Spring Boot - inject static map from application.yml

Question

I refered Spring Boot - inject map from application.yml for injecting map from application.yml file

My application.yml snippet is below

easy.app.pairMap:
    test1: 'value1' 
    test2: 'value2'

Properties file is like below

@Component
@Configuration
@ConfigurationProperties("easy.app")
@EnableConfigurationProperties
public class TestProperties {



private Map<String, String> pairMap= new HashMap<String, String>();

public void setPairMap(Map<String, String> pairMap) {
    this.pairMap= pairMap;
}

}

The above given code works .Map is not read from application.yml file when the 'pairMap' is set as static as below.

@Component
@Configuration
@ConfigurationProperties("easy.app")
@EnableConfigurationProperties
public class TestProperties {



private static Map<String, String> pairMap= new HashMap<String, String>();

public static void setPairMap(Map<String, String> pairMap) {
    TestProperties .pairMap= pairMap;
}

}

PS : The issue is only when injecting map , but not on injecting string. Why is this behaviour?

ie the following injection of string in the following configuration works , but not the map injection

easy.app.key1: 'abc'

easy.app.pairMap:
     test1: 'value1' 
     test2: 'value2'

Properties file like below

@Component
@Configuration
@ConfigurationProperties("easy.app")
@EnableConfigurationProperties
public class TestProperties {



private Map<String, String> pairMap= new HashMap<String, String>();

private static String key1;

public static void setPairMap(Map<String, String> pairMap) {
    this.pairMap= pairMap;
}

public static void setKey1(String key1) {
    TestProperties.key1= key1;
}



public String getKey1(){
    return key1;
}

Possible duplicate of [@autowired in static classes](https://stackoverflow.com/questions/11392692/autowired-in-static-classes). I think that thread will show you the way. — Robert Moskal, Dec 07 '18 at 15:18
Answer is: [here](https://stackoverflow.com/a/11324464/5743040), but don't use static explains: [here](https://stackoverflow.com/a/7253751/5743040) — Andrii Vdovychenko, Dec 07 '18 at 17:07
some of the fields including map in myclass need to be static and the others need to be non static — Abhi, Dec 12 '18 at 06:27
since it is spring boot application you can inject map through `@ConfigurationProperties("easy.app")` and you can use it in whole application — Deadpool, Dec 14 '18 at 04:00

Shiva Kumar N · Answer 1 · 2018-12-07T15:40:24.923

Fix with this:

easy:
  app:
    pairMap:
      test1: value1
      test2: value2

 @CompileStatic
 @Component
 @EnableConfigurationProperties
 class ConfigHolder {

   @Value(value = '${easy.app.pairMap.test1}')
   String test1Valse;

   @Value(value = '${easy.app.pairMap.test2}')
   String test2Valse;
 }



@CompileStatic
@Configuration
@EnableConfigurationProperties
public class TestProperties {

  @Autowired
  ConfigHolder configHolder;



  private Map<String, String> pairMap= new HashMap<String, String>();


  public void setPairMap(Map<String, String> pairMap) {
     if(pairMap != null && !pairMap.isNotEmpty()) {
        this.pairMap = pairMap;
     } else {
        this.pairMap.put("test 1", ${configHolder.test1Valse});
        this.pairMap.put("test 2", ${configHolder.test2Valse});
     }
  }

}

Spring Boot - inject static map from application.yml

1 Answers1