如何在Spring XML配置文件类中指定Map属性？

Question

Here is what I mean, see following spring XML file:

<bean id = 'a' class="A">
   <property name="mapProperty">
       <map>
          <entry key="key1"><value>value1</value></entry>
       </map>
   </property>
</bean>

And my class looks like following:

class A {
   HashMap mapProperty

}

How can I tell in spring XML file that Map to be injected is of type java.util.HashMap ? Or in general can I provide class name for the Map ?

Please note, I cannot change the class A to use Map instead of HashMap

Thanks in advance !!

Answer 1

You can use util:map

<util:map id="someId" map-class="java.util.HashMap">
    <entry key="key1">
        <value>value1</value>
    </entry>
</util:map>

<bean id="a" class="A">
    <property name="mapProperty" ref="someId">
    </property>
</bean>

Don't forget to add the util namespace.

Answer 2

You can use util:map tag from the util schema. Here's an example:

<util:map id="utilmap" map-class="java.util.HashMap">
    <entry key="key1" value="value1"/>
    <entry key="key2" value="value2"/>
</util:map>

<bean id = 'a' class="A">
   <property name="mapProperty" ref="utilmap" />
</bean>

BTW, you should not use raw type HashMap . Use a parameterized type instead - HashMap<String, String> .

Answer 3

To extend Sotirios Delimanolis' answer : See this example on how to include the util namespace:

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/util 
           http://www.springframework.org/schema/util/spring-util.xsd">
</beans>

Note that you will need to amend the schemaLocation as well ;)