Java Collection Transformations (arrays, List, Set, map conversions)

2. Package com.example.test;
6. Import java.util.ArrayList;
8. Import Java.util.Arrays;
10. Import Java.util.HashMap;
12. Import Java.util.HashSet;
14. Import java.util.List;
16. Import Java.util.Map;
18. Import Java.util.Set;
22. Public class Convertortest {
26. /** 
28. * @param args
30. */
32. public static void Main (string[] args) {
36. Testlist2array ();
38. Testarray2list ();
40. Testset2list ();
42. Testlist2set ();
44. Testset2array ();
46. Testarray2set ();
48. Testmap2set ();
50. Testmap2list ();
52. }
56. private static void Testmap2list () {
60. map<string, string> map = new hashmap<string, string> ();
62. Map.put ("A", "ABC");
64. Map.put ("K", "KK");
66. Map.put ("L", "LV");
70. //Convert map Key to list
72. list<string> mapkeylist = new Arraylist<string> (Map.keyset ());
74. System.out.println ("mapkeylist:" +mapkeylist);
78. //Convert map Key to list
80. list<string> mapvalueslist = new Arraylist<string> (Map.values ());
82. System.out.println ("mapvalueslist:" +mapvalueslist);
86. }
90. private static void Testmap2set () {
94. map<string, string> map = new hashmap<string, string> ();
96. Map.put ("A", "ABC");
98. Map.put ("K", "KK");
100. Map.put ("L", "LV");
104. //Convert the map's key to set
106. set<string> Mapkeyset = Map.keyset ();
108. System.out.println ("Mapkeyset:" +mapkeyset);
112. //Convert the value of map to set
114. set<string> Mapvaluesset = new Hashset<string> (Map.values ());
116. System.out.println ("Mapvaluesset:" +mapvaluesset);
118. }
122. private static void Testarray2set () {
126. String[] arr = {"AA","BB","DD","CC","BB"};
130. //Array-->set
132. set<string> set = new Hashset<string> (Arrays.aslist (arr));
134. SYSTEM.OUT.PRINTLN (set);
136. }
140. private static void Testset2array () {
142. set<string> set = new hashset<string> ();
144. Set.add ("AA");
146. Set.add ("BB");
148. Set.add ("CC");
152. string[] arr = new String[set.size ()];
154. //set--> Array
156. Set.toarray (arr);
158. System.out.println (arrays.tostring (arr));
160. }
164. private static void Testlist2set () {
168. list<string> list = new arraylist<string> ();
170. List.add ("ABC");
172. List.add ("EFG");
174. List.add ("LMN");
176. List.add ("LMN");
180. //list-->set
182. set<string> listset = new hashset<string> (list);
184. System.out.println (Listset);
186. }
190. private static void Testset2list () {
194. set<string> set = new hashset<string> ();
196. Set.add ("AA");
198. Set.add ("BB");
200. Set.add ("CC");
204. //set-List
206. List<string> setlist = new arraylist<string> (set);
208. System.out.println (setlist);
210. }
214. private static void Testlist2array () {
216. //list--> Array
218. list<string> list = new arraylist<string> ();
220. List.add ("AA");
222. List.add ("BB");
224. List.add ("CC");
226. Object[] objects = List.toarray (); //Returns an object array
228. System.out.println ("Objects:" +arrays.tostring (objects));
232. string[] arr = new String[list.size ()];
234. List.toarray (arr); //Convert the converted array into an already created object
236. System.out.println ("STRINGS1:" +arrays.tostring (arr));
238. }
242. private static void Testarray2list () {
244. //Array-->list
246. string[] ss = {"JJ","KK"};
248. List<string> List1 = arrays.aslist (ss);
250. List<string> List2 = arrays.aslist ("AAA","BBB");
252. System.out.println (List1);
254. System.out.println (LIST2);
256. }
260. }

Java Collection Transformations (arrays, List, Set, map conversions)