1    
2    package arraylistplay.arraylists;
3    
4    import java.util.ArrayList;
5    import java.util.List;
6    import java.util.stream.Collectors;
7    
8    public class StreamArrayListProcessing {
9        public static void main(String[] arg) {
10   
11           //Point A
12           List<String> names = new ArrayList<>();
13           names.add("Holiday, Billie");
14           names.add("Claudel, Camille");
15           names.add("Picasso, Pablo");
16           names.add("Gallen-kallela, Akseli");
17           names.add("Zotto, Osvaldo");
18   
19   
20           //Point B
21           List<String> firstNamesList = names.stream()
22                   .map(n -> firstName(n))
23                   .collect(Collectors.toList());
24           System.out.println("First names: ");
25           for (String firstName : firstNamesList){
26               System.out.println(firstName + " ");
27           }System.out.println();
28   
29           //Point C
30           String firstNames = names.stream()
31                   .map(n -> firstName(n))
32                   .collect(Collectors.joining(", "));
33           System.out.println("First names: " + firstNames);
34           System.out.println();
35   
36           //Point D
37           List<String> lastNamesList = names.stream()
38                   .map(n -> lastName(n))
39                   .collect(Collectors.toList());
40           System.out.println("Last names: ");
41           for (String lastName : lastNamesList){
42               System.out.println(lastName + " ");
43           }System.out.println();
44   
45           String lastNames = names.stream()
46                   .map(n -> lastName(n))
47                   .collect(Collectors.joining(", "));
48           System.out.println("Last names: " + lastNames);
49   
50           //Point E
51           String upperCaseFirstNames = names.stream()
52                   .map(n -> firstName(n))
53                   .map(n -> n.toUpperCase())
54                   .collect(Collectors.joining(", "));
55           System.out.println("Uppercase first names: " + upperCaseFirstNames);
56   
57           //Point F
58           String hyphenatedLastNames = names.stream()
59                   .map(n -> lastName(n))
60                   .filter(n -> n.contains("-"))
61                   .collect(Collectors.joining(", "));
62           System.out.println("hyphenateds names: " + hyphenatedLastNames);
63   
64           //Point G
65           int totalLength = names.stream()
66                   .map(n -> n.length())
67                   .reduce(0, (n1, n2) -> n1 + n2);
68           System.out.println("Total length: " + totalLength);
69   
70           //Point H
71           int totalfirstLength = names.stream()
72                   .map(n -> n.length())
73                   .reduce(0, (n1, n2) -> n1 + n2);
74           System.out.println("first name Total length: " + totalfirstLength);
75   
76           //Point I
77           double totalProduct= names.stream()
78                   .map(n-> n.length())
79                   .reduce(1,(n1,n2)-> n1 * n2);
80           System.out.println("Total Product:"+ totalProduct);
81       }
82   
83       private static String firstName(String directoryStyleName) {
84           int commaPosition = directoryStyleName.indexOf(",");
85           return directoryStyleName.substring(commaPosition + 2);
86       }
87       private static String lastName(String directoryStyleName) {
88           int commaPosition = directoryStyleName.indexOf(",");
89           return directoryStyleName.substring(0, commaPosition);
90       }
91   }
92   
93