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