Simple UDF for Concatenate multiple input fields

[Former Member]

I have a requirement to Concatenate More then 20 fields in message mapping .

Difficult to use standard Concatenate function in such scenario .

Can you please suggest me how to write simple Concatenate function in PI (Grahical mapping)

I tried by creating UDF with Execution Type as Single Values ( for example var1 ,var2, var3)

// Java Code

String JainOutput ;

JainOutput = Var1 + Var2 + Var3

But It is throwing error. Can any one provide me exact logic how to write for concatenate multiple values

Jain