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If this sounds vague, its because there is not just one ObjectProvider; there's a whole set of them, forming a chain of command. The commands in the chain may provide an object based on the parameter type, or based on additional annotations on the parameter.

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Usually, the symbol reference is only part of the string, i.e. @Value("${report.dir}/${report.name}.txt")

@Symbol Annotation Provider

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The tapestry-core module defines the Alias object provider, which is used as a way to override services or disambiguate services (when multiple services implement the same interface).

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