Programming WebLogic Deployment
Understanding the WebLogic Deployment API
The WebLogic Deployment API implements and extends the J2EE Deployment API standard (JSR-88) interfaces to provide specific deployment functionality for WebLogic Server applications. The following sections describe the structure and functionality of the WebLogic Deployment API:
- The WebLogic Deployment API
- J2EE Deployment API Compliance
- WebLogic Server Value-Added Deployment Features
- The service provider Interface Package
- The Model Package
- The Shared Package
- The Tools Package
The WebLogic Deployment API
WebLogic Server 9.0 deprecates the use of the weblogic.management.deploy API used in earlier releases.
The following sections provide an overview of the WebLogic Server Deployment API:
- WebLogic Deployment API Deployment Phases
- weblogic.Deployer Implementation of the WebLogic Deployment API
- When to Use the WebLogic Deployment API
WebLogic Deployment API Deployment Phases
The J2EE Deployment API standard (JSR-88) differentiates between a configuration session and deployment. They are distinguished as follows:
- Application Configuration which involves the generation of descriptors for a deployment plan
- Deployment tasks such as Distributing, Starting, Stopping, Redeploying, Undeploying
In order to effectively manage the deployment process in your environment, use the WebLogic Deployment API to:
Configure an Application for Deployment
In this document, the term configuration refers to the process of preparing an application or deployable resource for deployment to a WebLogic Server instance. Configuring an application consists of the following phases:
- Application Evaluation—Inspection and evaluation of application files to determine the structure of the application and content of the embedded descriptors. See Application Evaluation.
- Front-end Configuration—Creation of configuration information based on content embedded within the application. This content may be in the form of WebLogic Server descriptors, defaults, and user provided deployment plans. See Perform Front-end Configuration.
- Deployment Configuration—Modification of individual WebLogic Server configuration values based on user inputs and the selected WebLogic Server targets. See Customizing Deployment Configuration.
- Deployment preparation—Generation of the final deployment plan and preliminary client-side validation of the application. See Deployment Preparation.
Deploy an Application
Application deployment is the process of distributing an application and plan to the administration server for server-side processing and application startup. See Performing Deployment Operations.
weblogic.Deployer Implementation of the WebLogic Deployment API
WebLogic Server provides a packaged deployment tool, webLogic.Deployer, to provide deployment services for WebLogic Server. Any deployment operation that can be implemented using the WebLogic Deployment API is implemented, either in part or in full, by webLogic.Deployer.
When to Use the WebLogic Deployment API
webLogic.Deployer is the recommended deployment tool for the WebLogic Server Environment. See Deploying Applications to the WebLogic Server for information on how to use webLogic.Deployer and the WebLogic Server Administration Console.
You may need to implement the WebLogic Deployment API in the following cases:
- You need to model your own implementation and interface with the WebLogic service provider Interface (SPI). In this case, the WebLogic Deployment API deployment factory is used to obtain a WebLogicDeploymentManager, which extends javax.enterprise.deploy.spi.DeploymentManager for use with the weblogic.deploy.api.spi. See Application Evaluation and the J2EE Deployment API standard.
- You need to create your own deployment interface instead using the WebLogic Server Administration Console and/or webLogic.Deployer. In this case, you may implement some or all WebLogic Deployment API Deployment Phases using the WebLogic Deployment API classes and interfaces.
J2EE Deployment API Compliance
The WebLogic Deployment API classes and interfaces extend and implement the J2EE Deployment API standard (JSR-88) interfaces, which are described in the javax.enterprise.deploy sub-packages. The WebLogic Deployment API provides the following packages:
- weblogic.deploy.api.spi
- weblogic.deploy.api.spi.factories
- weblogic.deploy.api.model
- weblogic.deploy.api.shared
- weblogic.deploy.api.tools
WebLogic Server Value-Added Deployment Features
WebLogic supports the “Product Provider” role described in the J2EE Deployment API standard (JSR-88) and provides utilities specific to the WebLogic Server environment in addition to extensible components for any J2EE network client. These extended features include:
- Support for WebLogic features, such as starting in admin mode or redeploying with versioning.
