Me puede ayudar en java

[WArlox]

Tengo un problema no se si es en la clases. se lo presnto
public ArrayList getCed(String cedula) {
String query ="SELECT count(*) as cont, clave, sum(to_number(monto, '999999999.99')) as total FROM (SELECT count(*) as con, (substring(estructura,1,1)) as codigoregion,tipotrabajador,trabajadorextra.cedula ,estructura,zona, sum(to_number(monto, '999999999.99')) as monto,ano,mes ,clave from trabajadorextra where (to_number(clave, '999')<200 or to_number(clave, '999')>500) and clave!=992 and clave!=545 and clave!=671 and clave!=549 and clave!=525 and clave!=626 and clave!=509 and trabajadorextra.cedula='"+cedula+"' group by ano, mes,estructura,zona,trabajadorextra.cedula,codigor egion,tipotrabajador ,clave )as pro group by clave order by clave ";
return this.getCed(query);
}



protected ArrayList getCedRecibos(String query) {
try {
ResultSet rs = stmt.executeQuery("query");
ArrayList lista = new ArrayList();
while (rs.next()) {
lista.add(new Recibo (rs.getString("cedula"),rs.getString("Clave"),rs.g etString("Total")));
}

ahora lo llamo:
public ArrayList getCed(String cedula) {
String query ="SELECT count(*) as cont, clave, sum(to_number(monto, '999999999.99')) as total FROM (SELECT count(*) as con, (substring(estructura,1,1)) as codigoregion,tipotrabajador,trabajadorextra.cedula ,estructura,zona, sum(to_number(monto, '999999999.99')) as monto,ano,mes ,clave from trabajadorextra where (to_number(clave, '999')<200 or to_number(clave, '999')>500) and clave!=992 and clave!=545 and clave!=671 and clave!=549 and clave!=525 and clave!=626 and clave!=509 and trabajadorextra.cedula='"+cedula+"' group by ano, mes,estructura,zona,trabajadorextra.cedula,codigor egion,tipotrabajador ,clave )as pro group by clave order by clave ";
return this.getCed(query);
}



protected ArrayList getCedRecibos(String query) {
try {
ResultSet rs = stmt.executeQuery("query");
ArrayList lista = new ArrayList();
while (rs.next()) {
lista.add(new Recibo (rs.getString("cedula"),rs.getString("Clave"),rs.g etString("Total")));
}

Me da este error

StandardWrapperValve[debugjsp]: Servlet.service() para servlet debugjsp lanzó excepción

java.lang.OutOfMemoryError

java.lang.OutOfMemoryError

por favor necesito que me ayude. se lo agradezco.