java_upgrade/src/main/java/UseProducts.java at main · ps4/java_upgrade · GitHub

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import java.util.Arrays;

import java.util.List;

import java.util.logging.Logger;

import java.util.stream.Collectors;

public class UseProducts {

private static final Logger logger = Logger.getLogger(UseProducts.class.getName());

public static void main(String[] args) {

List<Product> products = Arrays.asList(new Product("football", 10),

new Product("basketball", 12), new Product("baseball", 5));

List<String> names = products.stream() // Stream<Product>

.map(Product::getName) // Stream<String>

// .peek(System.out::println)

.collect(Collectors.toList());

// complex string arg always gets formed!

// Arguments to methods always get evaluated

logger.info("Product not found; available products are: " + names);

// supplier.get() only invoked if loggable

logger.info(() -> "Product not found; available products are: " + names);

}

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