#1255 Simplify MySQL data source extensions

- Mostly oving the logic of getting the ID from the DB to the extensions superclass

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

@@ -85,6 +85,7 @@ public class MySQL implements DataSource {
      * Retrieves various settings.
      *
      * @param settings the settings to read properties from
+     * @param extensionsFactory factory to create the MySQL extension
      */
     private void setParameters(Settings settings, MySqlExtensionsFactory extensionsFactory) {
         this.host = settings.getProperty(DatabaseSettings.MYSQL_HOST);
@@ -435,8 +436,8 @@ public class MySQL implements DataSource {
     @Override
     public boolean updateQuitLoc(PlayerAuth auth) {
         String sql = "UPDATE " + tableName
-            + " SET " + col.LASTLOC_X + " =?, " + col.LASTLOC_Y + "=?, " + col.LASTLOC_Z + "=?, " + col.LASTLOC_WORLD + "=?, "
+            + " SET " + col.LASTLOC_X + " =?, " + col.LASTLOC_Y + "=?, " + col.LASTLOC_Z + "=?, "
-            + col.LASTLOC_YAW + "=?, " + col.LASTLOC_PITCH + "=?"
+            + col.LASTLOC_WORLD + "=?, " + col.LASTLOC_YAW + "=?, " + col.LASTLOC_PITCH + "=?"
             + " WHERE " + col.NAME + "=?;";
         try (Connection con = getConnection(); PreparedStatement pst = con.prepareStatement(sql)) {
             pst.setDouble(1, auth.getQuitLocX());

src/main/java/fr/xephi/authme/datasource/mysqlextensions/Ipb4Extension.java

@@ -3,12 +3,10 @@ package fr.xephi.authme.datasource.mysqlextensions;
 import fr.xephi.authme.data.auth.PlayerAuth;
 import fr.xephi.authme.datasource.Columns;
 import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.settings.properties.DatabaseSettings;
 import fr.xephi.authme.settings.properties.HooksSettings;
 
 import java.sql.Connection;
 import java.sql.PreparedStatement;
-import java.sql.ResultSet;
 import java.sql.SQLException;
 
 /**
@@ -16,53 +14,42 @@ import java.sql.SQLException;
  */
 class Ipb4Extension extends MySqlExtension {
 
-    private final Columns col;
-    private final String tableName;
     private final String ipbPrefix;
     private final int ipbGroup;
 
     Ipb4Extension(Settings settings, Columns col) {
-        this.col = col;
+        super(settings, col);
-        this.tableName = settings.getProperty(DatabaseSettings.MYSQL_TABLE);
         this.ipbPrefix = settings.getProperty(HooksSettings.IPB_TABLE_PREFIX);
         this.ipbGroup = settings.getProperty(HooksSettings.IPB_ACTIVATED_GROUP_ID);
     }
 
