1.分块上传使用场景2.实现原理

实现原理其实很简单，核心就是客户端把大文件按照一定规则进行拆分，比如20MB为一个小块，分解成一个一个的文件块，然后把这些文件块单独上传到服务端，等到所有的文件块都上传完毕之后，客户端再通知服务端进行文件合并的操作，合并完成之后整个任务结束。

3.代码工程实验目的

实现大文件分块上传

pom.xml

"1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot-demoartifactId>
        <groupId>com.etgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>
    <artifactId>fileartifactId>
    <properties>
        <maven.compiler.source>8maven.compiler.source>
        <maven.compiler.target>8maven.compiler.target>
    properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-autoconfigureartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
        <dependency>
            <groupId>org.apache.httpcomponentsgroupId>
            <artifactId>httpclientartifactId>
        dependency>
        <dependency>
            <groupId>org.apache.httpcomponentsgroupId>
            <artifactId>httpmimeartifactId>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
        dependency>
        <dependency>
            <groupId>cn.hutoolgroupId>
            <artifactId>hutool-coreartifactId>
            <version>5.8.15version>
        dependency>
    dependencies>
project>

controller

package com.et.controller;
import com.et.bean.Chunk;
import com.et.bean.FileInfo;
import com.et.service.ChunkService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
@RequestMapping("file")
public class ChunkController {
    @Autowired
    private ChunkService chunkService;
    /**
     * upload by part
     *
     * @param chunk
     * @return
     */
    @PostMapping(value = "chunk")
    public ResponseEntity chunk(Chunk chunk) {
        chunkService.chunk(chunk);
        return ResponseEntity.ok("File Chunk Upload Success");
    }
    /**
     * merge
     *
     * @param filename
     * @return
     */
    @GetMapping(value = "merge")
    public ResponseEntity<Void> merge(@RequestParam("filename") String filename) {
        chunkService.merge(filename);
        return ResponseEntity.ok().build();
    }
    /**
     * get fileName
     *
     * @return files
     */
    @GetMapping("/files")
    public ResponseEntity> list() {
        return ResponseEntity.ok(chunkService.list());
    }
    /**
     * get single file
     *
     * @param filename
     * @return file
     */
    @GetMapping("/files/{filename:.+}")
    public ResponseEntity getFile(@PathVariable("filename") String filename) {
        return ResponseEntity.ok().header(HttpHeaders.CONTENT_DISPOSITION,
                "attachment; filename=\"" + filename + "\"").body(chunkService.getFile(filename));
    }
}

config

package com.et.config;
import com.et.service.FileClient;
import com.et.service.impl.LocalFileSystemClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Supplier;
@Configuration
public class FileClientConfig {
    @Value("${file.client.type:local-file}")
    private String fileClientType;
    private static final Map> FILE_CLIENT_SUPPLY = new HashMap>() {
        {
            put("local-file", LocalFileSystemClient::new);
           // put("aws-s3", AWSFileClient::new);
        }
    };
    /**
     * get client
     *
     * @return 
     */
    @Bean
    public FileClient fileClient() {
        return FILE_CLIENT_SUPPLY.get(fileClientType).get();
    }
}

