* @return public static File downloadFileToLocalDir(String bucket, String key, String localDir) { logger.info("Download object from s3, bucket: {}, key: {}, to local dir: {}", bucket, key, localDir); try { S3Object s3Object = s3Client.getObject(bucket, key); File fileDir = new File(localDir); if (!fileDir.exists()) { fileDir.mkdirs(); File file = new File(localDir + key); OutputStream outputStream = new FileOutputStream(file); IOUtils.copy(s3Object.getObjectContent(), outputStream); s3Object.getObjectContent().close(); outputStream.close(); return file; } catch (Exception e) { logger.error("Fail to download file from amazon s3, bucket: {}, key: {}, to local dir: {}", bucket, key, localDir, e); throw new UdsRuntimeException(UdsErrorCode.INTERNAL_SERVER_ERROR, "Fail to download file from amazon s3, bucket: {}, key: {}, to local dir: {}", bucket, key, localDir);

对 Amazon S3 对象执行操作
https://docs.aws.amazon.com/zh_cn/sdk-for-java/v1/developer-guide/examples-s3-objects.html

使用 AWS SDK for Java 获取对象
https://docs.aws.amazon.com/zh_cn/AmazonS3/latest/dev/RetrievingObjectUsingJava.html

Interface AmazonS3
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3.html

使用 AWS SDK for Java 上传对象

以下示例将创建两个对象。第一个对象将一个文本字符串作为数据，第二对象是一个文件。该示例通过在对 AmazonS3Client.putObject() 的调用中直接指定存储桶名称、对象键和文本数据来创建第一个对象。该示例通过使用指定存储桶、对象键和文件路径的 PutObjectRequest 来创建第二个对象。PutObjectRequest 还指定 ContentType 标头和标题元数据。

// SPDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-s3-developer-guide/blob/master/LICENSE-SAMPLECODE.) import java.io.File; import java.io.IOException; import com.amazonaws.AmazonServiceException; import com.amazonaws.SdkClientException; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3ClientBuilder; import com.amazonaws.services.s3.model.ObjectMetadata; import com.amazonaws.services.s3.model.PutObjectRequest; public class UploadObject { public static void main(String[] args) throws IOException { String clientRegion = "*** Client region ***"; String bucketName = "*** Bucket name ***"; String stringObjKeyName = "*** String object key name ***"; String fileObjKeyName = "*** File object key name ***"; String fileName = "*** Path to file to upload ***"; try { AmazonS3 s3Client = AmazonS3ClientBuilder.standard() .withRegion(clientRegion) .withCredentials(new ProfileCredentialsProvider()) .build(); // Upload a text string as a new object. s3Client.putObject(bucketName, stringObjKeyName, "Uploaded String Object"); // Upload a file as a new object with ContentType and title specified. PutObjectRequest request = new PutObjectRequest(bucketName, fileObjKeyName, new File(fileName)); ObjectMetadata metadata = new ObjectMetadata(); metadata.setContentType("plain/text"); metadata.addUserMetadata("x-amz-meta-title", "someTitle"); request.setMetadata(metadata); s3Client.putObject(request); catch(AmazonServiceException e) { // The call was transmitted successfully, but Amazon S3 couldn't process // it, so it returned an error response. e.printStackTrace(); catch(SdkClientException e) { // Amazon S3 couldn't be contacted for a response, or the client // couldn't parse the response from Amazon S3. e.printStackTrace();

Interface AmazonS3
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3.html

使用 AWS SDK for Java 上传对象
https://docs.aws.amazon.com/zh_cn/AmazonS3/latest/dev/UploadObjSingleOpJava.html