java_upgrade/src/main/java/optional/ProductDAO.java at master · rlwing/java_upgrade · GitHub

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package optional;

import java.util.Map;

import java.util.Optional;

import static java.util.Map.entry;

import static java.util.Map.ofEntries;

//Also very cool!

public class ProductDAO {

private static Map<Integer, Product> products =

ofEntries(entry(1, new Product(1, "Football", 12.99)),

entry(2, new Product(2, "Basketball", 15.99)),

entry(3, new Product(3, "Baseball", 5.99)));

public Optional<Product> findById(Integer id) {

return Optional.ofNullable(products.get(id));

}

public Product getProductById(Integer id) {

Optional<Product> optional = findById(id);

// Create default product only if no product with that id

return optional.orElseGet(() -> new Product(999, "No name", 0.00));

}

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