service

package com.et.service;
import com.et.bean.Chunk;
import com.et.bean.FileInfo;
import org.springframework.core.io.Resource;
import java.util.List;
public interface ChunkService {
    void chunk(Chunk chunk);
    void merge(String filename);
    List list();
    Resource getFile(String filename);
}
package com.et.service.impl;
import com.et.bean.Chunk;
import com.et.bean.ChunkProcess;
import com.et.bean.FileInfo;
import com.et.service.ChunkService;
import com.et.service.FileClient;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Service;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicBoolean;
@Service
@Slf4j
public class ChunkServiceImpl implements ChunkService {
    // process
    private static final Map CHUNK_PROCESS_STORAGE = new ConcurrentHashMap<>();
    // file list
    private static final List FILE_STORAGE = new CopyOnWriteArrayList<>();
    @Autowired
    private FileClient fileClient;
    @Override
    public void chunk(Chunk chunk) {
        String filename = chunk.getFilename();
        boolean match = FILE_STORAGE.stream().anyMatch(fileInfo -> fileInfo.getFileName().equals(filename));
        if (match) {
            throw new RuntimeException("File [ " + filename + " ] already exist");
        }
        ChunkProcess chunkProcess;
        String uploadId;
        if (CHUNK_PROCESS_STORAGE.containsKey(filename)) {
            chunkProcess = CHUNK_PROCESS_STORAGE.get(filename);
            uploadId = chunkProcess.getUploadId();
            AtomicBoolean isUploaded = new AtomicBoolean(false);
            Optional.ofNullable(chunkProcess.getChunkList()).ifPresent(chunkPartList ->
                    isUploaded.set(chunkPartList.stream().anyMatch(chunkPart -> chunkPart.getChunkNumber() == chunk.getChunkNumber())));
            if (isUploaded.get()) {
                log.info("file【{}】chunk【{}】upload，jump", chunk.getFilename(), chunk.getChunkNumber());
                return;
            }
        } else {
            uploadId = fileClient.initTask(filename);
            chunkProcess = new ChunkProcess().setFilename(filename).setUploadId(uploadId);
            CHUNK_PROCESS_STORAGE.put(filename, chunkProcess);
        }
        List chunkList = chunkProcess.getChunkList();
        String chunkId = fileClient.chunk(chunk, uploadId);
        chunkList.add(new ChunkProcess.ChunkPart(chunkId, chunk.getChunkNumber()));
        CHUNK_PROCESS_STORAGE.put(filename, chunkProcess.setChunkList(chunkList));
    }
    @Override
    public void merge(String filename) {
        ChunkProcess chunkProcess = CHUNK_PROCESS_STORAGE.get(filename);
        fileClient.merge(chunkProcess);
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String currentTime = simpleDateFormat.format(new Date());
        FILE_STORAGE.add(new FileInfo().setUploadTime(currentTime).setFileName(filename));
        CHUNK_PROCESS_STORAGE.remove(filename);
    }
    @Override
    public List list() {
        return FILE_STORAGE;
    }
    @Override
    public Resource getFile(String filename) {
        return fileClient.getFile(filename);
    }
}
package com.et.service.impl;
import com.et.bean.FileInfo;
import com.et.service.FileUploadService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Service;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
@Service
@Slf4j
public class FileUploadServiceImpl implements FileUploadService {
    @Value("${upload.path:/data/upload/}")
    private String filePath;
    private static final List FILE_STORAGE = new CopyOnWriteArrayList<>();
    @Override
    public void upload(MultipartFile[] files) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        for (MultipartFile file : files) {
            String fileName = file.getOriginalFilename();
            boolean match = FILE_STORAGE.stream().anyMatch(fileInfo -> fileInfo.getFileName().equals(fileName));
            if (match) {
                throw new RuntimeException("File [ " + fileName + " ] already exist");
            }
            String currentTime = simpleDateFormat.format(new Date());
            try (InputStream in = file.getInputStream();
                 OutputStream out = Files.newOutputStream(Paths.get(filePath + fileName))) {
                FileCopyUtils.copy(in, out);
            } catch (IOException e) {
                log.error("File [{}] upload failed", fileName, e);
                throw new RuntimeException(e);
            }
            FileInfo fileInfo = new FileInfo().setFileName(fileName).setUploadTime(currentTime);
            FILE_STORAGE.add(fileInfo);
        }
    }
    @Override
    public List list() {
        return FILE_STORAGE;
    }
    @Override
    public Resource getFile(String fileName) {
        FILE_STORAGE.stream()
                .filter(info -> info.getFileName().equals(fileName))
                .findFirst()
                .orElseThrow(() -> new RuntimeException("File [ " + fileName + " ] not exist"));
        File file = new File(filePath + fileName);
        return new FileSystemResource(file);
    }
}

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库4.测试

5.引用