如何获取AmazonS3对象的最新版本ID

Question

给定一个有效的Amazon S3路径，该路径指定获取哪个桶、哪个文件的版本ID，如何使用AWS SDK JAVA API获取最新版本ID？

我尝试在中搜索APIhttps://sdk.amazonaws.com/java/api/latest/，但未找到返回版本ID的API。

函数签名为String getLatestVersionID(String S3Path);

Thx

Answer 1

您可以通过调用GetObjectRequest对象versionId方法来设置版本Id值。这是这个的代码：

package com.example.s3;
// snippet-start:[s3.java2.getobjectdata.import]
import software.amazon.awssdk.core.ResponseBytes;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.GetObjectResponse;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
// snippet-end:[s3.java2.getobjectdata.import]
/**
* To run this AWS code example, ensure that you have setup your development environment, including your AWS credentials.
*
* For information, see this documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class GetObjectData {
public static void main(String[] args) {
final String USAGE = "n" +
"Usage:n" +
"    GetObjectData <bucketName> <keyName> <path>nn" +
"Where:n" +
"    bucketName - the Amazon S3 bucket name. nn"+
"    keyName - the key name. nn"+
"    path - the path where the file is written to. nn";
if (args.length != 3) {
System.out.println(USAGE);
System.exit(1);
}
String bucketName = args[0];
String keyName = args[1];
String path = args[2];
Region region = Region.US_EAST_1;
S3Client s3 = S3Client.builder()
.region(region)
.build();
getObjectBytes(s3,bucketName,keyName, path);
s3.close();
}
// snippet-start:[s3.java2.getobjectdata.main]
public static void getObjectBytes (S3Client s3, String bucketName, String keyName, String path ) {
try {
GetObjectRequest objectRequest = GetObjectRequest
.builder()
.key(keyName)
.versionId("<Set Version ID>")
.bucket(bucketName)
.build();
ResponseBytes<GetObjectResponse> objectBytes = s3.getObjectAsBytes(objectRequest);
byte[] data = objectBytes.asByteArray();
// Write the data to a local file
File myFile = new File(path );
OutputStream os = new FileOutputStream(myFile);
os.write(data);
System.out.println("Successfully obtained bytes from an S3 object");
os.close();
} catch (IOException ex) {
ex.printStackTrace();
} catch (S3Exception e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
// snippet-end:[s3.java2.getobjectdata.main]
}
}