1    package arraylists;
2    import java.util.ArrayList;
3    import java.util.List;
4    import java.util.stream.Collectors;
5    public class StreamArrayListProcessing {
6        public static void main(String[] args){
7            // POINT A: Add some strings which represent names to an ArrayList.
8            List<String> names = new ArrayList<>();
9            names.add("Holiday, Billie");
10           names.add("Claudel, Camille");
11           names.add("Picasso, Pablo");
12           names.add("Gallen-Kallela, Akseli");
13           names.add("Zotto, Osvaldo");
14           names.add("VerHeecke, Zachary");
15   
16   
17           // POINT B: Use map and the toList collector to create an ArrayList of just
18           //          the first names of the names ArrayList. Use a for loop to print
19           //          out the names, separated by spaces.
20           List<String> firstNamesList = names.stream()
21                   .map(n -> firstName(n))
22                   .collect(Collectors.toList());
23           System.out.print("First names: ");
24           for (String firstName : firstNamesList)
25           {
26               System.out.print(firstName + " ");
27           }
28   
29       System.out.println();
30   
31           // POINT C: Use map and the joining collector to create a String of just
32           //          the first names of the names ArrayList with each name separated
33           //          by a comma. Print it.
34           String firstNames = names.stream()
35                   .map(n -> firstName(n))
36                   .collect(Collectors.joining(" "));
37           System.out.println("First names: " + firstNames);
38           // POINT D: By analogy from point C, print a comma-separated list of the
39           //          last names in the names ArrayList.
40           String lastNames = names.stream()
41                   .map(n -> lastName(n))
42                   .collect(Collectors.joining(" "));
43           System.out.println("Last names: " + lastNames);
44           // POINT E: Print a comma-separated list of all uppercase first names
45           //          from the list of names in the names ArrayList.
46           String upperCaseFirstNames = names.stream()
47                   .map(n -> firstName(n))
48                   .map(n -> n.toUpperCase())
49                   .collect(Collectors.joining(" "));
50           System.out.println("Uppercase first names: " + upperCaseFirstNames);
51           // POINT F: Print a comma-separated list of all hyphenated last names
52           //          from the list of names in the names ArrayList.
53           String hyphenatedLastNames = names.stream()
54                   .map(n -> lastName(n))
55                   .filter(n -> n.contains("-"))
56                   .collect(Collectors.joining(" "));
57           System.out.println("Hypenated last names: " + hyphenatedLastNames);
58           // POINT G: Print the integer value of the total length of all names
59           //          in the names ArrayList.
60           int totalLength = names.stream()
61                   .map(n -> n.length())
62                   .reduce(0, (n1, n2) -> n1 + n2);
63           System.out.println("Total length: " + totalLength);
64           // POINT H: Print the integer value of the total length of all
65           //          first names in the names ArrayList.
66           int firstLength = names.stream()
67                   .map(n -> firstName(n))
68                   .map(n -> n.length())
69                   .reduce(0, (n1, n2) -> n1 + n2);
70           System.out.println("first length: " + firstLength);
71           // POINT I: Print the integer value of the product of the length of
72           //          all first names in the names ArrayList.
73           int lastLength = names.stream()
74                   .map(n -> lastName(n))
75                   .map(n -> n.length())
76                   .reduce(0, (n1, n2) -> n1 + n2);
77           System.out.println("last length: " + lastLength);
78   
79         }
80           private static String lastName(String directorStyleName) {
81               int length =directorStyleName.length();
82               int comma=directorStyleName.indexOf(",");
83               directorStyleName=directorStyleName.substring(0,comma+1);
84               return directorStyleName;
85           }
86       private static String firstName(String directorStyleName) {
87           int length =directorStyleName.length();
88           int comma=directorStyleName.indexOf(",");
89           comma=comma+1;
90           directorStyleName=directorStyleName.substring(comma,length);
91   
92           return directorStyleName;
93       }
94       }
95   
96