org.apache.sling.installer.api.OsgiInstaller Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sling.installer.api;
import org.osgi.annotation.versioning.ProviderType;
/**
* Service for installing/updating/removing installable resources
* {@link InstallableResource} in an OSGi framework.
*
* The resources are provided by provider components which are
* clients of this API. For example a file directory provider might
* scan a directory in the file system and provide the artifacts
* contained in the configured directory.
*
* When such a client starts it should first call
* {@link #registerResources(String, InstallableResource[])} and
* inform this service about all available resources. In the case
* of a file directory provider, this list would contain all
* files found in the directory (and sub directories). This is
* the rendezvous point. The OSGi installer service compares this
* complete list with previous lists it might have and triggers
* corresponding tasks like installing new artifacts and
* uninstalling removed artifacts.
*
* Once this rendezvous has been done between a client and the
* OSGi installe, the client calls
* {@link #updateResources(String, InstallableResource[], String[])}
* to inform about changes like new resources or removed resources.
*
* A single provider should never call these methods in parallel,
* before calling any method a previous call must have finished!
*
* The OSGi installer detects the resources and based on their type
* and metadata, the installer decides whether to install them,
* update an already installed artifact or simply ignore them.
* For example, for bundles the symbolic name and the version is used.
*/
@ProviderType
public interface OsgiInstaller {
/**
* Provide the installer with the complete list of installable
* resources for a given client.
*
* Client must call this at startup and/or when the installer
* service becomes available. The installer stores the list of
* previously registered/added resources, compares with the new
* list and removes resources that have disappeared.
*
* Invalid resources are ignored.
*
* @param urlScheme identifies the client.
* @param resources the list of available resources
*/
void registerResources(String urlScheme, InstallableResource[] resources);
/**
* Inform the installer that resources are available for installation
* and/or other resources are no longer available.
* This method is called if
* - installed resources have been modified
* - new resources are available
* - installed resources should be uninstalled
* Invalid resources are ignored.
* @param urlScheme identifies the client.
* @param resources An array of updated/new resources - might be null
* @param ids An array of identifiers for removed resources - might be null
*/
void updateResources(String urlScheme, InstallableResource[] resources,
String[] ids);
}