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How to fill HashMap from java property file with Spring @Value

Is it possible to use Spring @Value, to map values from properties file to the HashMap.

Currently I have something like this, and mapping one value is not a problem. But I need to map custom values in HashMap expirations. Is something like this possible?

@Service
@PropertySource(value = "classpath:my_service.properties")
public class SomeServiceImpl implements SomeService {


    @Value("#{conf['service.cache']}")
    private final boolean useCache = false;

    @Value("#{conf['service.expiration.[<custom name>]']}")
    private final HashMap<String, String> expirations = new HashMap<String, String>();

Property file: ‘my_service.properties’

service.cache=true
service.expiration.name1=100
service.expiration.name2=20

Is it posible to map like this key:value set

  • name1 = 100

  • name2 = 20

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Answer

I make one solution inspired by the previous post.

Register property file in the Spring configuration:

<util:properties id="myProp" location="classpath:my.properties"/>

And I create component:

@Component("PropertyMapper")
public class PropertyMapper {

    @Autowired
    ApplicationContext applicationContext;

    public HashMap<String, Object> startWith(String qualifier, String startWith) {
        return startWith(qualifier, startWith, false);
    }

    public HashMap<String, Object> startWith(String qualifier, String startWith, boolean removeStartWith) {
        HashMap<String, Object> result = new HashMap<String, Object>();

        Object obj = applicationContext.getBean(qualifier);
        if (obj instanceof Properties) {
            Properties mobileProperties = (Properties)obj;

            if (mobileProperties != null) {
                for (Entry<Object, Object> e : mobileProperties.entrySet()) {
                    Object oKey = e.getKey();
                    if (oKey instanceof String) {
                        String key = (String)oKey;
                        if (((String) oKey).startsWith(startWith)) {
                            if (removeStartWith) 
                                key = key.substring(startWith.length());
                            result.put(key, e.getValue());
                        }
                    }
                }
            }
        }

        return result;
    }
}

And when I want to map all properties that begin with specifix value to HashMap, with @Value annotation:

@Service
public class MyServiceImpl implements MyService {

    @Value("#{PropertyMapper.startWith('myProp', 'service.expiration.', true)}")
    private HashMap<String, Object> portalExpirations;
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