Add signin module.

src/main/java/org/codiki/account/AccountService.java

@@ -1,6 +1,7 @@
 package org.codiki.account;
 
 import java.io.IOException;
+import java.util.Date;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
@@ -121,4 +122,22 @@ public class AccountService {
 		
 		return result;
 	}
+
+	public UserDTO signin(final UserDTO pUser, final HttpServletResponse pResponse) throws IOException {
+		User user = new User();
+		
+		if(pUser.getName() == null || pUser.getEmail() == null || pUser.getPassword() == null || "".equals(pUser.getPassword().trim())) {
+			pResponse.sendError(HttpServletResponse.SC_BAD_REQUEST);
+		} else if(userRepository.findByEmail(pUser.getEmail()).isPresent()) {
+			pResponse.sendError(HttpServletResponse.SC_CONFLICT);
+		} else {
+			user.setName(pUser.getName());
+			user.setEmail(pUser.getEmail());
+			user.setPassword(StringUtils.hashPassword(pUser.getPassword()));
+			user.setInscriptionDate(new Date());
+			userRepository.save(user);
+		}
+		
+		return new UserDTO(user);
+	}
 }