Many a times, you are required to convert flat file structures to deeply nested structures like IDocs. Standard File Content Conversion allows you to convert the incoming file to flat XML structures only i.e. only one level of nesting is possible. Converting incoming file to deeply nested structures would require use of either custom developed adapter modules or third-party conversion agents.

This article provides a workaround to accomplish the same thing by using only the graphical mapping. William had a similar requirement, and we came up with a generic solution which is described below.

Lets say we have an incoming flat file with structure as described below –

Node1 – Occurs 0..1
Node2 – Occurs 0..unbounded
Node3 – Occurs 0..unbounded
Node4 – Occurs 0..unbounded

And the target structure is as shown below –

Node1 – Occurs 0..1
Node2 – Occurs 0..unbounded
Node3 – Occurs 0..unbounded and repeats under the preceding Node2
Node4 – Occurs 0..unbounded and repeats under the preceding Node3

Due to limitation of the standard File adapter, it is not possible to directly convert the incoming file to the deeply nested target structure. Hence we will use a two step message mapping to attain the required result.

First, we will use file content conversion as shown to covert the incoming file to flat XML structure as supported by the adapter. Click the image on the right to see an enlarged view. We will then use two-step message mapping to convert the flat XML to a nested XML. Figure below shows the flat XML structure generated by the file adapter using file content conversion.

Our aim is to convert the above flat structure to a nested shown below –

Note that there is no common element between parent and child nodes (e.g. Node2 and Node3, or Node3 and Node4) which we could use to determine corresponding parent node for each child node.

Courtesy of http://www.riyaz.net. To read the entire article click here.