Testing.java

package com.insightfullogic.java8.examples.chapter7;

import com.insightfullogic.java8.examples.chapter1.Album;
import com.insightfullogic.java8.examples.chapter1.Artist;

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.logging.Logger;
import java.util.stream.Collectors;

public class Testing {

    private static final Logger logger = Logger.getLogger("Testing");

    // BEGIN to_uppercase
public static List<String> allToUpperCase(List<String> words) {
    return words.stream()
                .map(string -> string.toUpperCase())
                .collect(Collectors.<String>toList());
}
    // END to_uppercase

    // BEGIN firstToUpperCase_lambda
public static List<String> elementFirstToUpperCaseLambdas(List<String> words) {
    return words.stream()
            .map(value -> { // <1>
                char firstChar = Character.toUpperCase(value.charAt(0));
                return firstChar + value.substring(1);
            })
            .collect(Collectors.<String>toList());
}
    // END firstToUpperCase_lambda

    // BEGIN firstToUpperCase_reference
public static List<String> elementFirstToUppercase(List<String> words) {
    return words.stream()
                .map(Testing::firstToUppercase)
                .collect(Collectors.<String>toList());
}

public static String firstToUppercase(String value) { // <1>
    char firstChar = Character.toUpperCase(value.charAt(0));
    return firstChar + value.substring(1);
}
    // END firstToUpperCase_reference

    public static Set<String> imperativeNationalityReport(Album album) {
        // BEGIN imperative_nationality_report
Set<String> nationalities = new HashSet<>();
for (Artist artist : album.getMusicianList()) {
    if (artist.getName().startsWith("The")) {
        String nationality = artist.getNationality();
        System.out.println("Found nationality: " + nationality);
        nationalities.add(nationality);
    }
}
return nationalities;
        // END imperative_nationality_report
    }

    public static Set<String> forEachLoggingFailure(Album album) {
        // BEGIN foreach_logging_nationality_report
album.getMusicians()
     .filter(artist -> artist.getName().startsWith("The"))
     .map(artist -> artist.getNationality())
     .forEach(nationality -> System.out.println("Found: " + nationality));

Set<String> nationalities
    = album.getMusicians()
           .filter(artist -> artist.getName().startsWith("The"))
           .map(artist -> artist.getNationality())
           .collect(Collectors.<String>toSet());
        // END foreach_logging_nationality_report
        return nationalities;
    }

    public static Set<String> nationalityReportUsingPeek(Album album) {
        // BEGIN peek_nationality_report
Set<String> nationalities
    = album.getMusicians()
           .filter(artist -> artist.getName().startsWith("The"))
           .map(artist -> artist.getNationality())
           .peek(nation -> System.out.println("Found nationality: " + nation))
           .collect(Collectors.<String>toSet());
        // END peek_nationality_report
        return nationalities;
    }

}