https://sandyghai.github.io/AWS-S3-Multipart-Upload-Using-Presigned-Url/可以生成预签名,分片上传时,每一个分片都可以生成预签名
实际上每个地址都可以生成预签名
```
Aws4PresignerParams params = Aws4PresignerParams.builder()
// .expirationTime(storageTemplate.processExpires(expires))
.awsCredentials(storageTemplate.getCredentials())
.signingName("s3")
.expirationTime(Instant.now().plusSeconds(storageTemplate.getExpiresOrDefault(expires)))
.signingRegion(Region.of(storageTemplate.processRegion(region)))
.build();
SdkHttpFullRequest request = SdkHttpFullRequest.builder()
.encodedPath(storageTemplate.processPath(bucketName, key) + "?uploadId=" + uploadId + "&partNumber=" + partNumber)
.host(storageTemplate.getHost())
.method(SdkHttpMethod.PUT)
.protocol(storageTemplate.getProtocol())
.build();
return AwsS3V4Signer.create().presign(request, params).getUri().toString();
```