ConfigResolveOptions

Returns options where the given resolver used as a fallback if a reference cannot be otherwise resolved. This resolver will only be called after resolution has failed to substitute with a value from within the config itself and with any other resolvers that have been appended before this one. Multiple resolvers can be added using,

   ConfigResolveOptions options = ConfigResolveOptions.defaults()
       .appendResolver(primary)
       .appendResolver(secondary)
       .appendResolver(tertiary);

With this config unresolved references will first be resolved with the primary resolver, if that fails then the secondary, and finally if that also fails the tertiary.

If all fallbacks fail to return a substitution "allow unresolved" determines whether resolution fails or continues. `

Returns whether the options allow unresolved substitutions. This method is mostly used by the config lib internally, not by applications.

Returns the resolver to use as a fallback if a substitution cannot be otherwise resolved. Never returns null. This method is mostly used by the config lib internally, not by applications.

Returns whether the options enable use of system environment variables. This method is mostly used by the config lib internally, not by applications.

Returns options with "allow unresolved" set to the given value. By default, unresolved substitutions are an error. If unresolved substitutions are allowed, then a future attempt to use the unresolved value may fail, but Config.resolve(ConfigResolveOptions) itself will not throw.

Returns options with use of environment variables set to the given value.