package er.extensions.migration;
import java.io.UnsupportedEncodingException;
import org.apache.log4j.Logger;
import com.webobjects.eoaccess.EOAdaptorChannel;
import com.webobjects.eoaccess.EOModel;
import com.webobjects.eocontrol.EOEditingContext;
import com.webobjects.foundation.NSArray;
import com.webobjects.foundation.NSBundle;
import com.webobjects.foundation._NSStringUtilities;
import er.extensions.foundation.ERXProperties;
import er.extensions.jdbc.ERXJDBCUtilities;
/**
* <p>Convenience superclass for Migration classes. Checks for corresponding sql files name
* "ClassnameX_Upgrade.migration" and "ClassnameX_Downgrade.migration" where
* "Classname" is the classname of the migration class. The files have to to be
* in a corresponding bundle. Implement "migrationBundleName" to return the
* correct name of the bundle.</p>
*
* <p>This makes migrations easier as you only have to create a new Java class according to the
* migration naming conventions, inherit from this class and put your SQL in a properly
* named text file (or more than one file, if you use database specific migrations).</p>
*
* <p>If you need database specific migrations use:
*
* <blockquote><code>er.extensions.migration.ERXMigration.useDatabaseSpecificMigrations=true</code></blockquote>
*
* in your Properties. The default is not to use database specific migrations. A filename
* for a database specific migration is then, for example, <code>ClassnameX_FrontBase_Upgrade.migration</code> or
* <code>ClassnameX_Postgresql_Upgrade.migration</code>.
*
* <p>For the database specific part of the filename, the databaseProductName as from the JDBC
* adaptor is used. So make sure, you're using the correct filename. The migration will throw
* an exception if the appropriate migration textfile can't be found.</p>
*
* @author cug
*/
public abstract class ERXMigration implements IERXMigration {
/**
* Logging support
*/
private Logger log = Logger.getLogger(ERXMigration.class.getName());
private Boolean _useDatabaseSpecificMigrations;
/**
* Override the global application preference on per-database migrations.
*
* @param useDatabaseSpecificMigrations if true, database-specific migrations will be used
*/
public ERXMigration(boolean useDatabaseSpecificMigrations) {
_useDatabaseSpecificMigrations = Boolean.valueOf(useDatabaseSpecificMigrations);
}
public ERXMigration() {
}
/**
* No dependencies
*/
public NSArray<ERXModelVersion> modelDependencies() {
return null;
}
/**
* Checks for a corresponding downgrade file which is performed as a raw SQL action
*/
public void downgrade(EOEditingContext editingContext, EOAdaptorChannel channel, EOModel model) throws Throwable {
String sqlString = null;
if (useDatabaseSpecificMigrations()) {
sqlString = getSQLForMigration(getClass().getSimpleName() + "_" + ERXJDBCUtilities.databaseProductName(channel) + "_Downgrade.migration");
}
else {
sqlString = getSQLForMigration(getClass().getSimpleName() + "_Downgrade.migration");
}
if (sqlString != null) {
log.info("Applying migration for: " + getClass().getName());
ERXJDBCUtilities.executeUpdateScript(channel, sqlString);
}
else {
if (useDatabaseSpecificMigrations()) {
throw new ERXMigrationFailedException("No downgrade for migration: " + getClass().getName() + "found for database: " + ERXJDBCUtilities.databaseProductName(channel));
}
throw new ERXMigrationFailedException("No downgrade for migration: " + getClass().getName());
}
}
/**
* Checks for a corresponding upgrade file which is performed as a raw SQL action
*/
public void upgrade(EOEditingContext editingContext, EOAdaptorChannel channel, EOModel model) throws Throwable {
String sqlString = null;
if (useDatabaseSpecificMigrations()) {
sqlString = getSQLForMigration(getClass().getSimpleName() + "_" + ERXJDBCUtilities.databaseProductName(channel) + "_Upgrade.migration");
}
else {
sqlString = getSQLForMigration(getClass().getSimpleName() + "_Upgrade.migration");
}
if (sqlString != null) {
log.info("Applying migration for: " + getClass().getName());
ERXJDBCUtilities.executeUpdateScript(channel, sqlString);
}
else {
if (useDatabaseSpecificMigrations()) {
throw new ERXMigrationFailedException("No upgrade for migration: " + getClass().getName() + " found for database: " + ERXJDBCUtilities.databaseProductName(channel));
}
throw new ERXMigrationFailedException("No upgrade for migration: " + getClass().getName() + " found.");
}
}
/**
* Checks in the current bundle for migration files corresponding to this classes name
*
* @param migrationName
* @return SQL string
*/
protected String getSQLForMigration(String migrationName) {
NSBundle bundle;
String migrationBundleName = migrationBundleName();
if (migrationBundleName == null) {
bundle = NSBundle.bundleForClass(getClass());
}
else {
bundle = NSBundle.bundleForName(migrationBundleName());
if (bundle == null) {
bundle = NSBundle._appBundleForName(migrationBundleName());
}
}
NSArray<String> resourcePaths = bundle.resourcePathsForResources("migration", null);
if (resourcePaths != null) {
for (String currentPath : resourcePaths) {
if (currentPath.endsWith(migrationName)) {
try {
return new String(bundle.bytesForResourcePath(currentPath), _NSStringUtilities.UTF8_ENCODING);
}
catch (UnsupportedEncodingException e) {
log.error(e, e);
}
}
}
}
return null;
}
/**
* The name to create the NSBundle for the current bundle, defaults to the
* bundle that contains the migration class.
*
* @return <code>null</code>
*/
protected String migrationBundleName() {
return null;
}
protected boolean useDatabaseSpecificMigrations() {
if (_useDatabaseSpecificMigrations == null) {
_useDatabaseSpecificMigrations = Boolean.valueOf(
ERXProperties.booleanForKeyWithDefault("er.extensions.migration.ERXMigration.useDatabaseSpecificMigrations", false));
}
return _useDatabaseSpecificMigrations.booleanValue();
}
}