AWS Java SDK 1.9.3
在 Java 服务器应用程序中从 AWS S3 下载许多大文件 （~3Gb） 时，我不时收到 SocketTimeoutException，如下所示：
Caused by: com.amazonaws.AmazonClientException: Unable to store object contents to disk: Read timed out
at com.amazonaws.services.s3.internal.ServiceUtils.downloadObjectToFile(ServiceUtils.java:270)
at com.amazonaws.services.s3.internal.ServiceUtils.retryableDownloadS3ObjectToFile(ServiceUtils.java:344)
at com.amazonaws.services.s3.transfer.TransferManager$2.call(TransferManager.java:737)
... 4 more
Caused by: java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:152)
at java.net.SocketInputStream.read(SocketInputStream.java:122)
at sun.security.ssl.InputRecord.readFully(InputRecord.java:442)
at sun.security.ssl.InputRecord.readV3Record(InputRecord.java:554)
at sun.security.ssl.InputRecord.read(InputRecord.java:509)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:927)
at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:884)
at sun.security.ssl.AppInputStream.read(AppInputStream.java:102)
at org.apache.http.impl.io.AbstractSessionInputBuffer.read(AbstractSessionInputBuffer.java:198)
at org.apache.http.impl.io.ContentLengthInputStream.read(ContentLengthInputStream.java:178)
at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:137)
at com.amazonaws.internal.SdkFilterInputStream.read(SdkFilterInputStream.java:73)
at com.amazonaws.event.ProgressInputStream.read(ProgressInputStream.java:151)
at com.amazonaws.internal.SdkFilterInputStream.read(SdkFilterInputStream.java:73)
at com.amazonaws.internal.SdkFilterInputStream.read(SdkFilterInputStream.java:73)
at com.amazonaws.internal.SdkFilterInputStream.read(SdkFilterInputStream.java:73)
at com.amazonaws.event.ProgressInputStream.read(ProgressInputStream.java:151)
at java.security.DigestInputStream.read(DigestInputStream.java:161)
at com.amazonaws.services.s3.internal.DigestValidationInputStream.read(DigestValidationInputStream.java:59)
at com.amazonaws.internal.SdkFilterInputStream.read(SdkFilterInputStream.java:73)
at java.io.FilterInputStream.read(FilterInputStream.java:107)
at com.amazonaws.services.s3.internal.ServiceUtils.downloadObjectToFile(ServiceUtils.java:265)
... 6 more
我使用 3 个线程从 S4 下载文件，所有线程都使用相同的 TransferManager 实例。如前所述，我使用的是 AWS 开发工具包 1.9.3，并且只是不时收到此类异常。代码如下：
...
Download d = transferManager.download(currentBucket, remoteFileName, new File(tmpName));
d.waitForCompletion();
...
是SDK的问题吗？也许是v1.9.3？
除了增加ClientConfiguration socketTimeout之外，还有什么解决方案吗？
以下是我在 AWS 开发工具包 1.9.3 中可以执行的操作：
ClientConfiguration config = new ClientConfiguration();
config.setConnectionTimeout(connectionTimeout);
config.setSocketTimeout(readTimeout);
AmazonS3 s3 = new AmazonS3Client(credentials, config);