StreamArrayListProcessing.java
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package arraylists;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
public class StreamArrayListProcessing {
public static void main(String[] args){
List<String> names = new ArrayList<>();
names.add("Holiday, Billie");
names.add("Claudel, Camille");
names.add("Picasso, Pablo");
names.add("Gallen-Kallela, Akseli");
names.add("Zotto, Osvaldo");
names.add("Schukraft, Sean");
names.add("Ross, Bob");
//First names
List<String> firstNamesList = names.stream()
.map(n -> firstName(n))
.collect(Collectors.toList());
System.out.print("First names: ");
for (String firstName : firstNamesList){
System.out.print(firstName + " ");
}
System.out.println();
String firstNames = names.stream()
.map(n -> firstName(n))
.collect(Collectors.joining(", "));
System.out.println("First names: " + firstNames);
//Last names
List<String> lastNamesList = names.stream()
.map(n -> lastName(n))
.collect(Collectors.toList());
System.out.print("Last names: ");
for (String lastName : lastNamesList){
System.out.print(lastName + " ");
}
System.out.println();
String lastNames = names.stream()
.map(n -> lastName(n))
.collect(Collectors.joining(", "));
System.out.println("Last names: " + lastNames);
//First names to uppercase
String upperCaseFirstNames = names.stream()
.map(n -> firstName(n))
.map(n -> n.toUpperCase())
.collect(Collectors.joining(", "));
System.out.println("Uppercase first names: " + upperCaseFirstNames);
//Names with hyphens
String hyphenatedLastNames = names.stream()
.map(n -> lastName(n))
.filter(n -> n.contains("-"))
.collect(Collectors.joining(", "));
System.out.println("Hyphenated last names: " + hyphenatedLastNames);
//Total name length
int totalLength = names.stream()
.map(n -> n.length())
.reduce(0, (n1, n2) -> n1 + n2);
System.out.println("Total length: " + totalLength);
//Total first name length
int totalFirstLength = firstNamesList.stream()
.map(n -> n.length())
.reduce(0, (n1, n2) -> n1 + n2);
System.out.println("Total first name length: " + totalFirstLength);
//Product total of names
int totalProductLength = names.stream()
.map(n -> n.length())
.reduce(1, (n1, n2) -> n1 * n2);
System.out.println("Total product length: " + totalProductLength);
}
public static int productNameLength(List<String> names){
int totalLength = 1;
for (String name : names){
totalLength = totalLength * name.length();
}
return totalLength;
}
private static String firstName(String directoryStyleName) {
int commaPosition = directoryStyleName.indexOf(",");
return directoryStyleName.substring((commaPosition + 2), (directoryStyleName.length()));
}
private static String lastName(String directoryStyleName) {
int commaPosition = directoryStyleName.indexOf(",");
return directoryStyleName.substring(0, commaPosition);
}
}