     @Override
     public void saveAuth(PlayerAuth auth, Connection con) throws SQLException {
-        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        // Update player group in core_members
-        try (PreparedStatement pst = con.prepareStatement(sql)) {
+        String sql = "UPDATE " + ipbPrefix + tableName
-            pst.setString(1, auth.getNickname());
+                   + " SET " + tableName + ".member_group_id=? WHERE " + col.NAME + "=?;";
-            try (ResultSet rs = pst.executeQuery()) {
+        try (PreparedStatement pst2 = con.prepareStatement(sql)) {
-                if (rs.next()) {
+            pst2.setInt(1, ipbGroup);
-                    // Update player group in core_members
+            pst2.setString(2, auth.getNickname());
-                    sql = "UPDATE " + ipbPrefix + tableName
+            pst2.executeUpdate();
-                        + " SET " + tableName + ".member_group_id=? WHERE " + col.NAME + "=?;";
+        }
-                    try (PreparedStatement pst2 = con.prepareStatement(sql)) {
+        // Get current time without ms
-                        pst2.setInt(1, ipbGroup);
+        long time = System.currentTimeMillis() / 1000;
-                        pst2.setString(2, auth.getNickname());
+        // update joined date
-                        pst2.executeUpdate();
+        sql = "UPDATE " + ipbPrefix + tableName
-                    }
+            + " SET " + tableName + ".joined=? WHERE " + col.NAME + "=?;";
-                    // Get current time without ms
+        try (PreparedStatement pst2 = con.prepareStatement(sql)) {
-                    long time = System.currentTimeMillis() / 1000;
+            pst2.setLong(1, time);
-                    // update joined date
+            pst2.setString(2, auth.getNickname());
-                    sql = "UPDATE " + ipbPrefix + tableName
+            pst2.executeUpdate();
-                        + " SET " + tableName + ".joined=? WHERE " + col.NAME + "=?;";
+        }
-                    try (PreparedStatement pst2 = con.prepareStatement(sql)) {
+        // Update last_visit
-                        pst2.setLong(1, time);
+        sql = "UPDATE " + ipbPrefix + tableName
-                        pst2.setString(2, auth.getNickname());
+            + " SET " + tableName + ".last_visit=? WHERE " + col.NAME + "=?;";
-                        pst2.executeUpdate();
+        try (PreparedStatement pst2 = con.prepareStatement(sql)) {
-                    }
+            pst2.setLong(1, time);
-                    // Update last_visit
+            pst2.setString(2, auth.getNickname());
-                    sql = "UPDATE " + ipbPrefix + tableName
+            pst2.executeUpdate();
-                        + " SET " + tableName + ".last_visit=? WHERE " + col.NAME + "=?;";
-                    try (PreparedStatement pst2 = con.prepareStatement(sql)) {
-                        pst2.setLong(1, time);
-                        pst2.setString(2, auth.getNickname());
-                        pst2.executeUpdate();
-                    }
-                }
-            }
         }
     }
 }

src/main/java/fr/xephi/authme/datasource/mysqlextensions/MySqlExtension.java

@@ -1,10 +1,16 @@
 package fr.xephi.authme.datasource.mysqlextensions;
 
 import fr.xephi.authme.data.auth.PlayerAuth;
+import fr.xephi.authme.datasource.Columns;
 import fr.xephi.authme.security.crypts.HashedPassword;
+import fr.xephi.authme.settings.Settings;
+import fr.xephi.authme.settings.properties.DatabaseSettings;
 
 import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.OptionalInt;
 
 /**
  * Extension for the MySQL data source for forums. For certain password hashes (e.g. phpBB), we want
@@ -12,6 +18,14 @@ import java.sql.SQLException;
  */
 public abstract class MySqlExtension {
 
+    protected final Columns col;
+    protected final String tableName;
+
+    MySqlExtension(Settings settings, Columns col) {
+        this.col = col;
+        this.tableName = settings.getProperty(DatabaseSettings.MYSQL_TABLE);
+    }
+
     /**
      * Performs additional actions when a new player is saved.
      *
@@ -59,4 +73,24 @@ public abstract class MySqlExtension {
         // extend for custom behavior
     }
 
+    /**
+     * Fetches the database ID of the given name from the database.
+     *
+     * @param name the name to get the ID for
+     * @param con connection to the sql table
+     * @return id of the playerAuth, or empty OptionalInt if the name is not registered
+     * @throws SQLException .
+     */
+    protected OptionalInt retrieveIdFromTable(String name, Connection con) throws SQLException {
+        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        try (PreparedStatement pst = con.prepareStatement(sql)) {
+            pst.setString(1, name);
+            try (ResultSet rs = pst.executeQuery()) {
+                if (rs.next()) {
+                    return OptionalInt.of(rs.getInt(col.ID));
+                }
+            }
+        }
+        return OptionalInt.empty();
+    }
 }

src/main/java/fr/xephi/authme/datasource/mysqlextensions/MySqlExtensionsFactory.java

@@ -15,6 +15,12 @@ public class MySqlExtensionsFactory {
     @Inject
     private Settings settings;
 
