java实现分布式分片文件上传下载 代码

以下是Java实现分布式分片文件上传下载的示例代码，使用了Spring Boot和FastDFS客户端：

上传文件：

import java.io.IOException;
import java.io.InputStream;

import org.csource.common.MyException;
import org.csource.fastdfs.ClientGlobal;
import org.csource.fastdfs.StorageClient1;
import org.csource.fastdfs.StorageServer;
import org.csource.fastdfs.TrackerServer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

@Service
public class FileService {
    
    @Autowired
    private FastDFSClient fastDFSClient;
    
    public String uploadFile(MultipartFile file) throws IOException, MyException {
        String filename = file.getOriginalFilename();
        InputStream inputStream = file.getInputStream();
        String fileId = fastDFSClient.uploadFile(inputStream, filename);
        return fileId;
    }
    
    public void deleteFile(String fileId) throws IOException, MyException {
        fastDFSClient.deleteFile(fileId);
    }
    
}

@Service
public class FastDFSClient {
    
    public static final String DEFAULT_GROUP = "group1";
    
    private StorageClient1 storageClient;
    
    public FastDFSClient() throws IOException, MyException {
        ClientGlobal.init("fdfs_client.conf");
        TrackerServer trackerServer = getTrackerServer();
        StorageServer storageServer = null;
        storageClient = new StorageClient1(trackerServer, storageServer);
    }
    
    public String uploadFile(InputStream inputStream, String filename) throws IOException, MyException {
        byte[] fileBytes = IOUtils.toByteArray(inputStream);
        String[] result = storageClient.upload_file(fileBytes, FilenameUtils.getExtension(filename), null);
        return getFullPath(result[0], result[1]);
    }
    
    public void deleteFile(String fileId) throws IOException, MyException {
        String[] result = splitFileId(fileId);
        storageClient.delete_file(result[0], result[1]);
    }
    
    private TrackerServer getTrackerServer() throws IOException {
        TrackerClient trackerClient = new TrackerClient();
        return trackerClient.getConnection();
    }
    
    private String[] splitFileId(String fileId) {
        return fileId.split("/", 2);
    }
    
    private String getFullPath(String group, String path) {
        return String.format("%s/%s", group, path);
    }
    
}

下载文件：

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.csource.common.MyException;
import org.csource.fastdfs.ClientGlobal;
import org.csource.fastdfs.DownloadCallback;
import org.csource.fastdfs.DownloadFileWriter;
import org.csource.fastdfs.StorageClient1;
import org.csource.fastdfs.StorageServer;
import org.csource.fastdfs.TrackerServer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.StreamUtils;

@Service
public class FileService {

    @Autowired
    private FastDFSClient fastDFSClient;
    
    public InputStream downloadFile(String fileId) throws IOException, MyException {
        byte[] fileBytes = fastDFSClient.downloadFile(fileId);
        return new ByteArrayInputStream(fileBytes);
    }
    
}

@Service
public class FastDFSClient {
    
    public static final String DEFAULT_GROUP = "group1";
    
    private StorageClient1 storageClient;
    
    public FastDFSClient() throws IOException, MyException {
        ClientGlobal.init("fdfs_client.conf");
        TrackerServer trackerServer = getTrackerServer();
        StorageServer storageServer = null;
        storageClient = new StorageClient1(trackerServer, storageServer);
    }
    
    public byte[] downloadFile(String fileId) throws IOException, MyException {
        String[] result = splitFileId(fileId);
        byte[] fileBytes = storageClient.download_file(result[0], result[1], new DownloadCallback() {
            @Override
            public int recv(long file_size, byte[] data, int bytes) {
                // do nothing
                return 0;
            }
        });
        return fileBytes;
    }
    
    private TrackerServer getTrackerServer() throws IOException {
        TrackerClient trackerClient = new TrackerClient();
        return trackerClient.getConnection();
    }
    
    private String[] splitFileId(String fileId) {
        return fileId.split("/", 2);
    }
    
}

在这个示例代码中，我们使用了FastDFS客户端来处理文件的上传和下载。在uploadFile方法中，我们首先使用MultipartFile类获取上传文件的输入流和文件名。然后，我们使用FastDFSClient类的uploadFile方法将文件上传到FastDFS服务器，并返回文件ID。在downloadFile方法中，我们使用FastDFSClient类的downloadFile方法从FastDFS服务器下载文件，并将其作为字节数组返回。在FileService中，我们将字节数组转换为InputStream对象，并将其作为下载文件的结果返回。