email validator java

1import java.util.regex.Matcher;
2
3import java.util.regex.Pattern;
4
5import java.util.Scanner;
6
7public class EmailValidator {
8
9	public static void main(String[] args) {
10
11		recursion();
12
13	}
14
15	static void recursion () {
16
17		Scanner scanner = new Scanner(System.in);
18
19		System.out.println("Welcome to the game of typing a correct email address!");
20		
21		System.out.println();
22		
23		System.out.println("As the game says, enter a correct email address.");
24
25		System.out.println();
26
27		String snow = scanner.nextLine();
28
29		String[] sssp = snow.split("@");
30		
31		if (sssp.length != 2) {
32			
33		System.out.println();
34			
35		System.out.println("This is not a correct email address.");	
36		
37		System.out.println();
38			
39		recursion();
40		
41		} else {
42
43			String regex = "[^a-z0-9._]";
44
45			String regex1 = "^\\.|\\.$";
46			
47			String regex2 = "\s";
48			
49			String regex3 = "^$";
50			
51			String regex7 = "\\._|_\\.";
52			
53			String regex39 = "__";
54			
55			String regex19 = "\\.\\.";
56			
57			String regex20 = "^_|_$";
58
59			Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);
60
61			Pattern pattern1 = Pattern.compile(regex1, Pattern.CASE_INSENSITIVE);
62			
63			Pattern pattern2 = Pattern.compile(regex2, Pattern.CASE_INSENSITIVE);
64			
65			Pattern pattern3 = Pattern.compile(regex3, Pattern.CASE_INSENSITIVE);
66			
67			Pattern pattern11 = Pattern.compile(regex7, Pattern.CASE_INSENSITIVE);
68			
69			Pattern pattern12 = Pattern.compile(regex19, Pattern.CASE_INSENSITIVE);
70			
71			Pattern pattern13 = Pattern.compile(regex20, Pattern.CASE_INSENSITIVE);
72			
73			Pattern pattern14 = Pattern.compile(regex39, Pattern.CASE_INSENSITIVE);
74
75			Matcher matcher = pattern.matcher(sssp[0]);
76
77			Matcher matcher1 = pattern1.matcher(sssp[0]);
78			
79			Matcher matcher2 = pattern2.matcher(sssp[0]);
80			
81			Matcher matcher3 = pattern3.matcher(sssp[0]);
82			
83			Matcher matcher11 = pattern11.matcher(sssp[0]);
84			
85			Matcher matcher12 = pattern12.matcher(sssp[0]);
86			
87			Matcher matcher13 = pattern13.matcher(sssp[0]);
88			
89			Matcher matcher14 = pattern14.matcher(sssp[0]);
90
91			boolean matchFound = matcher.find();
92
93			boolean matchFound1 = matcher1.find();
94			
95			boolean matchFound2 = matcher2.find();
96			
97			boolean matchFound3 = matcher3.find();
98			
99			boolean matchFound10 = matcher11.find();
100			
101			boolean matchFound11 = matcher12.find();
102			
103			boolean matchFound12 = matcher13.find();
104			
105			boolean matchFound13 = matcher14.find();
106			
107			String hello = sssp[1];
108			
109			String[] whoop = hello.split("\\.", 2);
110			
111			if (whoop.length != 2) {
112				
113			System.out.println();
114
115			System.out.println("This is not a correct email address.");	
116
117			System.out.println();	
118				
119			recursion();
120			
121			} else {
122				
123				String regex4 = "[^a-z]";
124				
125				String regex5 = "^$";
126				
127				String regex6 = "\s";
128				
129				Pattern pattern4 = Pattern.compile(regex4, Pattern.CASE_INSENSITIVE);
130
131				Pattern pattern5 = Pattern.compile(regex5, Pattern.CASE_INSENSITIVE);
132				
133				Pattern pattern6 = Pattern.compile(regex6, Pattern.CASE_INSENSITIVE);
134				
135				Matcher matcher4 = pattern4.matcher(whoop[0]);
136
137				Matcher matcher5 = pattern5.matcher(whoop[0]);
138				
139				Matcher matcher6 = pattern6.matcher(whoop[0]);
140				
141				boolean matchFound4 = matcher4.find();
142
143				boolean matchFound5 = matcher5.find();
144				
145				boolean matchFound6 = matcher6.find();
146				
147				Pattern pattern7 = Pattern.compile(regex4, Pattern.CASE_INSENSITIVE);
148
149				Pattern pattern8 = Pattern.compile(regex5, Pattern.CASE_INSENSITIVE);
150				
151				Pattern pattern9 = Pattern.compile(regex6, Pattern.CASE_INSENSITIVE);
152				
153				Matcher matcher7 = pattern7.matcher(whoop[1]);
154
155				Matcher matcher8 = pattern8.matcher(whoop[1]);
156				
157				Matcher matcher9 = pattern9.matcher(whoop[1]);
158				
159				boolean matchFound7 = matcher7.find();
160
161				boolean matchFound8 = matcher8.find();
162				
163				boolean matchFound9 = matcher9.find();
164				
165				System.out.println();
166
167				if(matchFound || matchFound1 || matchFound2 || matchFound3 || matchFound4 || matchFound5 || matchFound6 || matchFound7 || matchFound8 || matchFound9 || matchFound10 || matchFound11 || matchFound12 || matchFound13) {
168
169					System.out.println("This is not a correct email address.");
170
171					System.out.println();
172
173					recursion();
174
175				} else {
176
177					System.out.println("This is a correct email address.");
178
179					System.out.println();
180
181					System.out.println("Do you still want to play? (say yes to play) ");
182
183					System.out.println();
184
185					Scanner scanner1 = new Scanner(System.in);
186
187					String snow1 = scanner1.nextLine();
188
189					if (snow1.equalsIgnoreCase("yes")) {
190
191						System.out.println();
192
193						recursion();
194
195					} else {
196
197						System.out.println();  
198
199						System.out.println("Okay, then.");  
200						
201						scanner.close();
202						
203						scanner1.close();
204						
205					}
206
207				}	
208				
209			}
210			
211		}
212
213	}
214	
215}
216