背景：

众所知周，AWS S3 client功能强大，能与各类符合OSS标准的存储进行工作。本项目中刚好用到ceph，就是直接使用S3 java client上传文件。在根据ceph官网的的一些文档操作时遇到一些问题，这里记录下来，仅供遇到类似问题的网友参考。

问题与解决方法

按照ceph https://docs.ceph.com/en/quincy/radosgw/s3/java/ 官网的示例，在本人环境中无法遍历bucket或者upload文件， 在多方搜索对比测试后发现，需要添加几个参数才行，目前不确定是否是因为本地ceph的设置导致的问题， 这里记录下来仅供参考。

 //  disable SSL cert checkString accessKey = "insert your access key here!";String secretKey = "insert your secret key here!";//具体的域名， 每个项目或者公司都不一样String cephHost = "http://cepha.b.com";System.setProperty(SDKGlobalConfiguration.DISABLE_CERT_CHECKING_SYSTEM_PROPERTY,"true");if (SDKGlobalConfiguration.isCertCheckingDisabled()){System.out.println("Cert checking is disabled");}// S3 Client configurationClientConfiguration config = new ClientConfiguration();// Not the standard "AWS3SignerType", maar expliciet signerTypeV2config.setSignerOverride("S3SignerType");// or else Amazon S3; Status Code: 403; Error Code: SignatureDoesNotMatch will happen. 这个也很重要，不然给putRequest 添加一些mata时会报SignatureDoesNotMatch的错误config.setSignerOverride("AWSS3V4SignerType");config.setProtocol(Protocol.HTTP);BasicAWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);AwsClientBuilder.EndpointConfiguration endpointConfiguration = new AwsClientBuilder.EndpointConfiguration(cephHost, "local-ceph");
// 重点就是这个 "local-ceph"， 不设置它，在本人项目中，可以list buckt但是不能upload fileAmazonS3 s3Client = AmazonS3ClientBuilder.standard().withClientConfiguration(config).withCredentials(new AWSStaticCredentialsProvider(credentials)).withEndpointConfiguration(endpointConfiguration).enablePathStyleAccess().disableChunkedEncoding().build();

对比一下ceph官网的文档

String accessKey = "insert your access key here!";
String secretKey = "insert your secret key here!";AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
AmazonS3 s3Client = new AmazonS3Client(credentials);
s3Client.setEndpoint("objects.dreamhost.com");

其他

在创建了AmazonS3 对象后记可以操作bucket中内容

 List buckets = s3Client.listBuckets();

上传文件，并带有meta信息，

try {ObjectMetadata metaData = new ObjectMetadata();Map userMetaData = new HashMap<>();userMetaData.put("key1", "val1");userMetaData.put("key2", "val2");userMetaData.put("key3", "val3");metaData.setUserMetadata(userMetaData);PutObjectRequest putObjReq = new PutObjectRequest(bucketName, fileKey, file);putObjReq.setMetadata(metaData);PutObjectResult result =  s3Client.putObject(putObjReq);log.info("upload result {}", result);} catch (Exception ex) {log.error("fail to  upload to fileKey {}, exMsg:{}",fileKey, ex.getMessage(), ex);}

如果上传的文件较大，使用TransferManager， 参看S3官方文档
https://docs.aws.amazon.com/zh_cn/sdk-for-java/v1/developer-guide/examples-s3-transfermanager.html

      PutObjectRequest putObjReq = new PutObjectRequest(bucketName, fileKey, file);putObjReq.setMetadata(metaData);TransferManager tm = TransferManagerBuilder.standard().withS3Client(s3Client).build();Upload upload = tm.upload(putObjReq, progressListener);log.info("start to upload file '{}' to fileKey:{},",file.getAbsolutePath(), fileKey);// wait for the upload to finish before continuing.upload.waitForCompletion();