- Fine grain control, such as:
- module level targeting
- Partial Redeployment, the redeployment or removal of parts of an application.
- Dynamic configuration changes.
- Support of WebLogic module extensions such as JMS, JDBC, Interception, and Application Specific Configuration (Custom/Configuration) modules.
- Additional operations, such as the Deploy verb which combines distribute and start.
The WebLogic Deployment API does not support an automated fallback procedure for a failed application update. The policy and procedures for this behavior must be defined and configured by the developers and administrators for each deployment environment.
The service provider Interface Package
As a J2EE product provider, Oracle extends the Sun Microsystems javax service provider Interface (SPI) package to provide specific configuration and deployment control for WebLogic Server. The core interface for this package is the DeploymentManager, from which all other deployment activities are initiated, monitored, and controlled.
The WebLogicDeploymentManager interface provides WebLogic Server extensions to the javax.enterprise.deploy.spi.DeploymentManager interface. A WebLogicDeploymentManager object is a stateless interface for the Weblogic Server deployment framework. It provides basic deployment features as well as extended WebLogic Server deployment features such as production redeployment and partial deployment for modules in an Enterprise Application. You generally acquire a WebLogicDeploymentManager object using SessionHelper.getDeploymentManager method from the SessionHelper helper class from the Tools package. See Application Evaluation.
The following sections provide basic information on the functionality of the WebLogic Server SPI:
- weblogic.deploy.api.spi
- weblogic.deploy.api.spi.factories
- Module Targeting
- Support for Querying WebLogic Target Types
- Server Staging Modes
- DConfigBean Validation
weblogic.deploy.api.spi
The weblogic.deploy.api.spi package provides the interfaces required to configure and deploy applications to a target (see Support for Querying WebLogic Target Types for valid target types). This package enables you to create deployment tools that can implement a WebLogic Server-specific deployment configuration for an Enterprise Application or stand-alone module.
weblogic.deploy.api.spi includes the WebLogicDeploymentManager interface. Use this deployment manager to perform all deployment-related operations such as distributing, starting, and stopping applications in WebLogic Server. The WebLogicDeploymentManager also provides important extensions to the J2EE DeploymentManager interface for features such as module-level targeting for Enterprise Application modules, production redeployment, application versioning, application staging modes, and constraints on Administrative access to deployed applications.
The WebLogicDeploymentConfiguration and WebLogicDConfigBean classes in the weblogic.deploy.api.spi package represent the deployment and configuration descriptors (WebLogic Server deployment descriptors) for an application.
- A WebLogicDeploymentConfiguration object is a wrapper for a deployment plan.
- A WebLogicDConfigBean encapsulates the properties in Weblogic deployment descriptors.
weblogic.deploy.api.spi.factories
This package contains only one interface, the WebLogicDeploymentFactory. This is a WebLogic extension to javax.enterprise.deploy.spi.factories.DeploymentFactory. Use this factory interface to select and allocate DeploymentManager objects that have different characteristics. The WebLogicDeploymentManager characteristics are defined by public fields in the WebLogicDeploymentFactory.
Module Targeting
Module targeting is deploying specific modules in an application to different targets as opposed to deploying all modules to the same set of targets as specified by JSR-88. Module targeting is supported by the WebLogicDeploymentManager.createTargetModuleID methods.
The WebLogicTargetModuleID class contains the WebLogic Server extensions to the javax.enterprise.deploy.spi.TargetModuleID interface. This class is closely related to the configured TargetInfoMBeans (AppDeploymentMBean and SubDeploymentMBean). The WebLogicTargetModuleID class provides more detailed descriptions of the application modules and their relationship to targets than those in TargetInfoMBeans. See Target Objects.
Support for Querying WebLogic Target Types
For WebLogic Server, the WebLogicTarget class provides a direct interface for maintaining the target types available to WebLogic Server. Target accessor methods are described in Table 2-1.
