Supply more useful variables to @Encrypted keyId SPEL expression

[hellproxy]

The keyId SPEL expression for the @Encrypted annotation is great for avoiding hard-coding of encryption key ids. See docs here. Example:

@Document
@Encrypted(keyId = "#{mongocrypt.keyId(#target)}")
static class Patient {

    @Id String id;
    String name;

    @Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Random")
    String bloodType;

    @Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic")
    Integer ssn;
}

However the value bound to #target isn't particularly useful, it's just the simple class name (minus the package!) of the annotated class. See this line:

ctx.setVariable("target", getType().getSimpleName());

This limits the usefulness of the SPEL expression, especially in scenarios where users might want to use different encryption keys for different collections.

A simple but impactful enhancement would be to bind collection as a variable:

ctx.setVariable("collection", getCollection());

Curious to hear people's thoughts on this.

[mp911de]

Thanks for looking into this. If you want, feel free to submit a pull request to add the collection to the context.