Refactored code: added database status check in methods, replaced

NullPointerException with IllegarlArgumentException, fixed SQL create
method, improved code…

src/fr/devinsy/sikevadb/core/ClosedDatabaseException.java

@@ -22,23 +22,23 @@ package fr.devinsy.sikevadb.core;
  * 
  * @author Christian Pierre MOMON (christian.momon@devinsy.fr)
  */
-public class UnopenedDatabaseException extends SikevaDBException
+public class ClosedDatabaseException extends SikevaDBException
 {
 	private static final long serialVersionUID = 8364599416669077052L;
 
 	/**
 	 * 
 	 */
-	public UnopenedDatabaseException()
+	public ClosedDatabaseException()
 	{
-		super();
+		super("Invalid database status for this operation: closed.");
 	}
 
 	/**
 	 * 
 	 * @param message
 	 */
-	public UnopenedDatabaseException(final String message)
+	public ClosedDatabaseException(final String message)
 	{
 		super(message);
 	}
@@ -48,7 +48,7 @@ public class UnopenedDatabaseException extends SikevaDBException
 	 * @param message
 	 * @param cause
 	 */
-	public UnopenedDatabaseException(final String message, final Throwable cause)
+	public ClosedDatabaseException(final String message, final Throwable cause)
 	{
 		super(message, cause);
 	}
@@ -57,7 +57,7 @@ public class UnopenedDatabaseException extends SikevaDBException
 	 * 
 	 * @param cause
 	 */
-	public UnopenedDatabaseException(final Throwable cause)
+	public ClosedDatabaseException(final Throwable cause)
 	{
 		super(cause);
 	}

src/fr/devinsy/sikevadb/core/OpenedDatabaseException.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2018 Christian Pierre MOMON <christian.momon@devinsy.fr>
+ * 
+ * This file is part of SikevaDB, simple key value database.
+ * 
+ * SikevaDB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ * 
+ * SikevaDB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with SikevaDB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package fr.devinsy.sikevadb.core;
+
+/**
+ * 
+ * @author Christian Pierre MOMON (christian.momon@devinsy.fr)
+ */
+public class OpenedDatabaseException extends SikevaDBException
+{
+	private static final long serialVersionUID = 8364599416669077052L;
+
+	/**
+	 * 
+	 */
+	public OpenedDatabaseException()
+	{
+		super("Invalid database status for this operation: opened.");
+	}
+
+	/**
+	 * 
+	 * @param message
+	 */
+	public OpenedDatabaseException(final String message)
+	{
+		super(message);
+	}
+
+	/**
+	 * 
+	 * @param message
+	 * @param cause
+	 */
+	public OpenedDatabaseException(final String message, final Throwable cause)
+	{
+		super(message, cause);
+	}
+
+	/**
+	 * 
+	 * @param cause
+	 */
+	public OpenedDatabaseException(final Throwable cause)
+	{
+		super(cause);
+	}
+}

src/fr/devinsy/sikevadb/core/XMLSikevaDB.java

@@ -81,11 +81,11 @@ public class XMLSikevaDB
 	{
 		if (out == null)
 		{
-			throw new NullPointerException("out is null.");
+			throw new IllegalArgumentException("out is null.");
 		}
 		else if (source == null)
 		{
-			throw new NullPointerException("source is null.");
+			throw new IllegalArgumentException("source is null.");
 		}
 		else if (fileName == null)
 		{
@@ -249,11 +249,11 @@ public class XMLSikevaDB
 
 		if (out == null)
 		{
-			throw new NullPointerException("out is null.");
+			throw new IllegalArgumentException("out is null.");
 		}
 		else if (source == null)
 		{
-			throw new NullPointerException("element is null.");
+			throw new IllegalArgumentException("element is null.");
 		}
 		else
 		{
@@ -307,7 +307,7 @@ public class XMLSikevaDB
 	{
 		if (out == null)
 		{
-			throw new NullPointerException("out is null.");
+			throw new IllegalArgumentException("out is null.");
 		}
 		else if (source == null)
 		{

test/fr/devinsy/sikevadb/sql/SQLSikevaDBTest.java

@@ -701,7 +701,7 @@ public class SQLSikevaDBTest
 		// "12345678");
 
 		database = new SQLSikevaDB("org.hsqldb.jdbcDriver", "jdbc:hsqldb:mem:sikevadb-unittest;sql.syntax_mys=true", "sa", "");
-		database.open();
 		database.create();
+		database.open();
 	}
 }