+    /**
+     * Creates a new {@link MySqlExtension} object according to the configured hash algorithm.
+     *
+     * @param columnsConfig the columns configuration
+     * @return the extension the MySQL data source should use
+     */
     public MySqlExtension buildExtension(Columns columnsConfig) {
         HashAlgorithm hash = settings.getProperty(SecuritySettings.PASSWORD_HASH);
         switch (hash) {
@@ -27,7 +33,7 @@ public class MySqlExtensionsFactory {
             case XFBCRYPT:
                 return new XfBcryptExtension(settings, columnsConfig);
             default:
-                return new NoOpExtension();
+                return new NoOpExtension(settings, columnsConfig);
         }
     }
 }

src/main/java/fr/xephi/authme/datasource/mysqlextensions/NoOpExtension.java

@@ -1,7 +1,14 @@
 package fr.xephi.authme.datasource.mysqlextensions;
 
+import fr.xephi.authme.datasource.Columns;
+import fr.xephi.authme.settings.Settings;
+
 /**
  * Extension implementation that does not do anything.
  */
 class NoOpExtension extends MySqlExtension {
+
+    NoOpExtension(Settings settings, Columns col) {
+        super(settings, col);
+    }
 }

src/main/java/fr/xephi/authme/datasource/mysqlextensions/PhpBbExtension.java

@@ -3,42 +3,32 @@ package fr.xephi.authme.datasource.mysqlextensions;
 import fr.xephi.authme.data.auth.PlayerAuth;
 import fr.xephi.authme.datasource.Columns;
 import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.settings.properties.DatabaseSettings;
 import fr.xephi.authme.settings.properties.HooksSettings;
 
 import java.sql.Connection;
 import java.sql.PreparedStatement;
-import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.OptionalInt;
 
 /**
  * Extensions for phpBB when MySQL is used as data source.
  */
 class PhpBbExtension extends MySqlExtension {
 
-    private final Columns col;
-    private final String tableName;
     private final String phpBbPrefix;
     private final int phpBbGroup;
 
     PhpBbExtension(Settings settings, Columns col) {
-        this.col = col;
+        super(settings, col);
-        this.tableName = settings.getProperty(DatabaseSettings.MYSQL_TABLE);
         this.phpBbPrefix = settings.getProperty(HooksSettings.PHPBB_TABLE_PREFIX);
         this.phpBbGroup = settings.getProperty(HooksSettings.PHPBB_ACTIVATED_GROUP_ID);
     }
 
     @Override
     public void saveAuth(PlayerAuth auth, Connection con) throws SQLException {
-        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        OptionalInt authId = retrieveIdFromTable(auth.getNickname(), con);
-        try (PreparedStatement pst = con.prepareStatement(sql)) {
+        if (authId.isPresent()) {
-            pst.setString(1, auth.getNickname());
+            updateSpecificsOnSave(authId.getAsInt(), auth.getNickname(), con);
-            try (ResultSet rs = pst.executeQuery()) {
-                if (rs.next()) {
-                    int id = rs.getInt(col.ID);
-                    updateSpecificsOnSave(id, auth.getNickname(), con);
-                }
-            }
         }
     }
 

src/main/java/fr/xephi/authme/datasource/mysqlextensions/WordpressExtension.java

@@ -3,105 +3,100 @@ package fr.xephi.authme.datasource.mysqlextensions;
 import fr.xephi.authme.data.auth.PlayerAuth;
 import fr.xephi.authme.datasource.Columns;
 import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.settings.properties.DatabaseSettings;
 import fr.xephi.authme.settings.properties.HooksSettings;
 
 import java.sql.Connection;
 import java.sql.PreparedStatement;
-import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.OptionalInt;
 
 /**
  * MySQL extensions for Wordpress.
  */
 class WordpressExtension extends MySqlExtension {
 
-    private final Columns col;
-    private final String tableName;
     private final String wordpressPrefix;
 