Server Staging Modes
The staging mode of an application affects its deployment behavior. The application's staging behavior is set using DeploymentOptions.setStageMode(stage mode) where the value of stage mode is one of the following:
- STAGE—Force copying of files to target servers.
- NO_STAGE—Files are not copied to target servers.
- EXTERNAL_STAGE—Files are staged manually.
DConfigBean Validation
The property setters in a DConfigBean reject attempts to set invalid values. This includes property type validation such as attempting to set an integer property to a non-numeric value. Some properties perform semantic validations, such as ensuring a maximum value is not smaller than its associated minimum value.
The Model Package
These classes are the WebLogic Server extensions to and implementations of the javax.enterprise.deploy.model interfaces. The model interfaces describes the standard elements, such as deployment descriptors, of a J2EE application.
weblogic.deploy.api.model
This package contains the interfaces used to represent the J2EE configuration of a deployable object. A deployable object is a deployment container for an Enterprise Application or standalone module.
The WebLogic Server implementation of the javax.enterprise.deploy.model interfaces enable you to work with applications that are stored in a WebLogic Server application installation directory, a formal directory structure used for managing application deployment files, deployments, and external WebLogic Deployment descriptors generated during the configuration process. See Preparing Applications and Modules for Deployment for more information about the layout of an application installation directory. It supports any J2EE application, with extensions to support applications residing in an application installation directory.
weblogic.deploy.api.model does not support dynamic changes to J2EE deployment descriptor elements during configuration and therefore does not support registration and removal of Xpath listeners. DDBean.addXPathListener and removeXPathListener are not supported.
The WebLogicDeployableObject class and WebLogicDDBean interface in the weblogic.deploy.api.model package represent the standard deployment descriptors in an application.
Accessing Deployment Descriptors
J2EE Deployment API dictates that J2EE deployment descriptors be accessed through a DeployableObject. A DeployableObject represents a module in an application. Elements in the descriptors are represented by DDBeans, one for each element in a deployment descriptor. The root element of a descriptor is represented by a DDBeanRoot object. All of these interfaces are implemented in corresponding interfaces and classes in this package.
The WebLogicDeployableObject class, which is the Weblogic Server implementation of DeployableObject, provides the createDeployableObject methods, which create the WebLogicDeployableObject and WebLogicDDBean for the application's deployment descriptors. Basic configuration tasks are accomplished by associating the WebLogicDDBean with a WebLogicDConfigBean, which represent the server configuration properties required for deploying the application on a WebLogic Server. See Application Evaluation.
Unlike a DConfigbean, which contain configuration information specifically for a server environment (in this case WebLogic server instance), a DDBean object takes in the general deployment descriptor elements for the application. For example, if you were deploying a Web application, the deployment descriptors in WebLogicDDBeans come from WEB-INF/web.xml file in the .war archive. The information for the WebLogicDConfigBeans would come from WEB-INF/weblogic.xml in the .war archive based on the WebLogicDDBeans. Though they serve the same fundamental purpose of holding configuration information, they are logically separate as a DDBean describes the application while a DConfigBeans configures the application for a specific environment.
Both of these objects are generated during the initiation of a configuration session. The WebLogicDeployableObject, WebLogicDDBeans, and WebLogicDConfigBeans are all instantiated and manipulated in a configuration session. See Overview of the Configuration Process.
The Shared Package
The following sections provide information on classes that represent WebLogic Server-specific deployment commands, module types, and target types as classes:
- weblogic.deploy.api.shared
- Command Types for Deploy and Update
- Support for Module Types
- Support for all WebLogic Server Target Types
weblogic.deploy.api.shared
The weblogic.deploy.api.shared package provides classes that represent the WebLogic Server-specific deployment commands, module types, and target types as classes. These objects can be shared by weblogic.deploy.api.model and weblogic.deploy.api.spi packages.
