I am kinda new to Spring.

My Springframework version is 5.3.9.

What specific implementation does Spring choose to be injected?

for example I have

// bean class

private Map<String,String> myMap;

public void setMyMap(Map<String, String> myMap) {
    this.myMap = myMap;
}

<!-- bean def xml -->
<bean id="student" >
    <property name="myMap">
        <map>
            <entry key="name" value="someName"/>
            <entry key="school" value="someSchool"/>
        </map>
    </property>
</bean>

Questions:

• Does Spring choose HashMap as implementation to be injected? Or Other implementation?
• Does Spring allow choose of implementation class
• Suppose the default implementation class will change with versions where could I find docs about this.

Many Thanks

My Efforts:

• I read the spring-framewwork5.x doc and searched for collection implementation class but failed to find it.

• I also try to read the spring-framework5.x sourcecode org.springframework.beans.factory.supportDefaultListableBeanFactory#resolveMultipleBeans But still fail to find the implementation class.

• My Java is not excellent

• Googled about it but didn't find

CodePudding user response：

In this Spring 5.3.9 docs it stated that

You can also explicitly control the exact type of Map that is instantiated and populated by using the 'map-class' attribute on the <util:map/> element.

Example:

<util:map id="emails" map->
    <entry key="pechorin" value="[email protected]"/>
    <entry key="raskolnikov" value="[email protected]"/>
    <entry key="stavrogin" value="[email protected]"/>
    <entry key="porfiry" value="[email protected]"/>
</util:map>

They don't state the default implementation, it's only stated that:

If no 'map-class' attribute is supplied, the container chooses a Map implementation.

I'd suggest printing your map class name to figure out the default type.