1    /* 
2    * A Java program to perform some basic operations on a list of Strings 
3    * using Java Streams 
4    * 
5    * By: Hunter Gersitz | SUNY Oswego Fall 2019 
6    * 
7    * */
8    
9    package arraylists;
10   
11   import java.awt.*;
12   import java.util.ArrayList;
13   import java.util.List;
14   import java.util.stream.Collectors;
15   
16   public class StreamArrayListProcessing {
17   
18       public static void main(String[] args) {
19   
20           // POINT A
21           List<String> names = new ArrayList<>();
22           names.add("Holiday, Billie");
23           names.add("Claudel, Camille");
24           names.add("Picasso, Pablo");
25           names.add("Gallen-Kallela, Akseli");
26           names.add("Zotto, Osvaldo");
27   
28           // POINT B
29           List<String> firstNamesList = names.stream()
30                   .map(n -> firstName(n))
31                   .collect(Collectors.toList());
32           System.out.println("First names: ");
33           for (String firstName : firstNamesList){
34               System.out.println(firstName + " ");
35           }
36   
37   
38           // POINT C
39   
40           String firstNames = names.stream()
41                   .map(n -> firstName(n))
42                   .collect(Collectors.joining(", "));
43           System.out.println("First names: " + firstNames);
44   
45           // POINT D
46   
47           String lastNames = names.stream()
48                   .map(m -> lastName(m))
49                   .collect(Collectors.joining(", "));
50           System.out.println("Last names: " + lastNames);
51   
52           // POINT E
53   
54           String upperCaseFirstNames = names.stream()
55                   .map(n -> firstName(n))
56                   .map(n -> n.toUpperCase())
57                   .collect(Collectors.joining(", "));
58           System.out.println("Uppercase first names: " + upperCaseFirstNames);
59   
60           // POINT F
61   
62           String hyphenatedLastNames = names.stream()
63                   .map(n -> lastName(n))
64                   .filter(n -> n.contains("-"))
65                   .collect(Collectors.joining(", "));
66           System.out.println("Last names hyphenated: " + hyphenatedLastNames);
67   
68   
69           // POINT G
70   
71           int totalLength = names.stream()
72                   .map(n -> n.length())
73                   .reduce(0, (n1, n2) -> n1 + n2);
74           System.out.println("Total length: " + totalLength);
75   
76           // POINT H
77           int firstNamesLength = names.stream()
78                   .map(n -> firstName(n).length())
79                   .reduce(0, (n1, n2) -> n1 + n2);
80           System.out.println("Total length of first names: " + firstNamesLength);
81   
82   
83           // POINT I
84           int productTotalLength = names.stream()
85                   .map(n -> n.length())
86                   .reduce(1, (n1, n2) -> n1*n2);
87           System.out.println("Product of names in list: " + productTotalLength);
88   
89   
90   
91       }
92   
93       private static String firstName(String directoryStyleName) {
94           int spaceLoc = directoryStyleName.indexOf(" ");
95           return directoryStyleName.substring(spaceLoc + 1);
96       }
97   
98       private static String lastName(String directoryStyleName) {
99           int lastNameComaLoc = directoryStyleName.indexOf(",");
100          return directoryStyleName.substring(0, lastNameComaLoc);
101      }
102  
103  }
104