Spring Java config wraps injected map

Question

I recently switched from using Spring's XML configuration to its Java configuration and am encountering a strange issue.

The XML configuration was:

<util:map id="myMap">
    <entry key="a" value="aValue"/>
    <entry key="b" value="bValue"/>
    <entry key="c" value="cValue"/>
</util:map>

<bean id="myBean" class="my.MyClass">
    <property name="myMap" ref="myMap"/>
</bean>

The Java configuration is:

@Bean
public Map<String, Object> myMap() {

    Map<String, Object> myMap = new HashMap<>();
    myMap.put("a", "aValue");
    myMap.put("b", "bValue");
    myMap.put("c", "cValue");

    return myMap;
}

@Bean
public MyClass myBean(@Qualifier("myMap") final Map<String, Object> myMap) {

    MyClass myBean = new MyClass();
    myBean.setMyMap(myMap);

    return myBean;
}

Both beans are declared in different files, I grouped them here to make it easier to read. The map contains references too, not only strings.

I would expect to be able to use myMap in the second bean but instead Spring injects the following map:

{ myMap = { a=aValue, b=bValue, c=cValue } }

I don't understand why Spring wraps the map into another map, and why it doesn't behave the same way with the XML configuration.

Any ideas?

Answer 1

There is an issue @Autowired-ing a Map even defining the bean name and since as-per the comments you can't use the suggested @Resource annotation there is an alternative by using the @Value annotation defining the bean name:

@Bean
public MyClass myBean(@Value("#{myMap}") final Map<String, Object> myMap) {
//..
}