java 大文件上传oss

以下是Java实现上传大文件到OSS的步骤和代码示例：

1. 引入OSS SDK依赖

在Maven项目中，可以在pom.xml文件中添加以下依赖：

<dependency>
    <groupId>com.aliyun.oss</groupId>
    <artifactId>aliyun-sdk-oss</artifactId>
    <version>2.8.3</version>
</dependency>

2. 初始化OSSClient

String endpoint = "yourEndpoint";
String accessKeyId = "yourAccessKeyId";
String accessKeySecret = "yourAccessKeySecret";
String bucketName = "yourBucketName";

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

// 判断Bucket是否存在，不存在则创建
if (!ossClient.doesBucketExist(bucketName)) {
    ossClient.createBucket(bucketName);
}

3. 分片上传文件

String objectName = "yourObjectName"; // 上传到OSS的文件名
String filePath = "yourFilePath"; // 本地文件路径

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

// 设置分片大小
final long partSize = 1024 * 1024 * 1; // 1MB

// 计算分片数目
File file = new File(filePath);
long fileLength = file.length();
int partCount = (int) (fileLength / partSize);
if (fileLength % partSize != 0) {
    partCount++;
}

// 上传分片
List<PartETag> partETags = new ArrayList<>();
for (int i = 0; i < partCount; i++) {
    long startPos = i * partSize;
    long curPartSize = (i + 1 == partCount) ? (fileLength - startPos) : partSize;

    FileInputStream fis = new FileInputStream(file);
    fis.skip(startPos);

    UploadPartRequest uploadPartRequest = new UploadPartRequest();
    uploadPartRequest.setBucketName(bucketName);
    uploadPartRequest.setKey(objectName);
    uploadPartRequest.setUploadId(uploadId);
    uploadPartRequest.setInputStream(fis);
    uploadPartRequest.setPartSize(curPartSize);
    uploadPartRequest.setPartNumber(i + 1);

    UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
    partETags.add(uploadPartResult.getPartETag());
    fis.close();
}

// 完成分片上传
CompleteMultipartUploadRequest completeMultipartUploadRequest = new CompleteMultipartUploadRequest(bucketName, objectName, uploadId, partETags);
ossClient.completeMultipartUpload(completeMultipartUploadRequest);

4. 关闭OSSClient

ossClient.shutdown();