Access all Environment properties as a Map or Properties object

Question

I am using annotations to configure my spring environment like this    Configuration      PropertySource  classpath  config default properties       public class GeneralApplicationConfiguration implements WebApplicationInitializer         Autowired     Environment env      This leads to my properties from default properties being part of the Environment  I want to use the  PropertySource mechanism here  because it already provides the possibility to overload properties through several fallback layers and different dynamic locations  based on the environment settings  e g  config dir location   I just stripped the fallback to make the example easier   However  my problem now is that I want to configure for example my datasource properties in default properties  You can pass the settings to the datasource without knowing in detail what settings the datasource expects using   Properties p       datasource setProperties p     However  the problem is  the Environment object is neither a Properties object nor a Map nor anything comparable  From my point of view it is simply not possible to access all values of the environment  because there is no keySet or iterator method or anything comparable    Properties p  lt     Environment env    Am I missing something  Is it possible to access all entries of the Environment object somehow  If yes  I could map the entries to a Map or Properties object  I could even filter or map them by prefix - create subsets as a standard java Map     This is what I would like to do  Any suggestions

User · Accepted Answer

You need something like this  maybe it can be improved  This is a first attempt       import org springframework core env PropertySource  import org springframework core env AbstractEnvironment  import org springframework core env Environment  import org springframework core env MapPropertySource        Configuration      org springframework context annotation PropertySource  classpath  config default properties       public class GeneralApplicationConfiguration implements WebApplicationInitializer         Autowired     Environment env       public void someMethod                         Map lt String  Object gt  map   new HashMap            for Iterator it     AbstractEnvironment  env  getPropertySources   iterator    it hasNext                    PropertySource propertySource    PropertySource  it next                if  propertySource instanceof MapPropertySource                    map putAll   MapPropertySource  propertySource  getSource                                                     Basically  everything from the Environment that s a MapPropertySource  and there are quite a lot of implementations  can be accessed as a Map of properties

User · Answer

The original question hinted that it would be nice to be able to filter all the properties based on a prefix  I have just confirmed that this works as of Spring Boot 2 1 1 RELEASE  for Properties or Map lt String String gt   I m sure it s worked for while now  Interestingly  it does not work without the prefix   qualification  i e  I do not know how to get the entire environment loaded into a map  As I said  this might actually be what OP wanted to begin with  The prefix and the following     will be stripped off  which might or might not be what one wants    ConfigurationProperties prefix    abc    Bean public Properties getAsProperties         return new Properties        Bean public MyService createService         Properties properties   getAsProperties        return new MyService properties       Postscript  It is indeed possible  and shamefully easy  to get the entire environment  I don t know how this escaped me    ConfigurationProperties  Bean public Properties getProperties         return new Properties

User · Answer

Working with Spring Boot 2  I needed to do something similar  Most of the answers above work fine  just beware that at various phases in the app lifecycles the results will be different   For example  after a ApplicationEnvironmentPreparedEvent any properties inside application properties are not present  However  after a ApplicationPreparedEvent event they are

User · Answer

As this Spring s Jira ticket  it is an intentional design  But the following code works for me    public static Map lt String  Object gt  getAllKnownProperties Environment env        Map lt String  Object gt  rtn   new HashMap lt  gt         if  env instanceof ConfigurableEnvironment            for  PropertySource lt   gt  propertySource     ConfigurableEnvironment  env  getPropertySources                  if  propertySource instanceof EnumerablePropertySource                    for  String key     EnumerablePropertySource  propertySource  getPropertyNames                          rtn put key  propertySource getProperty key                                                        return rtn

User · Answer

Spring won t allow to decouple via java util Properties from Spring Environment   But Properties load   still works in a Spring boot application   Properties p   new Properties    try  InputStream is   getClass   getResourceAsStream   my properties          p load is

