Package ca.marcusdunn.jsonlens.jackson

@NullMarked package ca.marcusdunn.jsonlens.jackson

A JsonModel for Jackson 3 JsonNode values: JacksonJsonModel.

// 1. Read the JSON value with your own JSON library. Keep numbers exact.
JsonMapper mapper = JsonMapper.builder()
        .enable(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS)
        .build();
JsonNode root = mapper.readTree(BOOKSTORE);

// 2. Parse the query. A query that is not valid gives an error value.
Result<JsonPathQuery, ParseError> parsed =
        JsonPathParser.standard().parse("$.store.book[?@.price < 10].title");

// 3. Apply the query to the value through a JsonModel.
switch (parsed) {
    case Result.Ok(JsonPathQuery query) -> {
        Result<List<Node<JsonNode>>, EvaluationError> result =
                JsonPathEvaluator.standard().evaluate(query, root, JacksonJsonModel.INSTANCE);
        switch (result) {
            case Result.Ok(List<Node<JsonNode>> nodes) -> {
                for (Node<JsonNode> node : nodes) {
                    lines.add(node.path() + " = " + node.value());
                }
            }
            case Result.Err(EvaluationError error) -> lines.add("Overflow: " + error.message());
        }
    }
    case Result.Err(ParseError error) -> lines.add("Bad query: " + error.message());
}
// lines:
//   $['store']['book'][0]['title'] = "Sayings of the Century"
//   $['store']['book'][2]['title'] = "Moby Dick"