org.springframework.core.env

Class SystemEnvironmentPropertySource


  • public class SystemEnvironmentPropertySource
    extends MapPropertySource
    Specialization of MapPropertySource designed for use with system environment variables. Compensates for constraints in Bash and other shells that do not allow for variables containing the period character; also allows for uppercase variations on property names for more idiomatic shell use.

    For example, a call to getProperty("foo.bar") will attempt to find a value for the original property or any 'equivalent' property, returning the first found:

    • foo.bar - the original name
    • foo_bar - with underscores for periods (if any)
    • FOO.BAR - original, with upper case
    • FOO_BAR - with underscores and upper case
    The same applies for calls to containsProperty(String), which returns true if any of the above properties are present, otherwise false.

    This feature is particularly useful when specifying active or default profiles as environment variables. The following is not allowable under Bash

    spring.profiles.active=p1 java -classpath ... MyApp
    However, the following syntax is permitted and is also more conventional.
    SPRING_PROFILES_ACTIVE=p1 java -classpath ... MyApp

    Enable debug- or trace-level logging for this class (or package) for messages explaining when these 'property name resolutions' occur.

    This property source is included by default in StandardEnvironment and all its subclasses.

    Since:
    3.1
    Author:
    Chris Beams
    See Also:
    StandardEnvironment, AbstractEnvironment.getSystemEnvironment(), AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME
    • Constructor Detail

      • SystemEnvironmentPropertySource

        public SystemEnvironmentPropertySource(String name,
                                       Map<String,Object> source)
        Create a new SystemEnvironmentPropertySource with the given name and delegating to the given MapPropertySource.
    • Method Detail

      • containsProperty

        public boolean containsProperty(String name)
        Return true if a property with the given name or any underscore/uppercase variant thereof exists in this property source.
        Overrides:
        containsProperty in class  EnumerablePropertySource<Map<String,Object>>
        Parameters:
        name - the name of the property to find