     WordpressExtension(Settings settings, Columns col) {
-        this.col = col;
+        super(settings, col);
-        this.tableName = settings.getProperty(DatabaseSettings.MYSQL_TABLE);
         this.wordpressPrefix = settings.getProperty(HooksSettings.WORDPRESS_TABLE_PREFIX);
     }
 
     @Override
     public void saveAuth(PlayerAuth auth, Connection con) throws SQLException {
-        try (PreparedStatement pst = con.prepareStatement("SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;")) {
+        OptionalInt authId = retrieveIdFromTable(auth.getNickname(), con);
-            pst.setString(1, auth.getNickname());
+        if (authId.isPresent()) {
-            try (ResultSet rs = pst.executeQuery()) {
+            saveSpecifics(auth, authId.getAsInt(), con);
-                if (rs.next()) {
+        }
-                    int id = rs.getInt(col.ID);
+    }
-                    String sql = "INSERT INTO " + wordpressPrefix + "usermeta (user_id, meta_key, meta_value) VALUES (?,?,?)";
-                    try (PreparedStatement pst2 = con.prepareStatement(sql)) {
-                        // First Name
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "first_name");
-                        pst2.setString(3, "");
-                        pst2.addBatch();
-                        // Last Name
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "last_name");
-                        pst2.setString(3, "");
-                        pst2.addBatch();
-                        // Nick Name
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "nickname");
-                        pst2.setString(3, auth.getNickname());
-                        pst2.addBatch();
-                        // Description
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "description");
-                        pst2.setString(3, "");
-                        pst2.addBatch();
-                        // Rich_Editing
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "rich_editing");
-                        pst2.setString(3, "true");
-                        pst2.addBatch();
-                        // Comments_Shortcuts
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "comment_shortcuts");
-                        pst2.setString(3, "false");
-                        pst2.addBatch();
-                        // admin_color
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "admin_color");
-                        pst2.setString(3, "fresh");
-                        pst2.addBatch();
-                        // use_ssl
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "use_ssl");
-                        pst2.setString(3, "0");
-                        pst2.addBatch();
-                        // show_admin_bar_front
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "show_admin_bar_front");
-                        pst2.setString(3, "true");
-                        pst2.addBatch();
-                        // wp_capabilities
-                        pst2.setInt(1, id);
-                        pst2.setString(2, wordpressPrefix + "capabilities");
-                        pst2.setString(3, "a:1:{s:10:\"subscriber\";b:1;}");
-                        pst2.addBatch();
-                        // wp_user_level
-                        pst2.setInt(1, id);
-                        pst2.setString(2, wordpressPrefix + "user_level");
-                        pst2.setString(3, "0");
-                        pst2.addBatch();
-                        // default_password_nag
-                        pst2.setInt(1, id);
-                        pst2.setString(2, "default_password_nag");
-                        pst2.setString(3, "");
-                        pst2.addBatch();
 
