Package software.xdev.micromigration.migrater

Class AbstractMigrater

java.lang.Object

software.xdev.micromigration.migrater.AbstractMigrater

All Implemented Interfaces:

MicroMigrater

Direct Known Subclasses:

ExplicitMigrater

public abstract class AbstractMigrater
extends java.lang.Object
implements MicroMigrater

Provides the basic functionality to apply VersionAgnosticMigrationScripts to a datastore.

Author:

Johannes Rabauer

Constructor Summary

Constructors

Constructor	Description
AbstractMigrater()

Method Summary

Modifier and Type	Method	Description
protected void	checkIfVersionIsAlreadyRegistered(VersionAgnosticMigrationScript<?,?> scriptToCheck)	Checks if the given VersionAgnosticMigrationScript is not already registered in the MicroMigrater.getSortedScripts().
<E extends VersionAgnosticMigrationEmbeddedStorageManager<?,?>> MigrationVersion	migrateToNewest(MigrationVersion fromVersion, E storageManager, java.lang.Object root)	Executes all the scripts that are available to the migrater.
<E extends VersionAgnosticMigrationEmbeddedStorageManager<?,?>> MigrationVersion	migrateToVersion(MigrationVersion fromVersion, MigrationVersion targetVersion, E storageManager, java.lang.Object objectToMigrate)	Executes all the scripts that are available to the migrater until the given targetVersion is reached.
void	registerNotificationConsumer(java.util.function.Consumer<ScriptExecutionNotificationWithScriptReference> notificationConsumer)	Registers a callback to take action when a script is executed.
AbstractMigrater	withClock(java.time.Clock clock)	Change used clock for notifications from registerNotificationConsumer(Consumer).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface software.xdev.micromigration.migrater.MicroMigrater

getSortedScripts

Constructor Detail

AbstractMigrater

public AbstractMigrater()

Method Detail

registerNotificationConsumer

public void registerNotificationConsumer(java.util.function.Consumer<ScriptExecutionNotificationWithScriptReference> notificationConsumer)

Description copied from interface: MicroMigrater

Registers a callback to take action when a script is executed.

Specified by:

registerNotificationConsumer in interface MicroMigrater

Parameters:

notificationConsumer - is executed when a script is used from this migrater.

migrateToNewest

public <E extends VersionAgnosticMigrationEmbeddedStorageManager<?,?>> MigrationVersion migrateToNewest(MigrationVersion fromVersion,
                                                                                                              E storageManager,
                                                                                                              java.lang.Object root)

Description copied from interface: MicroMigrater

Executes all the scripts that are available to the migrater. Only scripts with a higher target version than the given fromVersion are executed.
Scripts are executed one after another from the lowest to the highest version.

Example:
Current version is 1.0.0
Scripts for v1.1.0, v2.0.0 and v1.2.1 are available
Scripts are chain executed like v1.1.0 then v1.2.1 then v2.0.0

Specified by:

migrateToNewest in interface MicroMigrater

Type Parameters:

E - the VersionAgnosticMigrationEmbeddedStorageManager which contains the migrating object

Parameters:

fromVersion - is the current version of the datastore. Scripts for lower versions then the fromVersion are not executed.

storageManager - is relayed to the scripts VersionAgnosticMigrationScript.migrate(Context) method. This way the script can call VersionAgnosticMigrationEmbeddedStorageManager.store(Object) or another method on the storage manager.

root - is relayed to the scripts VersionAgnosticMigrationScript.migrate(Context) method. This way the script can change something within the root object.

Returns:

the target version of the last executed script

migrateToVersion

public <E extends VersionAgnosticMigrationEmbeddedStorageManager<?,?>> MigrationVersion migrateToVersion(MigrationVersion fromVersion,
                                                                                                               MigrationVersion targetVersion,
                                                                                                               E storageManager,
                                                                                                               java.lang.Object objectToMigrate)

Description copied from interface: MicroMigrater

Executes all the scripts that are available to the migrater until the given targetVersion is reached. Only scripts with a higher target version than the given fromVersion are executed.
Scripts are executed one after another from the lowest to the highest version.

Example:
Current version is 1.0.0
Scripts for v1.1.0, v2.0.0 and v1.2.1 are available
Scripts are chain executed like v1.1.0 then v1.2.1 then v2.0.0

Specified by:

migrateToVersion in interface MicroMigrater

Type Parameters:

E - the VersionAgnosticMigrationEmbeddedStorageManager which contains the migrating object

Parameters:

fromVersion - is the current version of the datastore. Scripts for lower versions then the fromVersion are not executed.

targetVersion - is the highest allowed script version. Scripts which have a higher version won't be exectued.

storageManager - is relayed to the scripts VersionAgnosticMigrationScript.migrate(Context) method. This way the script can call EmbeddedStorageManager#store or another method on the storage manager.

objectToMigrate - is relayed to the scripts VersionAgnosticMigrationScript.migrate(Context) method. This way the script can change something within the object to migrate.

Returns:

the target version of the last executed script

checkIfVersionIsAlreadyRegistered

protected void checkIfVersionIsAlreadyRegistered(VersionAgnosticMigrationScript<?,?> scriptToCheck)

Checks if the given VersionAgnosticMigrationScript is not already registered in the MicroMigrater.getSortedScripts().

Parameters:

scriptToCheck - It's target version is checked, if it is not already registered.

Throws:

VersionAlreadyRegisteredException - if script is already registered.

withClock

public AbstractMigrater withClock(java.time.Clock clock)

Change used clock for notifications from registerNotificationConsumer(Consumer).

Parameters:

clock - is used when a ScriptExecutionNotificationWithoutScriptReference is created

Returns:

self