[CAMEL-18612] Inconsistency in JsonPath component causes problems with databinding - ASF JIRA

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Details

Type: Bug
Status: Resolved
Priority: Major
Resolution: Fixed
Affects Version/s: None
Fix Version/s: 3.18.3, 3.20.0
Component/s: camel-jsonpath
Labels:
None

Estimated Complexity:
Unknown

Description

Inconsistent treatment of jsonpath expression result causes problems with data binding. When jsonpath evaluates to an array element, this piece of code threats it as a single object, making it impossible to bind to an array of objects.

(singleElement && !resultIsCollection) {
    result = ((List) result).get(0);
    ...
}

Steps to reproduce:

Create this Camel route

from("file:work/")
        .routeId("file-route")
        .to("direct:transform");

from("direct:transform")
        .routeId("direct-transform")
        .streamCaching()
        .log("Before jsonpath transformation >>> ${body}")
        .setBody().jsonpath("$.d.results", String.class)
        .log("After jsonpath transformation >>> ${body}")
        .process(exchange -> {
            log.info("Before Jackson deserialization");

            String testResponse = exchange.getMessage().getBody(String.class);
            objectMapper.readValue(testResponse, TestResultsInfo[].class);

            log.info("After Jackson deserialization");
        })
        .to("mock:test");

Use the single-item-array.json file from the attachment

Try to bind the message body to these classes

@Data
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true)
public static class TestResultsInfo {

    String resultText;
    @JsonProperty(value = "AddressInfo")
    TestAddressInfo addressInfo;

}

@Data
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true)
public static class TestAddressInfo {

    @JsonProperty(value = "City")
    String city;
    @JsonProperty(value = "State")
    String street;

}

It will fail because it's not possible to bind it to TestResultsInfo[]. If you add a second element to the array (or use multiple-item-array.json file instead), it will work fine.