Counting rows and saving the result in array (map) in Talend Open Studio

Question

I have a job in Talend Open Studio. It supposed to be counting filtered input rows and storing it in adequate variable. The input file is csv. Later I use tMap to take only rows from selected day:

And then I'm stuck. I just need an array (or array map?) with 24hrs (values 0-23) and increment them everytime the time matches.

How do I implement an array in Talend which I can use inside tMap (I can use third party library)? Or is there some other way of doing that? I want to output those variables values to csv.

Answer 1

I would suggest you to write a user defined function and call it in tmap.. something like below

public static String loop_cntr(Int cntr){

String ARR = "" ;
for(int i=0;i<cntr;i++){
<your logic to build the array>
ARR = ARR + cntr (something like this)
}
return ARR
)

now you can use this function in tMap like loop_cntr(20)

I am assuming that you know how to write custom function Code-->Routines. Please let me know how it goes.

Answer 2

If I understand your description correctly, you want to sum all columns which do have a specific hour value. You could use a combination of tMap and tAggregateRow .

First, you would define a tMap with 24 columns on the right side. Row for row, this would only be filled if a condition is met, eg

TalendDate.getPartOfDate("HOUR",row1.Time_Stamp) == 0

into columnHour0 ,

TalendDate.getPartOfDate("HOUR",row1.Time_Stamp) == 1

into columnHour1 etc. up to columnHour23 .

Now connect the tAggregateRow and sum every hour column in the "Operations" box. This should result in only one row with all the counted hour entries.

Answer 3

您知道tflowmeter和tflowmetercatcher的组件吗？