Using XML with Legacy Business Applications

Validation of the Input Document

The most obvious enhancement we can make to this program is to validate the input document before we try to process it. As I previously pointed out, we can run into unexpected output, no output, or abnormal termination if the input document doesn't conform to the expected structure. There are two ways we can handle this.

The first way is to add additional code to the program in several places to deal with unexpected conditions. For example, in the main method we would check to see that there was at least one Row Node in the NodeList. We would want to do the same thing when checking for ColumnXX children of the Row Nodes in the CSVRowWriter write method. In addition, we would want to verify that the Row Node's ...