Using @Value to read multiple properties at a time into a single field with Spring 2.7.x

Question

Spring 2.7.x :-

I am trying to read the below properties from application.yml in a single map which is:

my:
  map:
    propertyA1:
      firstProp: some1
      secondProp: some2
    propertyA2:
      firstProp: some1
      secondProp: some2

In my controller i have :

@Value("${my.map}")
    private Map<String, Object> myMap;

I also tried the below restructured formats for properties:

my:
  map:
    propertyA1: '{firstProp: some1, secondProp: some2}'
    propertyA2: '{firstProp: some1, secondProp: some2}'

And

my:
  map:
    propertyA1: {firstProp: some1, secondProp: some2}
    propertyA2: {firstProp: some1, secondProp: some2}

Also,

With @Value I have tried all the below combinations:

@Value("#{${my.map}}")
    private Map<String, Object> myMap;

@Value("#{${my.map}}")
    private Map<String, String> myMap;

AND

@Value("#{${my.map}}")
    private Map<String, Map<String , String>> myMap;

But every single time i get a BeanInstantianException on startup and app crashes.

This is the stacktrace with Map<String , Map<String,String>> :-


org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'changeStreamController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'my.map' in value "${my.map}"
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:955) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.23.jar:5.3.23]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.23.jar:5.3.23]
    at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66) ~[spring-boot-2.7.4.jar:2.7.4]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-2.7.4.jar:2.7.4]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.4.jar:2.7.4]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.4.jar:2.7.4]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.4.jar:2.7.4]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.4.jar:2.7.4]
    at com.example.demo.ReactiveDemoApplication.main(ReactiveDemoApplication.java:10) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.7.4.jar:2.7.4]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'my.map' in value "${my.map}"
    at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:180) ~[spring-core-5.3.23.jar:5.3.23]
    at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126) ~[spring-core-5.3.23.jar:5.3.23]
    at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.3.23.jar:5.3.23]
    at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) ~[spring-core-5.3.23.jar:5.3.23]
    at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:191) ~[spring-context-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:936) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1332) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1311) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.23.jar:5.3.23]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.23.jar:5.3.23]
    ... 22 common frames omitted

Does it have to be a Map? This is quite easy for example with a list — T A, Mar 15 '23 at 08:35
@T A it can be any collection.. I just want to fetch all the properties into a single field with only one @Value — user1354825, Mar 15 '23 at 08:47
Does this answer your question? [How to inject a Map using the @Value Spring Annotation?](https://stackoverflow.com/questions/30691949/how-to-inject-a-map-using-the-value-spring-annotation) — Abhijit Sarkar, Mar 15 '23 at 08:53

Anonymus · Answer 1 · 2023-03-15T08:31:25.937

I think you should use the @ConfigurationProperties alternative @Value

add class ConfigProperties to set value

@Configuration
@ConfigurationProperties(prefix = "my.map")
public class ConfigProperties {
private Object propertyA1;
private Object propertyA2;

// add getter setter ...
public static class Object {
    private String firstProp;
    private String secondProp;

    // add getter setter ...
}
}

After having to get value use

@Autowired
private ConfigProperties configProperties;

example UserController code:

@Autowired
private ConfigProperties configProperties;
@GetMapping(value = "/test")
public String test() {
    log.info("BaseConfigTest.test():" + configProperties.getPropertyA1().getFirstProp());
    return "hello";
}

can you provide an example ? – user1354825 Mar 15 '23 at 05:37 — user1354825, Mar 15 '23 at 05:37

Using @Value to read multiple properties at a time into a single field with Spring 2.7.x

1 Answers1