SpringBoot Inconsistent binding from environment varaibles to maps

I've noticed an inconsistency in properties binding from an ENV variable and property defined in application.properties

Consider following example:

@ConfigurationProperties("com.test")
public class Props {
    private Map<String, Map<String, String>> property;
}

application.properties <- binding works correctly

com.test.property.foo.bar=value

Environment variable <- binding fails

export COM_TEST_PROPERTY_CCC_DDD=VALUE

I would expect that the same binding behavior for an externalized configuration. Any idea how to resolve this issue using Spring Boot 1.5.2?

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I am using Spring Boot 1.5.2, Linux Mint 18.1, Java 8 ("1.8.0_121") Demo application available: https://github.com/peterjurkovic/spring-boot-binding-demo

Comment From: dturanski

Looks like the same issue I reported as https://jira.spring.io/browse/SPR-15451

does this work? export SPRING_APPLICATION_JSON='{"com.test": {"property":{"foo": {"bar" : "value"} } } }'

Comment From: philwebb

The JSON is probably your only option with 1.5.x. We're reworking binding in Boot 2.0 to make things more consistent but unfortunately fixing inconsistencies like this in 1.5.x is very difficult.

Comment From: dturanski

@philwebb This is a great test case: compound prefix with nested maps. If 2.0 can bind this correctly it can likely handle anything.

Comment From: philwebb

@dturanski I'll make sure we add a unit test in the new code.

Comment From: mkucharek

I've just hit a similar issue with Eureka default zone with Spring Boot 2.0.0.M7 - it doesn't seem to correctly handle camel cases when binding map elements..

Comment From: snicoll

@mkucharek this issue is closed. If you believe you have found an issue, please create a minimal sample (without Spring Cloud) that we can run ourselves and create a separate issue.

Comment From: rujche

Sharing my knowledge here:

Problem same with this issue: https://github.com/spring-cloud/spring-cloud-netflix/issues/2541 I can't left comment in https://github.com/spring-cloud/spring-cloud-netflix/issues/2541, so I add comment here.

1. EUREKA_CLIENT_SERVICEURL can bind to serviceUrl which type is Map<String, String>.
2. When DEFAULTZONE bind to Map, the key value is defaultzone, （z in lowercase）。
3. When read serviceUrl，the key is defaultZone. （Z in upper case）

It's hard to fix this issue in Spring boot side, because when DEFAULTZONE map to the key in Map<String, String>, if we want to support all case, there are too much cases. DEFAULTZONE has 11 chars, it will have 2^11 cases.

What we can do is: When binding Map, all key use lower case.