REPO-4180: Service Pack: MNT-20305 Oracle schema validation check failure with ojdbc7.jar version 12.1.0.2

- fixed regression in SchemaBootstrap that cause the schema validation to not be done
   - added support for custom sequences retrieval (active if only schema reference sequences file exists)
   - added dialect and script utility classes
   - refactored ExportDb, ScriptExecutorImpl and SchemaBootstrap to use the utility classes to reduce code duplication

src/main/java/org/alfresco/util/DBScriptUtil.java

@@ -0,0 +1,107 @@
+/*
+ * #%L
+ * Alfresco Repository
+ * %%
+ * Copyright (C) 2005 - 2019 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.util;
+
+import java.io.IOException;
+import java.io.LineNumberReader;
+
+import org.springframework.core.io.support.EncodedResource;
+
+public abstract class DBScriptUtil
+{
+    private static final String DEFAULT_SCRIPT_COMMENT_PREFIX = "--";
+
+    /**
+     * Read a script from the provided EncodedResource and build a String containing
+     * the lines.
+     *
+     * @param resource
+     *            the resource (potentially associated with a specific encoding) to
+     *            load the SQL script from
+     * @return a String containing the script lines
+     */
+    public static String readScript(EncodedResource resource) throws IOException
+    {
+        return readScript(resource, DEFAULT_SCRIPT_COMMENT_PREFIX);
+    }
+
+    /**
+     * Read a script from the provided EncodedResource, using the supplied line
+     * comment prefix, and build a String containing the lines.
+     *
+     * @param resource
+     *            the resource (potentially associated with a specific encoding) to
+     *            load the SQL script from
+     * @param lineCommentPrefix
+     *            the prefix that identifies comments in the SQL script (typically
+     *            "--")
+     * @return a String containing the script lines
+     */
+    private static String readScript(EncodedResource resource, String lineCommentPrefix) throws IOException
+    {
+        LineNumberReader lineNumberReader = new LineNumberReader(resource.getReader());
+        try
+        {
+            return readScript(lineNumberReader, lineCommentPrefix);
+        }
+        finally
+        {
+            lineNumberReader.close();
+        }
+    }
+
+    /**
+     * Read a script from the provided LineNumberReader, using the supplied line
+     * comment prefix, and build a String containing the lines.
+     *
+     * @param lineNumberReader
+     *            the LineNumberReader containing the script to be processed
+     * @param lineCommentPrefix
+     *            the prefix that identifies comments in the SQL script (typically
+     *            "--")
+     * @return a String containing the script lines
+     */
+    private static String readScript(LineNumberReader lineNumberReader, String lineCommentPrefix) throws IOException
+    {
+        String statement = lineNumberReader.readLine();
+        StringBuilder scriptBuilder = new StringBuilder();
+        while (statement != null)
+        {
+            if (lineCommentPrefix != null && !statement.startsWith(lineCommentPrefix))
+            {
+                if (scriptBuilder.length() > 0)
+                {
+                    scriptBuilder.append('\n');
+                }
+                scriptBuilder.append(statement);
+            }
+            statement = lineNumberReader.readLine();
+        }
+
+        return scriptBuilder.toString();
+    }
+
+}

src/main/java/org/alfresco/util/DialectUtil.java

@@ -0,0 +1,94 @@
+/*
+ * #%L
+ * Alfresco Repository
+ * %%
+ * Copyright (C) 2005 - 2019 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.util;
+
+import org.alfresco.repo.domain.dialect.Dialect;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.support.ResourcePatternResolver;
+
+public abstract class DialectUtil
+{
+    /** The placeholder for the configured <code>Dialect</code> class name: <b>${db.script.dialect}</b> */
+    public static final String PLACEHOLDER_DIALECT = "\\$\\{db\\.script\\.dialect\\}";
+
+    /**
+     * Replaces the dialect placeholder in the resource URL and attempts to find a
+     * file for it. If not found, the dialect hierarchy will be walked until a
+     * compatible resource is found. This makes it possible to have resources that
+     * are generic to all dialects.
+     *
+     * @return The Resource, otherwise null
+     */
+    public static Resource getDialectResource(ResourcePatternResolver resourcePatternResolver, Class<?> dialectClass, String resourceUrl)
+    {
+        // replace the dialect placeholder
+        String dialectResourceUrl = resolveDialectUrl(dialectClass, resourceUrl);
+        // get a handle on the resource
+        Resource resource = resourcePatternResolver.getResource(dialectResourceUrl);
+        if (!resource.exists())
+        {
+            // it wasn't found. Get the superclass of the dialect and try again
+            Class<?> superClass = dialectClass.getSuperclass();
+            if (Dialect.class.isAssignableFrom(superClass))
+            {
+                // we still have a Dialect - try again
+                return getDialectResource(resourcePatternResolver, superClass, resourceUrl);
+            }
+            else
+            {
+                // we have exhausted all options
+                return null;
+            }
+        }
+        else
+        {
+            // we have a handle to it
+            return resource;
+        }
+    }
+
+    /**
+     * Takes resource URL containing the {@link DialectUtil#PLACEHOLDER_DIALECT
+     * dialect placeholder text} and substitutes the placeholder with the name of
+     * the given dialect's class.
+     * <p/>
+     * For example:
+     * 
+     * <pre>
+     * resolveDialectUrl(MySQLInnoDBDialect.class, "classpath:alfresco/db/${db.script.dialect}/myfile.xml")
+     * </pre>
+     * 
+     * would give the following String:
+     * 
+     * <pre>
+     *   classpath:alfresco/db/org.hibernate.dialect.MySQLInnoDBDialect/myfile.xml
+     * </pre>
+     */
+    public static String resolveDialectUrl(Class<?> dialectClass, String resourceUrl)
+    {
+        return resourceUrl.replaceAll(PLACEHOLDER_DIALECT, dialectClass.getName());
+    }
+}