How to connect Process and Operator?

prayerslayerprayerslayer Member Posts: 3 Contributor I
edited November 2018 in Help

I'm very aware of the fact that it's not being welcomed to ask questions regarding the chaining of operators programatically. However, I need to do this for my thesis and hope that you'll kindly oversee it this time.

Everything works really well already, but I couldn't figure out how to connect the output of an operator to a result port of my process. Could anyone give me a hint? It's this part:


I tried to look for ports of the RootOperator, but there was no output:

System.out.println("looking for process ports");
for (String port : process.getRootOperator().getInputPorts().getPortNames())
Am I able to add it anyway? Or somewhere else?

The actual problem I have is that after the process finished, I can't access the result (because there is none, I guess).
INFO: Process finished successfully after 3 s
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
at java.util.ArrayList.rangeCheck(ArrayList.java:570)
at java.util.ArrayList.get(ArrayList.java:348)
at com.rapidminer.operator.IOContainer.getElementAt(IOContainer.java:112)
at BackendTest.main(BackendTest.java:128)
At this line:
if (process_result.getElementAt(0) instanceof ExampleSet) { ... }
Thanks in advance!


  • Options
    Marco_BoeckMarco_Boeck Administrator, Moderator, Employee, Member, University Professor Posts: 1,996 RM Engineering

    you may ask whatever you want to know - we just encourage others to use the GUI approach because it is much easier. However if there's a reason why you need to do it programatically, it is perfectly fine ;)

    I put together a quick example for you:

    This is the example process with an operator not connected to an output port.

    <?xml version="1.0" encoding="UTF-8" standalone="no"?>
    <process version="5.2.003">
      <operator activated="true" class="process" compatibility="5.2.003" expanded="true" name="Process">
        <parameter key="logverbosity" value="init"/>
        <parameter key="random_seed" value="2001"/>
        <parameter key="send_mail" value="never"/>
        <parameter key="notification_email" value=""/>
        <parameter key="process_duration_for_mail" value="30"/>
        <parameter key="encoding" value="SYSTEM"/>
        <parameter key="parallelize_main_process" value="false"/>
        <process expanded="true" height="639" width="950">
          <operator activated="true" class="retrieve" compatibility="5.2.003" expanded="true" height="60" name="Retrieve" width="90" x="45" y="30">
            <parameter key="repository_entry" value="//Samples/data/Iris"/>
          <portSpacing port="source_input 1" spacing="0"/>
          <portSpacing port="sink_result 1" spacing="0"/>
    This line connects the operator referenced by its name to the first output port of the process:

    And in case you need a procedure for input ports as well, you can find it here.

  • Options
    prayerslayerprayerslayer Member Posts: 3 Contributor I
    Thanks a lot, works like a charm :)
Sign In or Register to comment.