How to print list<> result from database

Question

i have code

        Customer customerWithId10 = customerDao.getCustomerById(1);

        List<Customer> customerFirst10Rows = customerDao.getCustomers(0, 10);
       for(int i=0;i<customerFirst10Rows.size();i++){
           System.out.println(customerFirst10Rows.get(i));
       }

But i get result like this

co.id.ipb.ilkom.training.model.Customer@41140b9 co.id.ipb.ilkom.training.model.Customer@41140b9 co.id.ipb.ilkom.training.model.Customer@41140b9

How to print and get the data?

here my CustomerDao

public class CustomerDaoMysql implements CustomerDao{
 private static final String SELECT_PAGING_QUERY
        = "SELECT * FROM CUSTOMER LIMIT ?,?";
  private static final String SELECT_BY_ID_QUERY
        = "SELECT * FROM CUSTOMER WHERE ID=?";
 private Connection connection;

public CustomerDaoMysql(Connection connection) {
    this.connection = connection;
}
@Override
   public List<Customer> getCustomers(Integer indexStart, Integer numOfRows) {
    try {
        PreparedStatement selectWithPagingPreparedStatement
                = connection.prepareStatement(SELECT_PAGING_QUERY);
        selectWithPagingPreparedStatement.setInt(1, indexStart);
        selectWithPagingPreparedStatement.setInt(2, numOfRows);
        ResultSet customerResultSet = selectWithPagingPreparedStatement.executeQuery();
        List<Customer> customers = new ArrayList<>();
        while (customerResultSet.next()) {
            customers.add(extractCustomerFromResultSet(customerResultSet));
        }
        return customers;
    } catch (SQLException ex) {
        Logger.getLogger(CustomerDaoMysql.class.getName()).log(Level.SEVERE, null, ex);
    }
    return Collections.emptyList();
}

public Customer extractCustomerFromResultSet(ResultSet customerResultSet) throws SQLException {
    Customer customer = new Customer();
    customer.setId(customerResultSet.getInt("ID"));
    customer.setName(customerResultSet.getString("NAME"));
    customer.setEmail(customerResultSet.getString("EMAIL"));
    customer.setAddress(customerResultSet.getString("ADDRESS"));
    Date birthDate = customerResultSet.getDate("BIRTH_DATE");
    customer.setBirthDate(new java.util.Date(birthDate.getTime()));
    return customer;

}

Define a `toString` method for `Customer`. – Makoto Apr 18 '16 at 05:17 — Makoto, Apr 18 '16 at 05:17
what all elements of customer you want to print? – SpringLearner Apr 18 '16 at 05:20 — SpringLearner, Apr 18 '16 at 05:20
i want to get name and id from the data what should i do – Rijen Juni Apr 18 '16 at 05:31 — Rijen Juni, Apr 18 '16 at 05:31

Yati Sawhney · Answer 1 · 2017-08-10T17:15:37.660

0

List<Customer> customerFirst10Rows = customerDao.getCustomers(0, 10);

This simply means you are going to receive a list of Customers may be 10 in your case.

In that list each element is an object of type Customer and Therefore, System.out.println(customerFirst10Rows.get(i)); prints the contents of the toString() method

If you have defined getters for the fields used in your Customer class you could call them here like you have a field "name" which represents the customer name

Then you should use System.out.println(customerFirst10Rows.get(i).getName()) to get the value Simillarly for all the fields

Else you could overide the toString() method for you Customer class. The way you want to print you values

edited Aug 10 '17 at 17:15

answered Apr 18 '16 at 05:26

Yati Sawhney

1,372
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thanks Sawhney,, with that program actually i only get 10 data if i want to get all data from table what should i do.? – Rijen Juni Apr 18 '16 at 07:01
post your getCustomer() method code here or the actual method where you are trying to access the data base that includes the SELECT query – Yati Sawhney Apr 18 '16 at 07:28
i was post the customerDao code in my questions – Rijen Juni Apr 19 '16 at 09:23

score 0 · Answer 2 · answered Apr 18 '16 at 06:51

Just override toString() method in your Customer data class. By this way you can pretty print your Customer object in every out operation. Related code is like below:

@Override
public String toString() {
    return getName() + " , "+getSurname() + " , "+getAdress();
}

After you override toString() method, your outputs will be like that:

Lionel , Messi , Barcelona
Cristiano , Ronaldo , Madrid

How to print list<> result from database

2 Answers2