-                        // Execute queries
+    private void saveSpecifics(PlayerAuth auth, int id, Connection con) throws SQLException {
-                        pst2.executeBatch();
+        String sql = "INSERT INTO " + wordpressPrefix + "usermeta (user_id, meta_key, meta_value) VALUES (?,?,?)";
-                        pst2.clearBatch();
+        try (PreparedStatement pst = con.prepareStatement(sql)) {
-                    }
+            // First Name
-                }
+            pst.setInt(1, id);
-            }
+            pst.setString(2, "first_name");
+            pst.setString(3, "");
+            pst.addBatch();
+            // Last Name
+            pst.setInt(1, id);
+            pst.setString(2, "last_name");
+            pst.setString(3, "");
+            pst.addBatch();
+            // Nick Name
+            pst.setInt(1, id);
+            pst.setString(2, "nickname");
+            pst.setString(3, auth.getNickname());
+            pst.addBatch();
+            // Description
+            pst.setInt(1, id);
+            pst.setString(2, "description");
+            pst.setString(3, "");
+            pst.addBatch();
+            // Rich_Editing
+            pst.setInt(1, id);
+            pst.setString(2, "rich_editing");
+            pst.setString(3, "true");
+            pst.addBatch();
+            // Comments_Shortcuts
+            pst.setInt(1, id);
+            pst.setString(2, "comment_shortcuts");
+            pst.setString(3, "false");
+            pst.addBatch();
+            // admin_color
+            pst.setInt(1, id);
+            pst.setString(2, "admin_color");
+            pst.setString(3, "fresh");
+            pst.addBatch();
+            // use_ssl
+            pst.setInt(1, id);
+            pst.setString(2, "use_ssl");
+            pst.setString(3, "0");
+            pst.addBatch();
+            // show_admin_bar_front
+            pst.setInt(1, id);
+            pst.setString(2, "show_admin_bar_front");
+            pst.setString(3, "true");
+            pst.addBatch();
+            // wp_capabilities
+            pst.setInt(1, id);
+            pst.setString(2, wordpressPrefix + "capabilities");
+            pst.setString(3, "a:1:{s:10:\"subscriber\";b:1;}");
+            pst.addBatch();
+            // wp_user_level
+            pst.setInt(1, id);
+            pst.setString(2, wordpressPrefix + "user_level");
+            pst.setString(3, "0");
+            pst.addBatch();
+            // default_password_nag
+            pst.setInt(1, id);
+            pst.setString(2, "default_password_nag");
+            pst.setString(3, "");
+            pst.addBatch();
+
+            // Execute queries
+            pst.executeBatch();
+            pst.clearBatch();
         }
     }
 }

src/main/java/fr/xephi/authme/datasource/mysqlextensions/XfBcryptExtension.java

@@ -5,7 +5,6 @@ import fr.xephi.authme.datasource.Columns;
 import fr.xephi.authme.security.crypts.HashedPassword;
 import fr.xephi.authme.security.crypts.XfBCrypt;
 import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.settings.properties.DatabaseSettings;
 import fr.xephi.authme.settings.properties.HooksSettings;
 
 import java.sql.Blob;
@@ -13,35 +12,27 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.OptionalInt;
 
 /**
  * Extension for XFBCRYPT.
  */
 class XfBcryptExtension extends MySqlExtension {
     
-    private final Columns col;
-    private final String tableName;
     private final String xfPrefix;
     private final int xfGroup;
     
     XfBcryptExtension(Settings settings, Columns col) {
-        this.col = col;
+        super(settings, col);
-        this.tableName = settings.getProperty(DatabaseSettings.MYSQL_TABLE);
         this.xfPrefix = settings.getProperty(HooksSettings.XF_TABLE_PREFIX);
         this.xfGroup = settings.getProperty(HooksSettings.XF_ACTIVATED_GROUP_ID);
     }
 
     @Override
     public void saveAuth(PlayerAuth auth, Connection con) throws SQLException {
-        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        OptionalInt authId = retrieveIdFromTable(auth.getNickname(), con);
-        try (PreparedStatement pst = con.prepareStatement(sql)) {
+        if (authId.isPresent()) {
-            pst.setString(1, auth.getNickname());
+            updateXenforoTablesOnSave(auth, authId.getAsInt(), con);
-            try (ResultSet rs = pst.executeQuery()) {
-                if (rs.next()) {
-                    int id = rs.getInt(col.ID);
-                    updateXenforoTablesOnSave(auth, id, con);
-                }
-            }
         }
     }
     
