Object-oriented design anti-patterns
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The following are common object-oriented design anti-patterns: | The following are common object-oriented design anti-patterns: | ||
| − | *[[Anemic Domain Model]] - This anti-pattern occurs when data and | + | == Architecture Anti-patterns == |
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| + | *[[Anemic Domain Model]] - This anti-pattern occurs when data and behaviour is separated in the domain model. | ||
*[[BaseBean]] - This anti-pattern occurs when inheritance for implementation is used; that is a class inherits from another class not because it makes sense semantically but because it wants to use methods defined in the superclass. | *[[BaseBean]] - This anti-pattern occurs when inheritance for implementation is used; that is a class inherits from another class not because it makes sense semantically but because it wants to use methods defined in the superclass. | ||
| + | *[[Boat anchor]] - A piece of software or hardware in the system that serves no useful purpose. | ||
*[[Call super]] - This anti-pattern occurs when a superclass requires derived classes to call an overridden method. | *[[Call super]] - This anti-pattern occurs when a superclass requires derived classes to call an overridden method. | ||
*[[Circle-ellipse problem]] - This anti-pattern occurs when inheritance is not used correctly and the [[Liskov substitution principle]] is violated. | *[[Circle-ellipse problem]] - This anti-pattern occurs when inheritance is not used correctly and the [[Liskov substitution principle]] is violated. | ||
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*[[Functional decomposition]] - Classes that resemble the structure of programs creating using functional languages. | *[[Functional decomposition]] - Classes that resemble the structure of programs creating using functional languages. | ||
*[[God object]] - This anti-pattern occurs when an object / class does or knows too much. | *[[God object]] - This anti-pattern occurs when an object / class does or knows too much. | ||
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*[[Object cesspool]] - This anti-pattern occurs when an object pool is used incorrectly in that the state of objects is not reset when they are returned to the pool. | *[[Object cesspool]] - This anti-pattern occurs when an object pool is used incorrectly in that the state of objects is not reset when they are returned to the pool. | ||
*[[Object orgy]] - This anti-pattern occurs when objects access each other internals directly rather than going through methods. | *[[Object orgy]] - This anti-pattern occurs when objects access each other internals directly rather than going through methods. | ||
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*[[God object|The Blob]] - Equivalent to [[God object]], a very large class with a functional structure. | *[[God object|The Blob]] - Equivalent to [[God object]], a very large class with a functional structure. | ||
*[[Yo-yo problem]] - This problem occurs with deep inheritance hierarchies, where a programmer has to keep looking up and down the hierarchy to understand the flow of control of the program. | *[[Yo-yo problem]] - This problem occurs with deep inheritance hierarchies, where a programmer has to keep looking up and down the hierarchy to understand the flow of control of the program. | ||
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| + | == Development & Management Antipatterns == | ||
| + | *[[Lava Flow]] - Dead and forgotten code that hardens and becomes unchanged as the system develops. Requires a change in development strategy. | ||
| + | *[[Mushroom management]] - Separating developers from the end users. | ||
Many of these anti-patterns are closely related to common design maxims. | Many of these anti-patterns are closely related to common design maxims. | ||
Revision as of 08:11, 23 September 2009
Object-oriented design anti-patterns describe bad design solutions to common problems. As such, they are essentially the opposite of conventional design patterns.
The following are common object-oriented design anti-patterns:
Architecture Anti-patterns
- Anemic Domain Model - This anti-pattern occurs when data and behaviour is separated in the domain model.
- BaseBean - This anti-pattern occurs when inheritance for implementation is used; that is a class inherits from another class not because it makes sense semantically but because it wants to use methods defined in the superclass.
- Boat anchor - A piece of software or hardware in the system that serves no useful purpose.
- Call super - This anti-pattern occurs when a superclass requires derived classes to call an overridden method.
- Circle-ellipse problem - This anti-pattern occurs when inheritance is not used correctly and the Liskov substitution principle is violated.
- Circular dependency - This anti-pattern occurs when there are two or more modules that depend directly or indirectly on each other.
- Constant interface - This anti-pattern occurs when an interface is used to declare constants but does not contain any methods.
- Cut and paste programming - Code reused by copying source from other locations. Increasing the likelihood of errors and decreases maintainability.
- Functional decomposition - Classes that resemble the structure of programs creating using functional languages.
- God object - This anti-pattern occurs when an object / class does or knows too much.
- Object cesspool - This anti-pattern occurs when an object pool is used incorrectly in that the state of objects is not reset when they are returned to the pool.
- Object orgy - This anti-pattern occurs when objects access each other internals directly rather than going through methods.
- Poltergeists - This anti-pattern occurs when temporary objects are used to initialize or call methods on more permanent objects.
- Sequential coupling - This anti-pattern occurs when a class requires clients to call methods in a particular order.
- Spaghetti code - An adhoc structure that is difficult to extend and maintain.
- The Blob - Equivalent to God object, a very large class with a functional structure.
- Yo-yo problem - This problem occurs with deep inheritance hierarchies, where a programmer has to keep looking up and down the hierarchy to understand the flow of control of the program.
Development & Management Antipatterns
- Lava Flow - Dead and forgotten code that hardens and becomes unchanged as the system develops. Requires a change in development strategy.
- Mushroom management - Separating developers from the end users.
Many of these anti-patterns are closely related to common design maxims.
See also
| Design anti-patterns | |
|---|---|
|
Anemic Domain Model | BaseBean | Call super | Circle-ellipse problem | Circular dependency | |
