ClassCastException

[aldosilva]

Hi guys, I'm a new developer in spring batch and when I execute the test in my application I get an exception. java.lang.ClassCastException: java.util.ArrayList the error appears when I terminate the execute the ItemReader and pass to the ItemWrite of package import org.springframework.batch.item.ItemWriter;

my class Reader:

public class CategoriaTarifariaItemReader implements ItemReader<List<CategoriaTarifaria>>{

public List<CategoriaTarifaria> read() throws Exception,
UnexpectedInputException, ParseException {

List<CategoriaTarifaria> categoriaTarifas = obterDadosCategoriaTarifa(3);

return categoriaTarifas;
}
}



Thank's for your attention!!

[DHGarrette]

What type is your ItemWriter expecting? The ItemWriter must always take a List of whatever the ItemReader is returning. So, in that case, your ItemWriter should expect an item of type List<? extends List< CategoriaTarifaria>>

[aldosilva]

Yeap, you are right, my ItemWrite is:

public class CategoriaTarifariaItemWrite implements ItemWriter<List<CategoriaTarifaria>>{

public void write(List<? extends List<CategoriaTarifaria>> items)
throws Exception {

List<CategoriaTarifaria> categoriaTarifas = (List<CategoriaTarifaria>)items;
for (CategoriaTarifaria categoriaTarifaria : categoriaTarifas) {

try{

categoriaTarifariaFacade.gravarDadosCategoriaTarif a(categoriaTarifaria);

}catch(CategoriaTarifariaException ex){
logger.error("Erro to save CategoriaTarifaria.", ex);
throw ex;
}

}

}


But when I debug my application the ItemRead not reach the ItemWrite. I don't know what is happening.

Thank's for reply.

[DHGarrette]

The statement "(List<CategoriaTarifaria>)items" will never work. "items" is of type "List<? extends List<CategoriaTarifaria>> items".

Also, please use CODE tags when posting code.

[aldosilva]

Ok. Thank's. I solved my problem reading item by item instand of reading a list, because when I read a list the container put the list inside another list and when I wrote I couldn't converter the list to my type.

[aldosilva]

The class ItemReader:

public class CategoriaTarifariaItemReader implements ItemReader<CategoriaTarifaria>
public CategoriaTarifaria read() throws Exception,
			UnexpectedInputException, ParseException {
		CategoriaTarifaria categoriaTarifaria = null;
		if(categoriaTarifas == null){
			categoriaTarifas = obterDadosCategoriaTarifa(3);
		}
		
		if(!categoriaTarifas.isEmpty()){
			categoriaTarifaria = categoriaTarifas.remove(0);
		}
		
		return categoriaTarifaria;
	}
}