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StreamArrayListProcessing.java
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1 /*
2 * A program to perform some basic operations on a list of strings
3 */
4
5 package arraylists;
6
7 import java.util.ArrayList;
8 import java.util.List;
9 import java.util.stream.Collectors;
10
11
12 public class StreamArrayListProcessing {
13
14 public static void main(String[] args) {
15 //POINT A : Add some strings which represent names to an ArrayList.
16 List<String> names = new ArrayList<>();
17 names.add("Holiday, Billie");
18 names.add("Claudel, Camille");
19 names.add("Picasso, Pablo");
20 names.add("Gallen-Kallela, Akseli");
21 names.add("Zotto, Osvaldo");
22 names.add("Mishra, Neeraj");
23 names.add("Rauniyar, Adarsh");
24
25 List<String> firstNamesList = names.stream()
26 .map(n -> firstName(n))
27 .collect(Collectors.toList());
28
29 System.out.println("first names: ");
30 for (String firstName : firstNamesList) {
31 System.out.println(firstName + " ");
32 }
33 System.out.println();
34
35 String firstNames = String.join(" ,", firstNamesList);
36
37 System.out.println("firstNames: " + firstNames);
38
39 List<String> lastNamesList = names.stream()
40 .map(n -> lastName(n))
41 .collect(Collectors.toList());
42
43
44 System.out.println("last names: ");
45 for (String lastName : lastNamesList) {
46 System.out.println(lastName + " ");
47 }
48 System.out.println();
49
50 String lastNames = String.join(" ,", lastNamesList);
51
52 System.out.println("lastNames: " + lastNames);
53
54 String upperCaseFirstNames = names.stream()
55 .map(n -> firstName(n))
56 .map(n -> n.toUpperCase())
57 .collect(Collectors.joining(","));
58
59 System.out.println("Uppercase first names: " + upperCaseFirstNames);
60
61 String hyphenatedLastNames = names.stream()
62 .map(n -> lastName(n))
63 .filter(n -> n.contains("-"))
64 .collect(Collectors.joining());
65
66 System.out.println("Hyphenated Last names: " + hyphenatedLastNames);
67
68 int totalLength = names.stream()
69 .map(n -> n.length())
70 .reduce(0, (n1, n2) -> n1 + n2);
71
72 System.out.println("Total length: " + totalLength);
73
74 int totalfirstlength = firstNamesList.stream()
75 .map(n -> n.length())
76 .reduce(0, (n1, n2) -> n1 + n2);
77
78 System.out.println(" Totalfirst length: " + totalfirstlength);
79
80 int totalProduct = names.stream()
81 .map(n -> n.length())
82 .reduce(1, (n1, n2) -> n1 * n2);
83
84 System.out.println(" Total Product: " + totalProduct);
85
86
87 }
88
89
90 private static String firstName(String directoryStyleName) {
91 int commaposition = directoryStyleName.indexOf(",");
92 return directoryStyleName.substring(commaposition + 1);
93 }
94
95 private static List<String> firstNames(List<String> names) {
96 List<String> firsts = new ArrayList<>();
97 for (String name : names) {
98 firsts.add(firstName(name));
99 }
100 return firsts;
101 }
102
103 private static String lastName(String directoryStyleName) {
104 int commaposition = directoryStyleName.indexOf(",");
105 return directoryStyleName.substring(0, commaposition);
106 }
107
108 private static List<String> lastNames(List<String> names) {
109 List<String> firsts = new ArrayList<>();
110 for (String name : names) {
111 firsts.add(lastName(name));
112 }
113 return firsts;
114 }
115
116 public static List<String> upperCaseNames(List<String> names) {
117 List<String> uppercases = new ArrayList<>();
118 for (String name : names) {
119 uppercases.add(name.toUpperCase());
120 }
121 return uppercases;
122 }
123
124 public static List<String> hyphenatedNames(List<String> names) {
125 List<String> hyphenateds = new ArrayList<>();
126 for (String name : names) {
127 if (name.contains("-")) {
128 hyphenateds.add(name);
129 }
130 }
131 return hyphenateds;
132 }
133
134 public static int totalNameLength(List<String> names) {
135 int totalLength = 0;
136 for (String name : names) {
137 totalLength = totalLength + name.length();
138 }
139 return totalLength;
140 }
141
142 public static int totalNameProduct(List<String> names) {
143 int totalProduct = 1;
144 for (String name : names) {
145 totalProduct = totalProduct * name.length();
146 }
147 return totalProduct;
148
149
150 }
151
152 }
153