Term
| You want centralized, common processing across requests, such as checking the data-encoding scheme of each request, logging information about each request, or compressing an outgoing response |
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Definition
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Term
| You want pre and postprocessing components loosely coupled with core request-handling services to facilitate unobtrusive addition and removal. |
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Definition
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Term
| * You want pre and postprocessing components independent of each other and self contained to facilitate reuse. |
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Definition
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Term
Centralizes control (FC)
Loosely coupled (use the deployment descriptor to add and remove)
Reusable |
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Definition
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Term
Declarative and flexible configuration
Information sharing is inefficient
Related Patterns
Front Controller |
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Definition
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Term
| * You want to avoid duplicate control logic. |
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Definition
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Term
You want to apply common logic to multiple requests.
You want to separate system processing logic from the view
You want to centralize controlled access points into your system |
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Definition
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Term
Centralizes control (IF)
Improves reusability |
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Definition
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Term
| You want to keep Views/presentation, Controls/business logic, and Models/data access separate. |
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Definition
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Term
Allows multiple view types for the same info
Decouples presentation, business logic, and data access components |
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Definition
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Term
* You want clients to access components in other tiers to retrieve and update data.
* You want to reduce remote requests across the network. |
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Definition
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Term
Reduces network traffic
Simplifies remote object and remote interface
Introduces stale transfer objects and concurrency issues
Reduces coupling between presentation and business tiers (BD, SL) |
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Definition
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Term
| * You want to hide the details of service creation, reconfiguration, and invocation retries from the clients. |
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Definition
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Term
* You want to minimize coupling between clients and the business services, thus hiding the underlying implementation details of the service, such as lookup and access.
* You want to translate network exceptions into application or user exceptions. |
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Definition
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Term
Reduces coupling between presentation and business tiers (TO, SL)
Translates business service exceptions
Exposes a simpler, uniform interface to the business tier
Introduces an additional layer
Hides remoteness |
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Definition
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Term
| * You want to use the JNDI API to look up and use business components, such as enterprise beans and JMS components, and services such as data sources. |
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Definition
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Term
| * You want to centralize and reuse the implementation of lookup mechanisms for J2EE application clients. |
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Definition
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Term
* You want to avoid performance overhead related to initial context creation and service lookups.
* You want to reestablish a connection to a previously accessed enterprise bean instance, using its Handle object. |
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Definition
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Term
Provides uniform service access to clients
Reduces coupling between presentation and business tiers (TO, BD)
Improves client performance by caching service handles |
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Definition
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