flowable/flowable-engine · error · FlowableIllegalArgumentException

The key cannot be null.

Error message

The key cannot be null.

What it means

REST request validation in UserInfoCollectionResource.setUserInfo: a user-info entry was submitted without a key. Info entries are key/value pairs addressed by key, so a missing key makes the request unprocessible.

Solutions

1. Include a non-null 'key' field in the request JSON
2. Validate the payload client-side before the call

When it happens

Trigger: Thrown at modules/flowable-rest/src/main/java/org/flowable/rest/service/api/identity/UserInfoCollectionResource.java:78 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/e04fad4f56c0fbaf. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-rest/src/main/java/org/flowable/rest/service/api/identity/UserInfoCollectionResource.java:78

        return restResponseFactory.createUserInfoKeysResponse(identityService.getUserInfoKeys(user.getId()), user.getId());
    }

    @ApiOperation(value = "Create a new user’s info entry", tags = { "Users" }, nickname = "createUserInfo", code = 201)
    @ApiResponses(value = {
            @ApiResponse(code = 201, message = "Indicates the user was found and the info has been created."),
            @ApiResponse(code = 400, message = "Indicates the key or value was missing from the request body. Status description contains additional information about the error."),
            @ApiResponse(code = 404, message = "Indicates the requested user was not found."),
            @ApiResponse(code = 409, message = "Indicates there is already an info-entry with the given key for the user, update the resource instance (PUT).")
    })
    @PostMapping(value = "/identity/users/{userId}/info", produces = "application/json")
    @ResponseStatus(HttpStatus.CREATED)
    public UserInfoResponse setUserInfo(@ApiParam(name = "userId") @PathVariable String userId, @RequestBody UserInfoRequest userRequest) {

        User user = getUserFromRequest(userId);

        if (userRequest.getKey() == null) {
            throw new FlowableIllegalArgumentException("The key cannot be null.");
        }
        if (userRequest.getValue() == null) {
            throw new FlowableIllegalArgumentException("The value cannot be null.");
        }

        String existingValue = identityService.getUserInfo(user.getId(), userRequest.getKey());
        if (existingValue != null) {
            throw new FlowableConflictException("User info with key '" + userRequest.getKey() + "' already exists for this user.");
        }

        identityService.setUserInfo(user.getId(), userRequest.getKey(), userRequest.getValue());

        return restResponseFactory.createUserInfoResponse(userRequest.getKey(), userRequest.getValue(), user.getId());
    }
}

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