Strategy . ,
Factory Factory .
. ,
.
interface Validator {
// since it is not clear what are the attributes that matter for a record,
// this takes an instance of Record.
// Modify to accept relevant attribures of Record
public boolean validate (Record r);
}
class ConcreteValidator implements Validator {
// implements a validation logic
}
// implements Comparable so that it can be used in rules that compare Records
abstract class Record implements Comparable<Record> {
protected Validator v;
abstract void setValidator(Validator v);
public boolean isValid() {
return v.validate(this);
}
}
class ConcreteRecord extends Record {
// alternatively accept a Validaor during the construction itself
// by providing a constructor that accepts a type of Validator
// i.e. ConcreteRecord(Validator v) ...
void setValidator(Validator v) {
this.v = v;
}
// implementation of method from Comparable Interface
public int compareTo(final Record o) {... }
}
public class Test {
public static void main(String[] args) {
// Store the read in Records in a List (allows duplicates)
List<Record> recordList = new ArrayList<Record>();
// this is simplistic. Your Record creation mode might be
// more complex, And you can use a Factory Method
// (or Simple Factory) for creation of ConcreteRecord
Record r = new ConcreteRecord();
r.setValidtor(new ConcretedValidator());
if (r.isValid()) {
// store only valid records
recordList.add(r);
}
// do further processing of Records stored in recordList
}
}