Question

我正在尝试连接到我的AWS S3存储桶，以便根据这些链接上传文件＆＃39;说明。

http://docs.aws.amazon.com/AmazonS3/latest/dev/UploadObjSingleOpJava.html http://docs.aws.amazon.com/AWSSdkDocsJava/latest/DeveloperGuide/credentials.html#credentials-specify-provider

出于某种原因，当它试图实例化AmazonS3Client对象时，它会抛出一个被吞下的异常并退出我的Struts Action。因此，我没有太多信息需要调试。

我已尝试默认凭据配置文件（〜/ .aws /凭证）方法和显式密钥和访问密钥（新的BasicAWSCredentials（ access_key_id，secret_access_key）

/**
 * Uses the secret key and access key to return an object for accessing AWS features
 * @return BasicAWSCredentials
 */
public static BasicAWSCredentials getAWSCredentials() {
    final Properties props = new Properties();
    try {
        props.load(Utils.class.getResourceAsStream("/somePropFile"));
        BasicAWSCredentials credObj = new BasicAWSCredentials(props.getProperty("accessKey"), 
                props.getProperty("secretKey"));
        return credObj;
    }  catch (IOException e) {
        log.error("getAWSCredentials IOException" + e.getMessage());
        return null;
    }
    catch (Exception e) {
        log.error("getAWSCredentials Exception: " + e.getMessage());
        e.printStackTrace();
        return null;
    }
}

*********代码尝试S3访问**********

try {
        AmazonS3 s3client = new AmazonS3Client(Utils.getAWSCredentials());
        //AmazonS3 s3client = new AmazonS3Client(new ProfileCredentialsProvider());
        String fileKey = "catering/" + catering.getId() + fileUploadsFileName.get(i);

        System.out.println("Uploading a new object to S3 from a file\n");
        s3client.putObject(new PutObjectRequest(
                                                 Utils.getS3BucketName(), 
                                                 fileKey, file));
        // Save Attachment record
        Attachment newAttach = new Attachment();
        newAttach.setFile_key(fileKey);
        newAttach.setFilename(fileUploadsFileName.get(i));
        newAttach.setFiletype(fileUploadsContentType.get(i));
        newAttach = aDao.add(newAttach);

} 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.");
        System.out.println("Error Message:    " + ase.getMessage());
        System.out.println("HTTP Status Code: " + ase.getStatusCode());
        System.out.println("AWS Error Code:   " + ase.getErrorCode());
        System.out.println("Error Type:       " + ase.getErrorType());
        System.out.println("Request ID:       " + ase.getRequestId());
        fileErrors.add(fileUploadsFileName.get(i));
    } catch (AmazonClientException ace) {
        System.out.println("Caught an AmazonClientException, which " +
                                "means the client encountered " +
                                "an internal error while trying to " +
                                "communicate with S3, " +
                                "such as not being able to access the network.");
        System.out.println("Error Message: " + ace.getMessage());
        fileErrors.add(fileUploadsFileName.get(i));
    } catch(Exception e) {
    System.out.println("Error Message: " + e.getMessage());
}

它永远不会超过AmazonS3 s3client = new AmazonS3Client(Utils.getAWSCredentials());行。我已验证BasicAWSCredentials对象包含正确的字段值。基于此信息可能会出现阻止S3客户端连接的问题？

**编辑**

我在生成的堆栈跟踪中发现了这个看似有用的信息：

org.apache.tomcat.util.threads.TaskThread $ WrappingRunnable.run（TaskThread.java:61）在java.lang.Thread.run（Thread.java:745）引起： java.lang.NoClassDefFoundError：无法初始化类 com.amazonaws.ClientConfiguration at com.amazonaws.services.s3.AmazonS3Client。（AmazonS3Client.java:384）在 gearup.actions.CateringController.assignAttachments（CateringController.java:176）在 gearup.actions.CateringController.update（CateringController.java:135）

之前我尝试过跟随创建ClientConfiguration对象并将协议设置为HTTP的演示。但是我遇到了一个调用new ClientConfiguration();构造函数抛出NullPointerException的问题。我在这里错过了一些要求吗？

Answer 1

这很奇怪，因为aws-java-sdk-s3明确依赖于asw-java-sdk-core（请参阅pom.xml）。这里有点腥对我而言，事实证明这是一个apache httpclient版本的冲突（我的一个POM中的旧版本比一个亚马逊图书馆使用的版本更多。）我从其他人那里听到类似的冲突，例如jackson。

对于这种情况下的任何人，我建议您在Eclipse中打开Dependency hierarchy时查看POM.xml（或使用mvn dependency:tree。有关详细信息，请参阅here ）。

另外，请检查AWS抛出的第一条错误消息。它似乎并未作为所有其他堆栈跟踪中的原因链接，这只会告诉您类似java.lang.NoClassDefFoundError: Could not initialize class com.amazonaws.http.AmazonHttpClient的内容。

Answer 2

看起来您的项目缺少某些依赖项。

您清楚地在项目中配置了aws-java-sdk-s3 jar，因为它解析了AmazonS3Client，但这个jar也依赖于aws-java-sdk-core。您需要将核心jar添加到类路径中。

AmazonS3Client无法连接

2 个答案: