Hierarchy Lookup for Expression Resolver

[dipak-pawar]

Problem:

Currently we have StringPropertyReplacer to resolve expression ${p}.

I am running my tests with failsafe configuration like

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-failsafe-plugin</artifactId>
    <configuration>
       <systemPropertyVariables>
         <APP_NAME>${project.artifactId}</APP_NAME>
       </systemPropertyVariables>
     </configuration>
</plugin>

If I am using expression language to resolve ${APP_NAME} , I will use

 @RouteURL("${APP_NAME}")
 private URL baseURL;

It works fine from mvn build. But if I tries to run if from IDE(che), it doesn't resolve this property which is fine becuase we don't have system property or env variable set. But even if I set env variable by name APP_NAME, it won't resolve it because during test execution core will set all env vars to system properties by prefixing it with env., which mean APP_NAME env variable will be available in system properties by name env.APP_NAME.

To make it workable I have to change code to following

 @RouteURL("${env.APP_NAME}")
 private URL baseURL;

Proposed Solution:

It'll be good if we provide some hierarchy for lookup `System.getProperty(APP_NAME) - > System.getenv(APP_NAME) -> System.getProperty("env.APP_NAME"), so user can easily use same code for both the cases(through system property and env var)

 @RouteURL("${APP_NAME}")
 private URL baseURL;

[bartoszmajsak]

Just remember to keep env.APP_NAME logic for backward compatibility.