From 6de31fbc8af3a028000a0c9e8393fb564dee1318 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Roland=20H=C3=A4der?= <roland@mxchange.org>
Date: Thu, 21 Apr 2016 15:50:55 +0200
Subject: [PATCH] Implemented business method ifUserNameExists()

---
 .../user/AddressbookUserSessionBean.java      | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/src/java/org/mxchange/jusercore/model/user/AddressbookUserSessionBean.java b/src/java/org/mxchange/jusercore/model/user/AddressbookUserSessionBean.java
index a4b903b..cb012dc 100644
--- a/src/java/org/mxchange/jusercore/model/user/AddressbookUserSessionBean.java
+++ b/src/java/org/mxchange/jusercore/model/user/AddressbookUserSessionBean.java
@@ -380,6 +380,47 @@ public class AddressbookUserSessionBean extends BaseDatabaseBean implements User
 		return true;
 	}
 
+	@Override
+	public boolean ifUserNameExists (final String userName) {
+		// Trace message
+		this.getLoggerBeanLocal().logTrace(MessageFormat.format("ifUserNameExists: userName={0} - CALLED!", userName)); //NOI18N
+
+		// userId should not be null
+		if (null == userName) {
+			// Abort here
+			throw new NullPointerException("userName is null"); //NOI18N
+		} else if (userName.isEmpty()) {
+			// Abort here
+			throw new NullPointerException("userName is empty"); //NOI18N
+		}
+
+		// Generate query
+		Query query = this.getEntityManager().createNamedQuery("SearchUserName", LoginUser.class); //NOI18N
+
+		// Set parameter
+		query.setParameter("param", userName); //NOI18N
+
+		// Try this
+		try {
+			User dummy = (User) query.getSingleResult();
+
+			// Debug message
+			this.getLoggerBeanLocal().logDebug(MessageFormat.format("ifUserNameExists: dummy.id={0} found.", dummy.getUserId())); //NOI18N
+		} catch (final NoResultException ex) {
+			// Log it
+			this.getLoggerBeanLocal().logDebug(MessageFormat.format("ifUserNameExists: getSingleResult() returned no result: {0}", ex)); //NOI18N
+
+			// User name does not exist
+			return false;
+		}
+
+		// Trace message
+		this.getLoggerBeanLocal().logTrace(MessageFormat.format("ifUserNameExists: Found user name {0} - EXIT!", userName)); //NOI18N
+
+		// Found it
+		return true;
+	}
+
 	@Override
 	public boolean isEmailAddressReqistered (final User user) {
 		// Trace message
-- 
2.39.5