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