Discussion :

[V4Vendetta]

Bonsoir,

J'aimerais savoir qu'elle est l'utilité d'utiliser un alias dans nos déclarations des beans dans la configurations xml ?

Merci d'avace

[Khaled.Noordin]

Salut
Qu'est ce qu'un alias?

[JeitEmgie]

J'aimerais savoir qu'elle est l'utilité d'utiliser un alias dans nos déclarations des beans dans la configurations xml ?

In a bean definition itself, you can supply more than one name for the bean, by using a combination of up to one name specified by the id attribute, and any number of other names in the name attribute. These names can be equivalent aliases to the same bean, and are useful for some situations, such as allowing each component in an application to refer to a common dependency by using a bean name that is specific to that component itself.

Specifying all aliases where the bean is actually defined is not always adequate, however. It is sometimes desirable to introduce an alias for a bean that is defined elsewhere. This is commonly the case in large systems where configuration is split amongst each subsystem, each subsystem having its own set of object definitions. In XML-based configuration metadata, you can use the element to accomplish this.
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As a concrete example, consider the case where component A defines a DataSource bean called componentA-dataSource, in its XML fragment. Component B would however like to refer to the DataSource as componentB-dataSource in its XML fragment. And the main application, MyApp, defines its own XML fragment and assembles the final application context from all three fragments, and would like to refer to the DataSource as myApp-dataSource.

le "commonly the case in large systems" signifie simplement que si vous vous posez la question de l'usage des alias, c'est que vous n'en avez pas besoin : vous ne travaillez pas sur des projets suffisamment complexes pour que le cas se présente.


http://www.springframework.org/schem...ring-beans.xsd :

Code :

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<xsd:element name="alias">
<xsd:annotation>
<xsd:documentation>
<![CDATA[
Defines an alias for a bean (which can reside in a different definition resource).
]]>
</xsd:documentation>
</xsd:annotation>
<xsd:complexType>
<xsd:complexContent>
<xsd:restriction base="xsd:anyType">
<xsd:attribute name="name" type="xsd:string" use="required">
<xsd:annotation>
<xsd:documentation>
<![CDATA[ The name of the bean to define an alias for. ]]>
</xsd:documentation>
</xsd:annotation>
</xsd:attribute>
<xsd:attribute name="alias" type="xsd:string" use="required">
<xsd:annotation>
<xsd:documentation>
<![CDATA[ The alias name to define for the bean. ]]>
</xsd:documentation>
</xsd:annotation>
</xsd:attribute>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
…