OSS如何实现Object的分块上传

在Java中实现对象的分块上传，尤其是针对大文件上传到云存储服务（如阿里云OSS - Object Storage Service）时，是非常实用的功能。这可以提高上传的稳定性和效率，特别是在网络环境不稳定的情况下。以下是一个使用阿里云OSS SDK进行分块上传的基本示例代码：

首先，确保你已经添加了阿里云OSS SDK的依赖到你的项目中。如果你使用的是Maven，可以在pom.xml中添加如下依赖：

<dependency>
    <groupId>com.aliyun.oss</groupId>
    <artifactId>aliyun-sdk-oss</artifactId>
    <version>3.10.2</version> <!-- 请检查并使用最新版本 -->
</dependency>

然后，你可以使用以下Java代码来实现分块上传：

import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.model.CompleteMultipartUploadRequest;
import com.aliyun.oss.model.InitiateMultipartUploadRequest;
import com.aliyun.oss.model.InitiateMultipartUploadResult;
import com.aliyun.oss.model.UploadPartRequest;
import com.aliyun.oss.model.UploadPartResult;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class OSSChunkUpload {

    public static void main(String[] args) throws IOException {
        String endpoint = "<yourEndpoint>";
        String accessKeyId = "<yourAccessKeyId>";
        String accessKeySecret = "<yourAccessKeySecret>";
        String bucketName = "<yourBucketName>";
        String objectName = "<yourObjectName>";
        String filePath = "<yourFilePath>";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

        try {
            // 初始化分片上传
            InitiateMultipartUploadRequest initiateMultipartUploadRequest = new InitiateMultipartUploadRequest(bucketName, objectName);
            InitiateMultipartUploadResult result = ossClient.initiateMultipartUpload(initiateMultipartUploadRequest);
            String uploadId = result.getUploadId();

            // 计算分片大小和数量
            File file = new File(filePath);
            long partSize = 1 * 1024 * 1024; // 每个分片大小为1MB，可以根据需要调整
            long fileLength = file.length();
            int partCount = (int) (fileLength / partSize);
            if (fileLength % partSize != 0) {
                partCount++;
            }

            // 分片上传
            List<UploadPartResult> uploadPartResults = new ArrayList<>();
            FileInputStream fis = new FileInputStream(file);
            for (int i = 0; i < partCount; i++) {
                long skipBytes = partSize * i;
                fis.skip(skipBytes);
                byte[] bytes = new byte[(int) Math.min(partSize, fileLength - skipBytes)];
                fis.read(bytes);

                UploadPartRequest uploadPartRequest = new UploadPartRequest()
                        .withBucketName(bucketName)
                        .withKey(objectName)
                        .withUploadId(uploadId)
                        .withPartNumber(i + 1)
                        .withInputStream(new ByteArrayInputStream(bytes))
                        .withPartSize(bytes.length);
                UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
                uploadPartResults.add(uploadPartResult);
            }
            fis.close();

            // 完成分片上传
            CompleteMultipartUploadRequest completeRequest = new CompleteMultipartUploadRequest(bucketName, objectName, uploadId);
            List<PartETag> partETags = new ArrayList<>();
            for (UploadPartResult uploadPartResult : uploadPartResults) {
                partETags.add(new PartETag(uploadPartResult.getPartNumber(), uploadPartResult.getETag()));
            }
            completeRequest.setPartETags(partETags);
            ossClient.completeMultipartUpload(completeRequest);
            System.out.println("分片上传完成");
        } catch (Exception e) {
            System.out.println("分片上传失败：" + e.getMessage());
            ossClient.abortMultipartUpload(new AbortMultipartUploadRequest(bucketName, objectName, uploadId));
        } finally {
            // 关闭OSSClient。
            ossClient.shutdown();
        }
    }
}

请将<yourEndpoint>、<yourAccessKeyId>、<yourAccessKeySecret>、<yourBucketName>、<yourObjectName>以及<yourFilePath>替换为你自己的实际值。

这段代码首先初始化一个分片上传请求，然后根据文件大小计算出需要上传的分片数，并逐个上传这些分片。最后，通过调用completeMultipartUpload方法来完成整个文件的上传。如果在上传过程中遇到任何错误，可以通过调用abortMultipartUpload来取消正在进行的分片上传。