topic Re: Read data from data input flow in Talend Studio

Read data from data input flow

Anonymous — Sat, 04 Nov 2017 11:58:42 GMT

Hi,

I am writing a custom component and want to use some input data. I use tFileInputDelimited and connect it with tMap to my component.

I now want to read every line of input and log it to the console. (Later I want to convert it and use it within my component, that is why tLogRow is not the right solution).

How can I do that?

I tried

IMetadataTable preMetadata = null;
 if ((node.getIncomingConnections()!=null)&&(node.getIncomingConnections().size()>0))
 preMetadata = node.getIncomingConnections().get(0).getMetadataTable();
 String inRowName = node.getIncomingConnections().get(0).getName(); 
 List<IMetadataColumn> columns = preMetadata.getListColumns();%>
 for (int i = 0; i < columns.size(); i++){
 IMetadataColumn column = columns.get(i);%> 
 System.out.println(String.valueOf(<%=inRowName%>.<%=column.getLabel() %>));
 <% 
 }

but it keeps printing 'null'..

When I run the same job but with tLogRow at the end (tFileInputDelimited - tMap - tLogRow), it logs every value on the console so I assume there is now problem with loading the file.

Thanks for your help!

Re: Read data from data input flow

Anonymous — Mon, 06 Nov 2017 04:00:57 GMT

Hello,

There is a component tfileinputfullrow in talend which can read a file row by row and send complete rows of data as defined in the schema to the next component via a Row link.

Have you tried to use this input component before your custom component to see if it works?

Best regards

Sabrina

Re: Read data from data input flow

Anonymous — Mon, 06 Nov 2017 10:11:04 GMT

Hi,

thanks for you reply.

I tried tFileInputFullRow. But then the column only has one element. When I want to print it, it still prints 'null'.

When I use tLogRow it works fine.

Do you have any idea what my component does wrong?

Re: Read data from data input flow

Anonymous — Tue, 07 Nov 2017 03:50:14 GMT

Hi,

What does your custom component look like? Have you already shared your custom component on talend exchange portal?

Best regards

Sabrina

Re: Read data from data input flow

Anonymous — Tue, 07 Nov 2017 09:16:52 GMT

Hi,

I have not published the component as it doesn't work for the moment. In attachment you can find the .xml and begin files.

tLearnInput_java.xml
tLearnInput.zip

Re: Read data from data input flow

Anonymous — Tue, 07 Nov 2017 09:54:27 GMT

Hi,

Somehow now it works. I had a look at the tFileOutputPDF component and changed some lines. I don't know what the mistake was but ich works

But I still have a question:

If I put all the code to the begin.javajet file again I just get 'null'.

Why do I have to read for input in the main file?

tLearnInput.zip