Move close methods out of sql datasource utils class

As noticed by @Gnat008
- We need two different implementations for MySQL and SQLite because SQLite uses an older version where #isClosed is not implemented

src/main/java/fr/xephi/authme/datasource/MySQL.java

@@ -29,7 +29,6 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-import static fr.xephi.authme.datasource.SqlDataSourceUtils.close;
 import static fr.xephi.authme.datasource.SqlDataSourceUtils.logSqlException;
 
 public class MySQL implements DataSource {
@@ -979,12 +978,42 @@ public class MySQL implements DataSource {
             .build();
     }
 
+    /**
+     * Closes a {@link ResultSet} safely.
+     *
+     * @param rs the result set to close
+     */
+    private static void close(ResultSet rs) {
+        try {
+            if (rs != null && !rs.isClosed()) {
+                rs.close();
+            }
+        } catch (SQLException e) {
+            ConsoleLogger.logException("Could not close ResultSet", e);
+        }
+    }
+
+    /**
+     * Closes a {@link Statement} safely.
+     *
+     * @param st the statement set to close
+     */
+    private static void close(Statement st) {
+        try {
+            if (st != null && !st.isClosed()) {
+                st.close();
+            }
+        } catch (SQLException e) {
+            ConsoleLogger.logException("Could not close Statement", e);
+        }
+    }
+
     /**
      * Checks if the last login column has a type that needs to be migrated.
      *
      * @param con connection to the database
      * @param metaData lastlogin column meta data
-     * @throws SQLException
+     * @throws SQLException .
      */
     private void migrateLastLoginColumn(Connection con, DatabaseMetaData metaData) throws SQLException {
         final int columnType;

src/main/java/fr/xephi/authme/datasource/SqlDataSourceUtils.java

@@ -2,10 +2,7 @@ package fr.xephi.authme.datasource;
 
 import fr.xephi.authme.ConsoleLogger;
 
-import java.sql.Connection;
-import java.sql.ResultSet;
 import java.sql.SQLException;
-import java.sql.Statement;
 
 /**
  * Utilities for SQL data sources.
@@ -23,53 +20,4 @@ final class SqlDataSourceUtils {
     static void logSqlException(SQLException e) {
         ConsoleLogger.logException("Error during SQL operation:", e);
     }
-
-
-    // We use overloaded close() methods instead of one close(AutoCloseable) method in order to limit the
-    // checked exceptions to SQLException, which is the only checked exception these classes throw.
-
-    /**
-     * Closes a {@link ResultSet} safely.
-     *
-     * @param rs the result set to close
-     */
-    static void close(ResultSet rs) {
-        try {
-            if (rs != null && !rs.isClosed()) {
-                rs.close();
-            }
-        } catch (SQLException e) {
-            ConsoleLogger.logException("Could not close ResultSet", e);
-        }
-    }
-
-    /**
-     * Closes a {@link Statement} safely.
-     *
-     * @param st the statement set to close
-     */
-    static void close(Statement st) {
-        try {
-            if (st != null && !st.isClosed()) {
-                st.close();
-            }
-        } catch (SQLException e) {
-            ConsoleLogger.logException("Could not close Statement", e);
-        }
-    }
-
-    /**
-     * Closes a {@link Connection} safely.
-     *
-     * @param con the connection set to close
-     */
-    static void close(Connection con) {
-        try {
-            if (con != null && !con.isClosed()) {
-                con.close();
-            }
-        } catch (SQLException e) {
-            ConsoleLogger.logException("Could not close Connection", e);
-        }
-    }
 }