我可以更新现有的Amazon S3对象吗？

在Amazon S3中更新现有对象与首先创建对象没有什么不同，即，使用相同的PUT
Object
操作上载对象，并将覆盖现有对象（如果不受其他方式的保护，例如通过使用存储桶策略或对象版本控制）

您可以在使用适用于Java的AWS开发工具包上载对象中找到完整的代码示例，主要部分可以归结为：

AmazonS3 s3client = new AmazonS3Client(new PropertiesCredentials(        S3Sample.class.getResourceAsStream(     "AwsCredentials.properties")));try {    System.out.println("Uploading a new object to S3 from a filen");    File file = new File(uploadFileName);    s3client.putObject(new PutObjectRequest(       bucketName, keyName, file)); } catch (AmazonServiceException ase) {    System.out.println("Caught an AmazonServiceException, which " + "means your request made it " + "to Amazon S3, but was rejected with an error response" + " for some reason.");    // ... error handling based on exception details}