Improve performance of MapPropertySource.containsProperty [SPR-12224]

[spring-projects-issues]

Phil Webb opened SPR-12224 and commented

The MapPropertySource.containsProperty() method is not currently implemented directly, instead the EnumerablePropertySource implementation is used. This means for each containsProperty() call map keys are converted to an array then iterated.

We can improve performance by looking in the map directly.

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Affects: 4.1 GA

Referenced from: commits 587a816, e71fbb9, 752574d, 65cc57d

[spring-projects-issues]

Juergen Hoeller commented

This change unfortunately has a side effect for SystemEnvironmentPropertySource (which extends MapPropertySource): When used with an active JVM SecurityManager, it may fail when checking the availability of property naming variants. Our EnvironmentSecurityManagerIntegrationTests does fail on Windows for that reason.

Modifying SystemEnvironmentPropertySource to not call super.containsProperty anymore but rather to perform the default check against getPropertyNames() as we used to do before makes the problem go away. This should be a fine compromise, with the regular MapPropertySource still being able to perform an optimized containsProperty lookup.

Juergen