How to inject a Map in java springs?

Question

How to inject a Map in java spring framework? If possible please provide some sample code.

Is the following legal?

<property name="testMap">
    <map>
        <entry>
            <key>
                <value>test</value>
            </key>
            <value>
                <list>
                    <value>String</value>
                    <value>String</value>
                </list>
            </value>
        </entry>
    </map> 
</property>

score 35 · Accepted Answer · edited May 28 '18 at 07:23

35

Define a Map like this first inside your applicationContext.xml:

<util:list id="list1">
    <value>foo@bar.com</value>
    <value>foo1@bar.com</value>
</util:list>

<util:list id="list2">
    <value>foo2@bar.com</value>
    <value>foo3@bar.com</value>
</util:list>

<util:map id="emailMap" value-type="java.util.List">
    <!-- Map between String key and List -->
    <entry key="entry1" value-ref="list1" />
    <entry key="entry2" value-ref="list2" />
    ...
</util:map>

Then use this Map in any bean of yours like this:

<bean id="myBean" class="com.sample.beans">
    <property name="emailMap" ref="emailMap" />
</bean>

edited May 28 '18 at 07:23

Ahmed Ashour

5,179
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answered Mar 18 '11 at 05:14

anubhava

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how to do this in .properties file? – Artanis Zeratul Mar 21 '21 at 06:52
Please check: https://stackoverflow.com/a/50979119/548225 – anubhava Mar 21 '21 at 14:44

score 26 · Answer 2 · edited Jan 27 '17 at 08:09

I think your syntax is not legal as spring throws org.xml.sax.SAXParseException when processing the bean configuration xml .

It should work after removing the <value> tag around the <list>.

<property name="testMap">
    <map>
        <entry>
            <key>
                <value>test</value>
            </key>

             <list>
                    <value>String</value>
                    <value>String</value>
             </list>
        </entry>
    </map> 
</property>

score 7 · Answer 3 · edited May 28 '18 at 07:24

This is my example:

<bean class="com.common.handlermgmnt.HandlerMapAdder">
    <constructor-arg index="0" type="java.util.Map">
        <map key-type="java.lang.String" value-type="com.common.ViewWidget">
            <entry key="DefaultView">
                <bean class="com.common.DefaultViewWidget"/>
            </entry>
            <entry key="AnotherView">
                <bean class="com.common.AnotherViewWidget"/>
            </entry>
        </map>
    </constructor-arg>
    <constructor-arg index="1" type="com.common.handlermgmnt.HandlerManager" ref="widget_handlerManager"/>
</bean>

score 2 · Answer 4 · edited Jan 27 '17 at 08:10

2

Inject it using SpEL. #{id}. this works for me.

in the .xml:

<util:map id="roleLocationMap">
    <entry key="ROLE_ADMIN" value-ref="listA" />
    <entry key="ROLE_USER" value-ref="listB" />
</util:map>

in the .java

@Autowired
public MainController(
        @Value("#{roleLocationMap}") final Map<String, List<String>> roleLocationMap) {
    this.roleLocationMap = roleLocationMap;
}

edited Jan 27 '17 at 08:10

Ahmed Ashour

5,179
10
35
56

answered Jun 17 '14 at 03:14

Titi Wangsa bin Damhore

7,101
4
31
36

how to do this in .properties file? – Artanis Zeratul Mar 21 '21 at 06:53

score 1 · Answer 5 · edited Jan 27 '17 at 08:09

Just ran into this case myself. If no need to reuse the list values as independent beans elsewhere, you could use this shorter version, without using 'value-ref':

<util:map id="mymap">
    <entry key="key1">
        <util:list>
            <value>val1</value>
            <value>val2</value>
        </util:list>
    </entry>
    <entry key="key2">
        <util:list>
            <value>val2</value>
            <value>val3</value>
            <value>val4</value>
        </util:list>
    </entry>
</util:map>

And, wire it up in your Java code like this:

@Resource(name="mymap")
Map<String, List<String>> mapKey_List;

How to inject a Map in java springs?

5 Answers5

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