Github user rmetzger commented on a diff in the pull request:
https://github.com/apache/incubator-flink/pull/94#discussion_r17476806
--- Diff:
flink-java/src/main/java/org/apache/flink/api/java/io/RemoteCollectorOutputFormat.java
---
@@ -0,0 +1,110 @@
+package org.apache.flink.api.java.io;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.IOException;
+import java.rmi.AccessException;
+import java.rmi.NotBoundException;
+import java.rmi.RemoteException;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.registry.Registry;
+
+import org.apache.flink.api.common.io.OutputFormat;
+import org.apache.flink.configuration.Configuration;
+
+/**
+ * An output format that sends results through JAVA RMI to an
+ * {@link IRemoteCollector} implementation. The client has to provide an
+ * implementation of {@link IRemoteCollector} and has to write it's plan's
+ * output into an instance of {@link RemoteCollectorOutputFormat}. Further
in
+ * the client's VM parameters -Djava.rmi.server.hostname should be set to
the
+ * own IP address.
+ */
+public class RemoteCollectorOutputFormat<T> implements OutputFormat<T> {
+
+ private static final long serialVersionUID = 1922744224032398102L;
+
+ /**
+ * The reference of the {@link IRemoteCollector} object
+ */
+ private IRemoteCollector<T> remoteCollector;
+
+ /**
+ * Config parameter for the remote's port number
+ */
+ public static final String PORT = "port";
+ /**
+ * Config parameter for the remote's address
+ */
+ public static final String REMOTE = "remote";
+ /**
+ * An id used necessary for Java RMI
+ */
+ public static final String ID = "RemoteCollector";
+
+ @SuppressWarnings("unchecked")
+ @Override
+ /**
+ * This method receives the Configuration object, where the fields
"remote" and "port" must be set.
+ */
+ public void configure(Configuration parameters) {
+
+ Registry registry = null;
+ // get the remote's RMI Registry
+ try {
+ registry =
LocateRegistry.getRegistry(parameters.getString(REMOTE, "localhost"),
+ parameters.getInteger(PORT, 8888));
+ } catch (RemoteException e) {
+ e.printStackTrace();
+ }
+
+ // try to get an intance of an IRemoteCollector implementation
+ try {
+ this.remoteCollector = (IRemoteCollector<T>)
registry.lookup(ID);
+ } catch (AccessException e) {
+ e.printStackTrace();
--- End diff --
Maybe its easier here to just catch Throwable here?
In addition, its very important to handle exceptions properly. In this case
I would suggest to rethrow them as runtime exceptions.
If you just write the stacktrace to stdout, users might not be able to find
out it (the message is missing).
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