Univocity - parse each TSV file row to different Type of class object - univocity

Question

I have a tsv file which has fixed rows but each row is mapped to different Java Class.
For example.
recordType recordValue1
recordType recordValue1 recordValue2
for First row I have follofing class:
public class FirstRow implements ItsvRecord {
#Parsed(index = 0)
private String recordType;
#Parsed(index = 1)
private String recordValue1;
public FirstRow() {
}
}
and for second row I have:
public class SecondRow implements ItsvRecord {
#Parsed(index = 0)
private String recordType;
#Parsed(index = 1)
private String recordValue1;
public SecondRow() {
}
}
I want to parse the TSV file directly to the respective objects but I am falling short of ideas.

Answer 1

Use an InputValueSwitch. This will match a value in a particular column of each row to determine what RowProcessor to use. Example:
Create two (or more) processors for each type of record you need to process:
final BeanListProcessor<FirstRow> firstProcessor = new BeanListProcessor<FirstRow>(FirstRow.class);
final BeanListProcessor<SecondRow> secondProcessor = new BeanListProcessor<SecondRow>(SecondRow.class);
Create an InputValueSwitch:
//0 means that the first column of each row has a value that
//identifies what is the type of record you are dealing with
InputValueSwitch valueSwitch = new InputValueSwitch(0);
//assigns the first processor to rows whose first column contain the 'firstRowType' value
valueSwitch.addSwitchForValue("firstRowType", firstProcessor);
//assigns the second processor to rows whose first column contain the 'secondRowType' value
valueSwitch.addSwitchForValue("secondRowType", secondProcessor);
Parse as usual:
TsvParserSettings settings = new TsvParserSettings(); //configure...
// your row processor is the switch
settings.setProcessor(valueSwitch);
TsvParser parser = new TsvParser(settings);
Reader input = new StringReader(""+
"firstRowType\trecordValue1\n" +
"secondRowType\trecordValue1\trecordValue2");
parser.parse(input);
Get the parsed objects from your processors:
List<FirstRow> firstTypeObjects = firstProcessor.getBeans();
List<SecondRow> secondTypeObjects = secondProcessor.getBeans();
The output will be*:
[FirstRow{recordType='firstRowType', recordValue1='recordValue1'}]
[SecondRow{recordType='secondRowType', recordValue1='recordValue1', recordValue2='recordValue2'}]
Assuming you have a sane toString() implemented in your classes
If you want to manage associations among the objects that are parsed:
If your FirstRow should contain the elements parsed for records of type SecondRow, simply override the rowProcessorSwitched method:
InputValueSwitch valueSwitch = new InputValueSwitch(0) {
#Override
public void rowProcessorSwitched(RowProcessor from, RowProcessor to) {
if (from == secondProcessor) {
List<FirstRow> firstRows = firstProcessor.getBeans();
FirstRow mostRecentRow = firstRows.get(firstRows.size() - 1);
mostRecentRow.addRowsOfOtherType(secondProcessor.getBeans());
secondProcessor.getBeans().clear();
}
}
};
The above assumes your FirstRow class has a addRowsOfOtherType method that takes a list of SecondRow as parameter.
And that's it!
You can even mix and match other types of RowProcessor. There's another example here that demonstrates this.
Hope this helps.