@@ -110,50 +101,39 @@ class XfBcryptExtension extends MySqlExtension {
 
     @Override
     public void changePassword(String user, HashedPassword password, Connection con) throws SQLException {
-        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        OptionalInt authId = retrieveIdFromTable(user, con);
-        try (PreparedStatement pst = con.prepareStatement(sql)) {
+        if (authId.isPresent()) {
-            pst.setString(1, user);
+            final int id = authId.getAsInt();
-            try (ResultSet rs = pst.executeQuery()) {
+            // Insert password in the correct table
-                if (rs.next()) {
+            String sql = "UPDATE " + xfPrefix + "user_authenticate SET data=? WHERE " + col.ID + "=?;";
-                    int id = rs.getInt(col.ID);
+            try (PreparedStatement pst = con.prepareStatement(sql)) {
-                    // Insert password in the correct table
+                String serializedHash = XfBCrypt.serializeHash(password.getHash());
-                    // TODO #1255: Close these statements with try-catch
+                byte[] bytes = serializedHash.getBytes();
-                    sql = "UPDATE " + xfPrefix + "user_authenticate SET data=? WHERE " + col.ID + "=?;";
+                Blob blob = con.createBlob();
-                    PreparedStatement pst2 = con.prepareStatement(sql);
+                blob.setBytes(1, bytes);
-                    String serializedHash = XfBCrypt.serializeHash(password.getHash());
+                pst.setBlob(1, blob);
-                    byte[] bytes = serializedHash.getBytes();
+                pst.setInt(2, id);
-                    Blob blob = con.createBlob();
+                pst.executeUpdate();
-                    blob.setBytes(1, bytes);
+            }
-                    pst2.setBlob(1, blob);
+
-                    pst2.setInt(2, id);
+            // ...
-                    pst2.executeUpdate();
+            sql = "UPDATE " + xfPrefix + "user_authenticate SET scheme_class=? WHERE " + col.ID + "=?;";
-                    pst2.close();
+            try (PreparedStatement pst = con.prepareStatement(sql)) {
-                    // ...
+                pst.setString(1, XfBCrypt.SCHEME_CLASS);
-                    sql = "UPDATE " + xfPrefix + "user_authenticate SET scheme_class=? WHERE " + col.ID + "=?;";
+                pst.setInt(2, id);
-                    pst2 = con.prepareStatement(sql);
+                pst.executeUpdate();
-                    pst2.setString(1, XfBCrypt.SCHEME_CLASS);
-                    pst2.setInt(2, id);
-                    pst2.executeUpdate();
-                    pst2.close();
-                }
             }
         }
     }
 
     @Override
     public void removeAuth(String user, Connection con) throws SQLException {
-        String sql = "SELECT " + col.ID + " FROM " + tableName + " WHERE " + col.NAME + "=?;";
+        OptionalInt authId = retrieveIdFromTable(user, con);
-        try (PreparedStatement xfSelect = con.prepareStatement(sql)) {
+        if (authId.isPresent()) {
-            xfSelect.setString(1, user);
+            String sql = "DELETE FROM " + xfPrefix + "user_authenticate WHERE " + col.ID + "=?;";
-            try (ResultSet rs = xfSelect.executeQuery()) {
+            try (PreparedStatement xfDelete = con.prepareStatement(sql)) {
-                if (rs.next()) {
+                xfDelete.setInt(1, authId.getAsInt());
-                    int id = rs.getInt(col.ID);
+                xfDelete.executeUpdate();
-                    sql = "DELETE FROM " + xfPrefix + "user_authenticate WHERE " + col.ID + "=?;";
-                    try (PreparedStatement xfDelete = con.prepareStatement(sql)) {
-                        xfDelete.setInt(1, id);
-                        xfDelete.executeUpdate();
-                    }
-                }
             }
         }
     }

src/test/java/fr/xephi/authme/ClassesConsistencyTest.java

@@ -5,6 +5,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import fr.xephi.authme.datasource.Columns;
+import fr.xephi.authme.datasource.mysqlextensions.MySqlExtension;
 import fr.xephi.authme.initialization.HasCleanup;
 import fr.xephi.authme.process.register.executors.RegistrationMethod;
 import fr.xephi.authme.security.crypts.Whirlpool;
@@ -55,6 +56,7 @@ public class ClassesConsistencyTest {
     /** Classes excluded from the field visibility test. */
     private static final Set<Class<?>> CLASSES_EXCLUDED_FROM_VISIBILITY_TEST = ImmutableSet.of(
         Whirlpool.class, // not our implementation, so we don't touch it
+        MySqlExtension.class, // has immutable protected fields used by all children
         Columns.class // uses non-static String constants, which is safe
     );