. The context used can refer to a software product, a software component
, asoftware architecture
, aframework, or even a class
in an object-oriented software environment. Finally, the object-oriented environment also knows a design pattern
, which is called wrapper pattern as well as sometimes adapter pattern
Inconsistencies between InterfacesThe problem to be solved in any case is the detection and bridging of inconsistencies between individual interfaces of
different software. Further complications often arise only in their interaction. In order to prevent conflicts and bridge inconsistencies, a uniform interface is created without having to modify the software or components themselves
The term wrapper and its possible interpretations.
In order to illustrate the diverse uses of the term wrapper, a few examples are brought together below.
Inthe simplest case, a wrapper
is more or lessan adapter
thatconnects incompatible systems. The wrapper first accesses the data
from the interface offered to it, transforms it into the desired form and then passes this data on to the target system. This path works analogously in reversedata sources - i.e. relational as well as non-relational - database and application systems or also file servers can be connected to an SQL
server via wrappers. The wrapper provides a standardized interface for this purpose, so that all data sources can be addressed uniformly from the point of view of the SQL server. Java Database Connectivity
(JDBC), which describes a set of interfaces for using Java relational database systems, is also to be classified in this context.
The Wrapper Framework for Building Wrappers Forexample, a wrapper framework is a framework for building wrappers that are used in connection with the realization of uniform function interfaces for existing client applications - which are then encapsulated both technically and functionally.
Another example is a so-called security
wrapper for runtime monitoring of application systems.
This wrapper has the task of observing the behavior at the interface of a component and then comparing it, for example, with the specified security policy of the overall system.
A final example is the wrapper class known in Java
Wrapper classes allow the conversion of a primitive data type into a string and vice versa from a string back into a primitive data type. In addition, so-called wrapper objects are responsible for encapsulating a simple primitive data type in an object
. The basic idea of the wrapper design pattern (or adapter pattern) is to realize the adaptation of the interface to another interface, which can then be used by a client. The wrapper pattern allows classes that could otherwise not work together because of incompatible interfaces.