我为Apache Beam实现了UnboundedSource，需要与需要256位加密的服务器进行通信。我可以在本地运行作业时使用它（通过在我的本地$JAVA_HOME/jre/lib/security目录中安装无限强度策略文件[1]。
我的问题是在Google Cloud Platform [2]中运行的Dataflow作业中使用此问题时尝试使用此UnboundedSource？
是否可以配置数据流作业以使用无限制的安全策略文件，或者GCP不支持该功能？
尝试在GCP中运行时遇到的错误（没有无限强度政策文件）是handshake error
exception: "java.util.concurrent.ExecutionException: java.net.ConnectException: Received fatal alert: handshake_failure
at com.google.common.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:299)
at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:286)
at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116)
at com.urbanairship.connect.client.StreamConnection.connect(StreamConnection.java:212)
at com.urbanairship.connect.client.StreamConnection.begin(StreamConnection.java:145)
at com.urbanairship.connect.client.StreamConnection.read(StreamConnection.java:122)
at com.urbanairship.connect.client.StreamConsumeTask.transitionToReading(StreamConsumeTask.java:138)
at com.urbanairship.connect.client.StreamConsumeTask.stream(StreamConsumeTask.java:100)
at com.urbanairship.connect.client.StreamConsumeTask.run(StreamConsumeTask.java:83)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Received fatal alert: handshake_failure
at com.ning.http.client.providers.netty.request.NettyConnectListener.onFutureFailure(NettyConnectListener.java:133)
at com.ning.http.client.providers.netty.request.NettyConnectListener.access$200(NettyConnectListener.java:37)
at com.ning.http.client.providers.netty.request.NettyConnectListener$1.operationComplete(NettyConnectListener.java:104)
at org.jboss.netty.channel.DefaultChannelFuture.notifyListener(DefaultChannelFuture.java:409)
at org.jboss.netty.channel.DefaultChannelFuture.notifyListeners(DefaultChannelFuture.java:395)
at org.jboss.netty.channel.DefaultChannelFuture.setFailure(DefaultChannelFuture.java:362)
at org.jboss.netty.handler.ssl.SslHandler.setHandshakeFailure(SslHandler.java:1460)
at org.jboss.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1314)
at org.jboss.netty.handler.ssl.SslHandler.decode(SslHandler.java:852)
at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:425)
at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:303)
at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:268)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:255)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:88)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:108)
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:337)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:89)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178)
at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
... 3 more
正如在另一个question中建议的那样，我尝试使用反射来覆盖安全策略以允许无限长度的密钥，但这不起作用，其中一条评论提到反射黑客对Java 8不起作用（我相信由于变量被更改为final）。
在我的工作中运行此块无效...
final Class<?> jceSecurity = Class.forName("javax.crypto.JceSecurity");
final Class<?> cryptoPermissions = Class.forName("javax.crypto.CryptoPermissions");
final Class<?> cryptoAllPermission = Class.forName("javax.crypto.CryptoAllPermission");
final Field isRestrictedField = jceSecurity.getDeclaredField("isRestricted");
isRestrictedField.setAccessible(true);
final Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(isRestrictedField, isRestrictedField.getModifiers() & ~Modifier.FINAL);
isRestrictedField.set(null, false);
final Field defaultPolicyField = jceSecurity.getDeclaredField("defaultPolicy");
defaultPolicyField.setAccessible(true);
final PermissionCollection defaultPolicy = (PermissionCollection) defaultPolicyField.get(null);
final Field perms = cryptoPermissions.getDeclaredField("perms");
perms.setAccessible(true);
((Map<?, ?>) perms.get(defaultPolicy)).clear();
final Field instance = cryptoAllPermission.getDeclaredField("INSTANCE");
instance.setAccessible(true);
defaultPolicy.add((Permission) instance.get(null));
[1] http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html
[2] https://cloud.google.com/dataflow