The definitions of the standard javax.enterprise.deploy.shared classes ModuleType and CommandType are extended to provide support for:
- The module type, see Support for Module Types
- Commands, see Command Types for Deploy and Update
The WebLogicTargetType class, which is not required by the J2EE Deployment API standard (JSR-88), enumerates the different types of deployment targets supported by WebLogic Server. This class does not extend a javax deployment class. See Support for all WebLogic Server Target Types.
Command Types for Deploy and Update
The deploy and update command types are added to the required command types defined in the javax.enterprise.spi.shared package and are available to a WebLogicDeploymentManager.
Support for Module Types
Supported module types include JMS, JDBC, Interception, WSEE, Config, and WLDF. These are defined in the weblogic.deploy.api.shared.WebLogicModuleType class as fields.
Support for all WebLogic Server Target Types
Targets, which were not implemented in the J2EE Deployment API specification, are implemented in the WebLogic Deployment API. The valid target values are:
- Cluster
- JMS Server
- SAF (Store-and-Forward) Agent
- Server
- Virtual Host
These are enumerated field values in the weblogic.deploy.api.shared.WebLogicTargetType class.
The Tools Package
The following sections provide information on API tools you can use to perform common deployment tool tasks with a minimum of number of controls and explicit object manipulations:
weblogic.deploy.api.tools
The weblogic.deploy.api.tools package provides convenience classes that can help you:
- Obtain a WebLogicDeploymentManager
- Populate a configuration for an application
- Create a new or updated deployment plan
The classes in the tools package are not extensions of the J2EE Deployment API standard (JSR-88) interfaces. They provide easy access to deployment operations provided by the WebLogic Deployment API.
SessionHelper
Although configuration sessions can be controlled from a WebLogicDeploymentManager directly, SessionHelper provides simplified methods. If your tools code directly to WebLogic Server's J2EE Deployment API implementation, you should always use SessionHelper.
Use SessionHelper to obtain a WebLogicDeploymentManager with one method call. To do this effectively, it must be able to locate the application. The SessionHelper views an application and deployment plan artifacts using an “install root” abstraction, which ideally is the actual organization of the application. The install root appears as follows:
install-root (eg myapp)-- app----- archive (eg myapp.ear)-- plan----- deployment plan (eg plan.xml)----- external descriptors (eg META-INF/weblogic-application.xml...)There is no requirement to mandate that this structure be used for applications. It is a preferred approach because it serves to keep the application and its configuration artifacts under a common root and provides SessionHelper with a format it can interpret.
SessionHelper.getModuleInfo() returns an object that is useful for understanding the structure of an application without having to work directly with DDBeans and DeployableObjects. It provides such information as
- Names and types of modules and submodules in the application
- Names of web services provided by the application
- Context roots for web applications
- Names of enterprise beans in an EJB
Internally, the deployment descriptors are represented as descriptor bean trees and trees of typed Java Bean objects that represent the individual descriptor elements. These bean trees are easier to work with than the more generic DDBean and DConfigBean objects. The descriptor bean trees for each module are directly accessible from the associated WebLogicDDBeanRoot and WebLogicDConfigBeanRoot objects for each module using their getDescriptorBean methods. Modifying the bean trees obtained from a WebLogicDConfigBean has the same effect as modifying the associated DConfigBean, and therefore the application's deployment plan.
Deployment Plan Creation
weblogic.PlanGenerator creates a deployment plan template based on the J2EE and WebLogic Server descriptors included in an application. The resulting plan describes the application structure, identifies all deployment descriptors, and exports a subset of the application's configurable properties. Export properties to expose them to tools like the WebLogic Server console which then uses the plan to assist the administrator in providing appropriate values for those properties. By default, the weblogic.PlanGenerator tool only exports application dependencies; those properties required for a successful deployment. This behavior can be overridden using of the following options:
- Dependencies: Export resources referenced by the application (default)
- Declarations: Export resources defined by the application
- Configurables: Export non-resource oriented configurable properties
- Dynamics: Export properties that may be changed in a running application
- All: Export all changeable properties
- None: Export no properties