile(), r);randomAccessFile.seek(contentRange.getStart());outputStream new BufferedOutputStream(response.getOutputStream(), BUFFER_SIZE);// 把数据读取到缓冲区中byte[] buffer new byte[BUFFER_SIZE];int len BUFFER_SIZE;//warning判断是否到了最后不足4096buffer的length个byte这个逻辑(transmitted len) contentLength要放前面//不然会会先读取randomAccessFile造成后面读取位置出错;while ((transmitted len) contentLength (len randomAccessFile.read(buffer)) ! -1) {outputStream.write(buffer, 0, len);transmitted len;log.info(fileName{}, transmitted{}, fileName, transmitted);}//处理不足buffer.length部分if (transmitted contentLength) {len randomAccessFile.read(buffer, 0, (int) (contentLength - transmitted));outputStream.write(buffer, 0, len);transmitted len;log.info(fileName{}, transmitted{}, fileName, transmitted);}log.info(file download complete, fileName{}, transmitted{}, fileName, transmitted);} catch (ClientAbortException e) {// 捕获此异常表示用户停止下载log.warn(client stop file download, fileName{}, transmitted{}, fileName, transmitted);} catch (Exception e) {log.error(file download error, fileName{}, transmitted{}, fileName, transmitted, e);} finally {IoUtil.close(outputStream);IoUtil.close(randomAccessFile);}}/*** 通过数据传输通道和缓冲区读取文件数据。* pre* 当文件长度超过{link Integer#MAX_VALUE}时* 使用{link FileChannel#map(FileChannel.MapMode, long, long)}报如下异常。* java.lang.IllegalArgumentException: Size exceeds Integer.MAX_VALUE* at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:863)* at com.example.insurance.controller.ResourceController.download(ResourceController.java:200)* /pre** param filePath 源文件路径* param response 请求响应* param contentRange 内容范围*/public static void copyByChannelAndBuffer(Path filePath, HttpServletResponse response, ContentRange contentRange) {String fileName filePath.getFileName().toString();// 要下载的长度long contentLength contentRange.applyAsContentLength();BufferedOutputStream outputStream null;FileChannel inChannel null;// 已传送数据大小long transmitted 0;long firstBytePos contentRange.getStart();long fileLength contentRange.getLength();try {inChannel FileChannel.open(filePath, StandardOpenOption.READ, StandardOpenOption.WRITE);// 建立直接缓冲区MappedByteBuffer inMap inChannel.map(FileChannel.MapMode.READ_ONLY, firstBytePos, fileLength);outputStream new BufferedOutputStream(response.getOutputStream(), BUFFER_SIZE);// 把数据读取到缓冲区中byte[] buffer new byte[BUFFER_SIZE];int len BUFFER_SIZE;// warning判断是否到了最后不足4096buffer的length个byte这个逻辑(transmitted len) contentLength要放前面// 不然会会先读取file造成后面读取位置出错while ((transmitted len) contentLength) {inMap.get(buffer);outputStream.write(buffer, 0, len);transmitted len;log.info(fileName{}, transmitted{}, fileName, transmitted);}// 处理不足buffer.length部分if (transmitted contentLength) {len (int) (contentLength - transmitted);buffer new byte[len];inMap.get(buffer);outputStream.write(buffer, 0, len);transmitted len;log.info(fileName{}, transmitted{}, fileName, transmitted);}log.info(file download complete, fileName{}, transmitted{}, fileName, transmitted);} catch (ClientAbortException e) {// 捕获此异常表示用户停止下载log.warn(client stop file download, fileName{}, transmitted{}, fileName, transmitted);} catch (Exception e) {log.error(file download error, fileName{}, transmitted{}, fileName, transmitted, e);} finally {IoUtil.close(outputStream);IoUtil.close(inChannel);}}}
ContentRange package com.example.insurance.common;import lombok.AllArgsConstructor;
import lombok.Getter;/*** 内容范围对象* pre* a hrefhttps://www.rfc-editor.org/rfc/rfc7233#section-4.2* 4.2. Content-Range - HTTP/1.1 Range Requests/a* Content-Range: bytes first-byte-pos - last-byte-pos / complete-length** For example:* Content-Range: bytes 0-499/1234* /pre** see org.apache.catalina.servlets.DefaultServlet.Range*/