User · Answer

I had the requirement to retrieve all properties whose key starts with a distinct prefix  e g  all properties starting with  log4j appender    and wrote following Code  using streams and lamdas of Java 8     public static Map lt String Object gt  getPropertiesStartingWith  ConfigurableEnvironment aEnv                                                              String aKeyPrefix         Map lt String Object gt  result   new HashMap lt  gt          Map lt String Object gt  map   getAllProperties  aEnv         for  Entry lt String  Object gt  entry   map entrySet                  String key   entry getKey             if   key startsWith  aKeyPrefix                           result put  key  entry getValue                           return result     public static Map lt String Object gt  getAllProperties  ConfigurableEnvironment aEnv         Map lt String Object gt  result   new HashMap lt  gt         aEnv getPropertySources   forEach  ps - gt  addAll  result  getAllProperties  ps            return result     public static Map lt String Object gt  getAllProperties  PropertySource lt   gt  aPropSource         Map lt String Object gt  result   new HashMap lt  gt          if   aPropSource instanceof CompositePropertySource                CompositePropertySource cps    CompositePropertySource  aPropSource          cps getPropertySources   forEach  ps - gt  addAll  result  getAllProperties  ps                return result             if   aPropSource instanceof EnumerablePropertySource lt   gt                  EnumerablePropertySource lt   gt  ps    EnumerablePropertySource lt   gt   aPropSource          Arrays asList  ps getPropertyNames     forEach  key - gt  result put  key  ps getProperty  key                return result                note  Most descendants of PropertySource are EnumerablePropertySource  There are some        few others like JndiPropertySource or StubPropertySource     myLog debug   Given PropertySource is instanceof     aPropSource getClass   getName                        and cannot be iterated          return result      private static void addAll  Map lt String  Object gt  aBase  Map lt String  Object gt  aToBeAdded         for  Entry lt String  Object gt  entry   aToBeAdded entrySet                  if   aBase containsKey  entry getKey                             continue                     aBase put  entry getKey    entry getValue                Note that the starting point is the ConfigurableEnvironment which is able to return the embedded PropertySources  the ConfigurableEnvironment is a direct descendant of Environment   You can autowire it by    Autowired private ConfigurableEnvironment  myEnv    If you not using very special kinds of property sources  like JndiPropertySource  which is usually not used in spring autoconfiguration  you can retrieve all properties held in the environment    The implementation relies on the iteration order which spring itself provides and takes the first found property  all later found properties with the same name are discarded  This should ensure the same behaviour as if the environment were asked directly for a property  returning the first found one    Note also that the returned properties are not yet resolved if they contain aliases with the        operator  If you want to have a particular key resolved you have to ask the Environment directly again   myEnv getProperty  key

User · Answer

This is an old question  but the accepted answer has a serious flaw  If the Spring Environment object contains any overriding values  as described in Externalized Configuration   there is no guarantee that the map of property values it produces will match those returned from the Environment object   I found that simply iterating through the PropertySources of the Environment did not  in fact  give any overriding values  Instead it produced the original value  the one that should have been overridden  Here is a better solution   This uses the EnumerablePropertySources of the Environment to iterate through the known property names  but then reads the actual value out of the real Spring environment   This guarantees that the value is the one actually resolved by Spring  including any overriding values  Properties props   new Properties    MutablePropertySources propSrcs     AbstractEnvironment  springEnv  getPropertySources    StreamSupport stream propSrcs spliterator    false           filter ps - gt  ps instanceof EnumerablePropertySource           map ps - gt    EnumerablePropertySource  ps  getPropertyNames             flatMap Arrays   lt String gt stream           forEach propName - gt  props setProperty propName  springEnv getProperty propName

User · Answer

I though I d add one more way  In my case I supply this to com hazelcast config XmlConfigBuilder which only needs java util Properties to resolve some properties inside the Hazelcast XML configuration file  i e  it only calls getProperty String  method  So  this allowed me to do what I needed   RequiredArgsConstructor public class SpringReadOnlyProperties extends Properties      private final org springframework core env Environment delegate      Override   public String getProperty String key        return delegate getProperty key           Override   public String getProperty String key  String defaultValue        return delegate getProperty key  defaultValue           Override   public synchronized String toString         return getClass   getName      quot   quot    delegate    quot   quot           Override   public boolean equals Object o        if  this    o  return true      if  o    null    getClass      o getClass    return false      if   super equals o   return false      SpringReadOnlyProperties that    SpringReadOnlyProperties  o      return delegate equals that delegate           Override   public int hashCode         return Objects hash super hashCode    delegate          private void throwException         throw new RuntimeException  quot This method is not supported quot             all methods below throw the exception      override all methods      P S  I ended up not using this specifically for Hazelcast because it only resolves properties for XML file but not at runtime  Since I also use Spring  I decided to go with a custom org springframework cache interceptor AbstractCacheResolver getCacheNames  This resolves properties for both situations  at least if you use properties in cache names

User · Answer

For Spring Boot  the accepted answer will overwrite duplicate properties with lower priority ones  This solution will collect the properties into a SortedMap and take only the highest priority duplicate properties   final SortedMap lt String  String gt  sortedMap   new TreeMap lt  gt     for  final PropertySource lt   gt  propertySource   env getPropertySources          if    propertySource instanceof EnumerablePropertySource           continue      for  final String name     EnumerablePropertySource lt   gt   propertySource  getPropertyNames            sortedMap computeIfAbsent name  propertySource  getProperty

User · Answer

The other answers have pointed out the solution for the majority of cases involving PropertySources  but none have mentioned that certain property sources are unable to be casted into useful types   One such example is the property source for command line arguments  The class that is used is SimpleCommandLinePropertySource  This private class is returned by a public method  thus making it extremely tricky to access the data inside the object  I had to use reflection in order to read the data and eventually replace the property source   If anyone out there has a better solution  I would really like to see it  however  this is the only hack I have gotten to work

[spring] Access all Environment properties as a Map or Properties object

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