It seems that Eclipse's export jar functionality is broken. But since maven is working properly, I assume the issue is resolved.

For the other error, can you post the source code of the main() method somewhere?
There are some hints how to resolve the issue in the exceptions (use of .returns() annotation, missing type parameters). Maybe one of those hints resolves the issues already.

On Tue, Nov 3, 2015 at 2:14 PM, Saleh <e106625@hotmail.com> wrote:
Hi Stephan,
Thanx for the response. Actually I am using Maven and below are all Flink
dependencies I have in my pom.xml file.

    /
                <dependency>
                        <groupId>org.apache.flink</groupId>
                        <artifactId>flink-core</artifactId>
                        <version>0.9.1</version>
                        <scope>provided</scope>
                </dependency>
                <dependency>
                        <groupId>org.apache.flink</groupId>
                        <artifactId>flink-streaming-core</artifactId>
                        <version>0.9.1</version>
                </dependency>
                <dependency>
                        <groupId>org.apache.flink</groupId>
                        <artifactId>flink-clients</artifactId>
                        <version>0.9.1</version>
                </dependency>
                <dependency>
                        <groupId>org.apache.flink</groupId>
                        <artifactId>flink-connector-kafka</artifactId>
                        <version>0.9.1</version>
                </dependency>
                <dependency>
                    <groupId>org.apache.flink</groupId>
                    <artifactId>flink-java8</artifactId>
                    <version>0.9.1</version>
    </dependency>/

The problem is when I create a jar file using eclipse's *export*
functionality, I get the previously mentioned *Could not load the task's
invokable class* exception. And when I create the jar file with Maven's *mvn
clean package* command, I get different exception shown below:

    /org.apache.flink.api.common.functions.InvalidTypesException: The return
type of function     'kafkaFlinkWordCount(FlinkWordCount.java:53)' could not
be determined automatically, due to type erasure. You can give type
information hints by using the returns(...) method on the result of the
transformation call, or by letting your function implement the
'ResultTypeQueryable' interface.
        at
org.apache.flink.streaming.api.datastream.DataStream.getType(DataStream.java:207)
        at
org.apache.flink.streaming.api.datastream.DataStream.addSink(DataStream.java:1336)
        at
org.apache.flink.streaming.api.datastream.DataStream.print(DataStream.java:1029)/

The error message continues and near to the end there is this kind of
message:

    /at org.apache.flink.client.CliFrontend.main(CliFrontend.java:920)
    Caused by: org.apache.flink.api.common.functions.InvalidTypesException:
The generic type parameters      of 'Tuple2' are missing.
    It seems that your compiler has not stored them into the .class file.
    Currently, only the Eclipse JDT compiler preserves the type information
necessary to use the lambdas      feature type-safely.
    See the documentation for more information about how to compile jobs
containing lambda expressions./

I tried to use *flink-0.10-SNAPSHORT* as you suggested, but it introduced a
syntax error in my source code with this message:

    */The method groupBy(0) os undefined for the type
SingleOutputStreamOperation<Tuple2<String, Integer>, capture #1 of ?>/*



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