Nsryjdtyk

I have following Java class and list as:-

   class Person{

        String name;

        int age;

        Address address;



    }



    class Address{

        String street;

        String post_code;

        String city;

        String country;

    }



    List<Person> personList = new ArrayList<>();

I would like to generate s CSV file from the list. I could easily do it if there were not compound class hariacy. Can you please suggest how can I do it? I tried opencsv and filed to do it. Opencsv works for noncompound class. I might have done something wrong. So code example will be helpful.

CSV= "Comma Separated Values".
You can create by yourself a csv file. You could write in the file values separated with a comma (or semi-colon). those values are cells of one row. a row is over wenn you write a line separator.

hier is a simple and basic sample of how to write rows in a csv format:

public static final char CSV_SEPARATOR = ';'; // it could be a comma or a semi colon



try (BufferedWriter writer = new BufferedWriter(new FileWriter("my_file.csv"))) {

    personList.forEach(person -> {

        writer.append(person.getName()).append(CSV_SEPARATOR)

              .append(person.getAge()).append(CSV_SEPARATOR)

              .append(persone.getAddress().getStreet()).append(CSV_SEPARATOR)

              .append(persone.getAddress().getpostCode()).append(CSV_SEPARATOR)

              .append(persone.getAddress().getCity()).append(CSV_SEPARATOR)

              .append(persone.getAddress().getCountry()).append(System.lineSeparator());

    });

} catch (IOException ex) {

    ex.printStackTrace();

}

but for your case, I would define an interface CsvPrintable

public interface CsvPrintable {

   String printCsv();

}

then, classes Person and Address implements this interface

class Person implements CsvPrintable {



String name;

int age;

Address address;



@Override

printCsv() {

   return StringBuilder().append(name).append(CSV_SEPARATOR)

                         .append(age).append(CSV_SEPARATOR)

                         .append(address.printCsv()).toString();

   }

}

You should do the same thing with Address.

then we can improve the first code block:

personList.forEach(person -> {

        writer.append(person.printCsv()).append((System.lineSeparator());

    });

Define a new class, for example PersonWithAddress that includes all fields from Person and Address. Transform your Person List into a PersonWithAddress List. Now, you can give openCSV what it wants.