AWS S3 Java：d​​osObjectExist结果为403：禁止

使用AWS开发工具包与S3存储桶进行交互的Java程序遇到问题.

这是我用来创建S3客户端的代码：

public S3StorageManager(S3Config config) throws StorageException {

   BasicAWSCredentials credentials = new BasicAWSCredentials(myAccessKey(), mySecretKey());
   AWSStaticCredentialsProvider provider = new AWSStaticCredentialsProvider(credentials);

   this.s3Client = AmazonS3ClientBuilder
        .standard()
        .withCredentials(provider)
        .withRegion(myRegion)
        .build();

当我尝试下载文件时,在开始下载之前,请使用以下命令检查文件是否存在：

s3Client.doesObjectExists(bucketName, objectName);

这是我得到403：禁止的地方.
奇怪的是,仅当我尝试在同一会话中执行上传之前尝试执行对象存在检查时,才会引发此问题.
换句话说,在初始化s3Client之后：
 -如果我首先尝试检查对象是否存在,则会引发FORBIDDEN问题；
 -如果我第一次执行文件上传,则可以正常工作,然后进行任何对象存在检查也可以；

这是我的堆栈跟踪：

com.amazonaws.services.s3.model.AmazonS3Exception: Forbidden (Service: Amazon S3; Status Code: 403; Error Code: 403 Forbidden; Reques
t ID: A23BB805491E411F)
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleErrorResponse(AmazonHttpClient.java:1588) ~[aws-java-sdk-core-1.
11.128.jar:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1258) ~[aws-java-sdk-core-1.11
.128.jar:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1030) ~[aws-java-sdk-core-1.11.128
.jar:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:742) ~[aws-java-sdk-core-1.11.128.jar:
?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:716) ~[aws-java-sdk-core-1.11.1
28.jar:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:699) ~[aws-java-sdk-core-1.11.128.jar:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:667) ~[aws-java-sdk-core-1.11.128.jar
:?]
        at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:649) ~[aws-java-sdk-core-1.1
1.128.jar:?]
        at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:513) ~[aws-java-sdk-core-1.11.128.jar:?]
        at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4169) ~[aws-java-sdk-s3-1.11.128.jar:?]
        at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4116) ~[aws-java-sdk-s3-1.11.128.jar:?]
        at com.amazonaws.services.s3.AmazonS3Client.getObjectMetadata(AmazonS3Client.java:1237) ~[aws-java-sdk-s3-1.11.128.jar:?]
        at com.amazonaws.services.s3.AmazonS3Client.getObjectMetadata(AmazonS3Client.java:1213) ~[aws-java-sdk-s3-1.11.128.jar:?]
        at com.amazonaws.services.s3.AmazonS3Client.doesObjectExist(AmazonS3Client.java:1272) ~[aws-java-sdk-s3-1.11.128.jar:?]

另一个奇怪的是,所有这些问题都是在我将Java程序移至EC2远程计算机时开始的.
如果我在本地计算机上执行它,则S3交互可以正常工作.
但是,我认为问题不取决于IAM角色,因为我使用的是AWSStaticCredentialsProvider.

解决方法:

您的凭据可能是正确的,但是如果您没有设置正确的IAM策略,您仍然会被禁止.要检查s3中的对象,您需要：

{
    "Version":"2012-10-17",
    "Statement":[
        {
            "Effect":"Allow",
            "Action":[
            "s3:ListBucket"
            ],
            "Resource":["arn:aws:s3:::examplebucket/*"]
        },
        {
            "Effect":"Allow",
            "Action":[
            "s3:GetObject"
            ],
          "Resource":["arn:aws:s3:::examplebucket/*"]
        }
    ]
}

标签：java,amazon-web-services,amazon-ec2,amazon-s3,http-status-code-403
来源： https://codeday.me/bug/20191009/1878330.html