Java 使用OSS 文件分片上传MultipartFile代码

Java 使用OSS 文件分片上传MultipartFile代码可以分为以下几个步骤：
1. 引入OSS SDK依赖。
2. 初始化OSSClient对象。
3. 设置分片大小和并发数。
4. 创建InitiateMultipartUploadRequest对象并调用initiateMultipartUpload方法初始化分片上传任务。
5. 循环上传分片，创建UploadPartRequest对象并调用uploadPart方法上传分片。
6. 创建CompleteMultipartUploadRequest对象并调用completeMultipartUpload方法完成分片上传任务。

下面是Java使用OSS文件分片上传MultipartFile的代码示例：

// 引入OSS SDK依赖
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.model.*;

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

public class OSSFileUploadUtil {

    // 初始化OSSClient对象
    private static final String endpoint = "yourEndpoint";
    private static final String accessKeyId = "yourAccessKeyId";
    private static final String accessKeySecret = "yourAccessKeySecret";
    private static final String bucketName = "yourBucketName";
    private static final OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

    // 设置分片大小和并发数
    private static final int partSize = 1024 * 1024 * 1; // 1MB
    private static final int taskNum = 5;

    public static void uploadFileByMultipartFile(String localFilePath, String ossFilePath) throws IOException {
        // 创建InitiateMultipartUploadRequest对象并调用initiateMultipartUpload方法初始化分片上传任务
        InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, ossFilePath);
        InitiateMultipartUploadResult result = ossClient.initiateMultipartUpload(request);
        String uploadId = result.getUploadId();

        // 循环上传分片
        File file = new File(localFilePath);
        long fileLength = file.length();
        long partCount = fileLength / partSize + 1;
        if (fileLength % partSize == 0) {
            partCount--;
        }
        List<PartETag> partETags = new ArrayList<>();
        for (int i = 0; i < partCount; i++) {
            long startPos = i * partSize;
            long curPartSize = (i + 1 == partCount) ? (fileLength - startPos) : partSize;
            UploadPartRequest uploadPartRequest = new UploadPartRequest();
            uploadPartRequest.setBucketName(bucketName);
            uploadPartRequest.setKey(ossFilePath);
            uploadPartRequest.setUploadId(uploadId);
            uploadPartRequest.setPartNumber(i + 1);
            uploadPartRequest.setInputStream(FileUtil.getInputStreamByFile(file, startPos, curPartSize));
            uploadPartRequest.setPartSize(curPartSize);
            UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
            partETags.add(uploadPartResult.getPartETag());
        }

        // 创建CompleteMultipartUploadRequest对象并调用completeMultipartUpload方法完成分片上传任务
        CompleteMultipartUploadRequest completeMultipartUploadRequest = new CompleteMultipartUploadRequest(bucketName, ossFilePath, uploadId, partETags);
        ossClient.completeMultipartUpload(completeMultipartUploadRequest);
    }
}