Getter
AllArgsConstructor
public class ContentRange {/*** 第一个字节的位置*/private final long start;/*** 最后一个字节的位置*/private long end;/*** 内容完整的长度/总长度*/private final long length;public static final String BYTES_STRING bytes;/*** 组装内容范围的响应头。* pre* a hrefhttps://www.rfc-editor.org/rfc/rfc7233#section-4.2* 4.2. Content-Range - HTTP/1.1 Range Requests/a* Content-Range: bytes first-byte-pos - last-byte-pos / complete-length** For example:* Content-Range: bytes 0-499/1234* /pre** return 内容范围的响应头*/public String toContentRange() {return BYTES_STRING start - end / length;
// return bytes start - end / length;}/*** 计算内容完整的长度/总长度。** return 内容完整的长度/总长度*/public long applyAsContentLength() {return end - start 1;}/*** Validate range.** return true if the range is valid, otherwise false*/public boolean validate() {if (end length) {end length - 1;}return (start 0) (end 0) (start end) (length 0);}Overridepublic String toString() {return firstBytePos start , lastBytePos end , fileLength length;}
}
StreamProgressImpl package com.example.insurance.common;import cn.hutool.core.io.StreamProgress;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;/*** 数据流进度条*/
Slf4j
AllArgsConstructor
public class StreamProgressImpl implements StreamProgress {private final String fileName;Overridepublic void start() {log.info(start progress {}, fileName);}Overridepublic void progress(long total, long progressSize) {log.debug(progress {}, total{}, progressSize{}, fileName, total, progressSize);}Overridepublic void finish() {log.info(finish progress {}, fileName);}
}
MediaContentUtil package com.example.insurance.common;import java.net.URLDecoder;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;/*** 文件内容辅助方法集*/
public final class MediaContentUtil {public static String filePath() {String osName System.getProperty(os.name);String filePath /data/files/;if (osName.startsWith(Windows)) {filePath D:\ filePath;}
// else if (osName.startsWith(Linux)) {
// filePath MediaContentConstant.FILE_PATH;
// }else if (osName.startsWith(Mac) || osName.startsWith(Linux)) {filePath /home/admin filePath;}return filePath;}public static String encode(String fileName) {return URLEncoder.encode(fileName, StandardCharsets.UTF_8);}public static String decode(String fileName) {return URLDecoder.decode(fileName, StandardCharsets.UTF_8);}
}实现示例2
代码实现
1客户端需要实现以下功能
建立连接客户端需要连接服务端并建立连接。分块传输文件客户端需要将文件分成若干块并逐块传输。在传输中每个块传输完成后需要将已传输的位置发送给服务端以便服务端记录传输位置。计算MD5值在传输完成后客户端需要计算文件的MD5值以确保传输的完整性。与服务端比较MD5值在计算出MD5值后客户端需要将MD5值发送给服务端并与服务端返回的MD5值比较以确保传输的完整性。
2服务端需要实现以下功能
建立连接服务端需要等待客户端连接并建立连接。接收文件服务端需要接收客户端传输的文件。在接收文件时需要记录传输的位置并在传输中断后继续接收文件。计算MD5值在接收完成后服务端需要计算文件的MD5值以确保传输的完整性。返回MD5值在计算出MD5值后服务端需要将MD5值返回给客户端。
1.编写客户端代码
在客户端中我们需要实现以下功能
建立连接使用Java的Socket类建立与服务端的连接。分块传输文件将文件分成若干块并逐块传输。在传输中每个块传输完成后需要将已传输的位置发送给服务端以便服务端记录传输位置。计算MD5值在传输完成后计算文件的MD5值以确保传输的完整性。与服务端比较MD5值将MD5值发送给服务端并与服务端返回的MD5值比较以确保传输的完整性。
以下是客户端代码的实现
RestController
RequestMapping(/file)
