topic Re: How to use the iterate flow from a tJava component? in Talend Studio

How to use the iterate flow from a tJava component?

Red1 — Tue, 27 Mar 2018 17:56:16 GMT

I just noticed last week that the tJava component has an iterate flow. Has anyone used this before? Is there an example of how to use it? Please note that I am not talking about the tJavaFlex component.

Just for clarification I am adding this photo and I modified the subject

Notice how it is the tJava Component that has the iterate flow

Re: How to use the iterate flow from a tJava component?

manodwhb — Wed, 28 Mar 2018 08:01:16 GMT

@Red,can you the below link may be usefull.

http://bekwam.blogspot.in/2012/08/iterating-over-java-collection-with.html

Re: How to use the iterate flow from a tJava component?

TRF — Wed, 28 Mar 2018 08:08:39 GMT

Hi,

Just like other components, use the iterate connection to connect tJava to a starting component such as tFileInputDelimited or others.

Have a look to the documentation for more details

https://help.talend.com/reader/lChEGrKIFb8DXl9sRsX~~A/UoOiqbEZUVnVX9rFcx02QQ

Re: How to use the iterate flow from a tJava component?

Red1 — Wed, 04 Apr 2018 18:15:42 GMT

I am trying to figure out why the tJava component has an iterate flow. Is it possible to use? See the picture that I added for clarification.

Re: How to use the iterate flow from a tJava component?

Anonymous — Wed, 04 Apr 2018 20:41:16 GMT

It acts similar to a tFlowToIterate. Let's say, you send 10 rows from a table to tJava and print something. You will only see that print once. You then iterate to another tJava where you can then print for each individual value.

Re: How to use the iterate flow from a tJava component?

Anonymous — Wed, 04 Apr 2018 20:43:13 GMT

Re: How to use the iterate flow from a tJava component?

Anonymous — Wed, 04 Apr 2018 20:44:00 GMT

I tried to grab row1 and got a null as expected, but after the iterate System.out.println(row1.newColumn) returns the values I wanted.

Re: How to use the iterate flow from a tJava component?

Red1 — Wed, 04 Apr 2018 21:37:51 GMT

Can I see how you configured tJava_3? What java does it contain? Are you using java to control it's Iterate flow?

Re: How to use the iterate flow from a tJava component?

Anonymous — Thu, 05 Apr 2018 18:44:34 GMT

I am doing nothing there, tjava is what it is. tJava is just a placeholder here. It cannot pass anything across but continue a flow. The behavioral benefit of using the iterate function is the ability to capture the row information coming out of your input. Again, this can be achieved using other components. The behavior is part of Talend and the java code it generates. You may be overcomplicating things.

What are you trying to achieve with this?

Re: How to use the iterate flow from a tJava component?

Anonymous — Thu, 05 Apr 2018 18:45:25 GMT

Re: How to use the iterate flow from a tJava component?

Red1 — Fri, 06 Apr 2018 00:08:59 GMT

So, there was noting in the other tJava_3 component controlling the iterator? I guess the iterator runs based on the number of rows that were passed in the row1 flow. Is there any way to control the iterator in the tJava_3 component?

Re: How to use the iterate flow from a tJava component?

Anonymous — Fri, 06 Apr 2018 16:20:56 GMT

No, whatever is in the tjava component would just run first. There would be no way to control the iteration from there.

Re: How to use the iterate flow from a tJava component?

Red1 — Fri, 06 Apr 2018 17:25:34 GMT

The overall goal of this post was to see how a tJava component controls the iterate flow. From our discussion I now understand that the iterate flow is based on the rows which were fed into the tJava component. There is no way control the iterator from inside the tJava component using java.

Re: How to use the iterate flow from a tJava component?

since_1995 — Wed, 24 Aug 2022 19:11:04 GMT

Can I use this result of tjava_3 in my subjob? Can this store all the rows ?