Troubleshooting adapter module JCo RFC callsPosted: February 2, 2014
From my blog on SCN – http://scn.sap.com/community/pi-and-soa-middleware/blog/2013/12/23/troubleshooting-adapter-module-jco-rfc-calls
Many a times we have adapter modules ( AM ) which in turn do a RFC call to ABAP stack of the XI system to retrieve information. This can be handy to make a generic AM that can be plugged in for multiple interfaces.
As an example, if we already have a text file with idoc data in plain text format, the adapter module can be used to convert this data into idoc format. The ABAP stack FM can be created to inquire idoc metadata information in IDX2 and use it to create the idoc structure.
The different steps are as follows:
1.This step shows the data being processed in the module chain. It’s represented in hex format for the message. So, if we have a text file with content “hello” – the message will be “68 65 6c 6c 6f”.
2.The message is entering the module chain. It can be after reading the file for a sender FTP adapter if this is the first module or after another module call e.g. for code page conversion.
3.As part of the adapter module processing, a RFC call is made using Java Connector ( JCo ) with the message and other parameters. These will be adapter module parameters.
4.The returned message is idoc data in hex format of the XML stream.
5.The message is leaving the adapter module.
6.The data is in hex for the idoc. To make it simple, if the idoc data is “<hello>” the message here is “3c 68 65 6c 6c 6f 3e”.
In the above diagram, the module parameters are sent to the RFC function module in text format though the message data will be hex.
With all the above theoretical knowledge, let’s create a simple Java program that can aid in troubleshooting.Pre-requisite Libraries to be added to our project:
1. Google Guava :
Get it from here – http://code.google.com/p/guava-libraries/
2. JCO libs
Get it from service marketplace.
3. Create a jar with the property file: I’ve provided a sample property file. It has the details to make us connect to the host, authenticate
Files to be created:
1. Props.properties : to store connection / authentication details so that it’s easy to change the target instead of hardcoding the values in the program.
2. PropHelper.java : Helper class to read properties file.
3. simulateRFCBean: This is the main class – it’s used for reading the file and making the JCo RFC call.
The steps will be:
1.Check the function module for parameters of type IMPORT (or ask your friendly ABAP colleague about the function module.)
This FM requires two parameters:
SOURCE (the message sent as hexadecimal stream).
SNDPRN (This is a just normal text)
The names won’t have to necessarily match as within the module, we map parameter ‘partner’ to ‘SNDPRN’ for the RFC call.
2.Map the data types to Java using the table mentioned above.
Looking at the function module and the data mapping, we’ll need to
a) Convert the file contents to a hexadecimal string ( byte array in Java )
b) Send the sending system as a string ( String in Java )
3.With the above information, it’s straight forward to create the Java program.
a)Read the JCO properties – PropHelper.java is a helper class to help read these properties instead of hardcoding in the program.
b)Read the file to be checked and convert to byte array.
byte fileData = Files.toByteArray(new File(“C://temp//bad3.txt”));
– Do the necessary JCO Set up, set the parameters to be supplied for the RFC call
and finally, make the call.
Now with the set up done, we’re able to replicate the error scenario.
The issue on the communication channel log indicated.
Using this program, we’re able to replicate the failure.
For debugging on ABAP, an external break-point needs to be set up in the called function module.
Some of the error scenarios we encountered:
- Bad data – new line appearing in the message.
- IDX2 configuration missing for the unique message combination – existing for the basic type and an extension.
However, once we’re able to simulate the failure and debug the issue, finding the resolution is much easier.
Sourcde code link : https://github.com/viksingh/SimulateRFCCalls