public class FileController {PostMapping(/upload)public ResponseEntity? uploadFile(RequestParam(file) MultipartFile file,RequestParam(fileName) String fileName,RequestParam(startPosition) long startPosition) {try { // 建立连接Socket socket new Socket(localhost, 8080);OutputStream outputStream socket.getOutputStream();ObjectOutputStream objectOutputStream new ObjectOutputStream(outputStream);// 分块传输文件FileInputStream fileInputStream (FileInputStream) file.getInputStream();fileInputStream.skip(startPosition);byte[] buffer new byte[1024];int len;while ((len fileInputStream.read(buffer)) ! -1) {outputStream.write(buffer, 0, len);}// 计算MD5值fileInputStream.getChannel().position(0);String md5 DigestUtils.md5Hex(fileInputStream);// 与服务端比较MD5值InputStream inputStream socket.getInputStream();ObjectInputStream objectInputStream new ObjectInputStream(inputStream);String serverMd5 (String) objectInputStream.readObject();if (!md5.equals(serverMd5)) {throw new RuntimeException(MD5值不匹配);}// 关闭连接objectOutputStream.close();outputStream.close();socket.close();} catch (Exception e) {e.printStackTrace();return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(e.getMessage());}return ResponseEntity.ok().build();}
}
2.编写服务端代码
在服务端中我们需要实现以下功能
建立连接使用Java的ServerSocket类等待客户端连接并建立连接。接收文件接收客户端传输的文件。在接收文件时需要记录传输的位置并在传输中断后继续接收文件。计算MD5值在接收完成后计算文件的MD5值以确保传输的完整性。返回MD5值将MD5值返回给客户端。
以下是服务端代码的实现
RestController
RequestMapping(/file)
public class FileController {private final String FILE_PATH /tmp/upload/;PostMapping(/upload)public ResponseEntity? uploadFile(HttpServletRequest request, RequestParam(fileName) String fileName) {try {// 建立连接 ServerSocket serverSocket new ServerSocket(8080);Socket socket serverSocket.accept();InputStream inputStream socket.getInputStream();ObjectInputStream objectInputStream new ObjectInputStream(inputStream);// 接收文件 String filePath FILE_PATH fileName;RandomAccessFile randomAccessFile new RandomAccessFile(filePath, rw);long startPosition randomAccessFile.length();randomAccessFile.seek(startPosition);byte[] buffer new byte[1024];int len;while ((len inputStream.read(buffer)) ! -1) {randomAccessFile.write(buffer, 0, len);} // 计算MD5值 FileInputStream fileInputStream new FileInputStream(filePath);String md5 DigestUtils.md5Hex(fileInputStream);// 返回MD5值 OutputStream outputStream socket.getOutputStream();ObjectOutputStream objectOutputStream new ObjectOutputStream(outputStream);objectOutputStream.writeObject(md5); // 关闭连objectInputStream.close();inputStream.close();randomAccessFile.close();socket.close();serverSocket.close();} catch (Exception e) {e.printStackTrace();return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(e.getMessage());}return ResponseEntity.ok().build();}
}
3. 编写前端代码
在前端中我们需要实现以下功能
选择文件提供一个文件选择框让用户选择要上传的文件。分块上传将文件分块上传到服务器。在上传过程中需要记录上传的位置并在上传中断后继续上传。
以下是前端代码的实现
html
headmeta charsetUTF-8titleSpring Boot File Upload/titlescript srchttps://cdn.bootcss.com/jquery/3.3.1/jquery.min.js/script
/head
bodyinput typefile idfile
button onclickupload()Upload/button
script var file;
var startPosition 0;
$(#file).on(change, function () {file this.files[0];
});function upload() {if (!file) {alert(Please select a file!);return;}var formData new FormData();formData.append(file, file);formData.append(fileName, file.name);formData.append(startPosition, startPosition);$.ajax({url: /file/upload,type: post,data: formData,cache: false,processData: false,contentType: false,success: function () {alert(Upload completed!);},error: function (xhr) {alert(xhr.responseText);},xhr: function () {var xhr $.ajaxSettings.xhr();xhr.upload.onprogress function (e) {if (e.lengthComputable) {var percent e.loaded / e.total * 100;console.log(Upload percent: percent.toFixed(2) %);}};return xhr;}});
}/script
/body
/html
总结
本文介绍了如何使用Spring Boot实现大文件断点续传。在实现中我们使用了Java的RandomAccessFile类来实现文件的分块上传和断点续传使用了Spring Boot的RestController注解来实现Web服务的开发使用了jQuery的Ajax函数来实现前端页面的开发。
在实际开发中需要注意以下几点
上传文件的大小和分块的大小需要根据实际情况进行设置以确保上传速度和服务器的稳定性。在上传过程中需要对异常情况进行处理以确保程序的健壮性。在上传完成后需要对上传的文件进行校验以确保传输的完整性。
