rest - REST暗号トランザクションを開く

Question

Groovy でトランザクションを開くスクリプトを作成しようとしています。現在持っている:

def static transaction(statement, params,success, error)
{
    def http = new HTTPBuilder( 'http://localhost:7474' )
    http.request( POST, JSON ) {
        uri.path = '/db/data/transaction'
        headers.'X-Stream' = 'true'
        requestContentType = JSON
        body =  [ statements : statement , params : params ?: [:] ]

        // uri.query = [ param : 'value' ]

        response.success = { resp, json ->
            if (success) success(json)
            else {
                println "Status ${resp.statusLine} Columns ${json.columns}\nData: ${json.data}"
            }
        }

        response.failure = { resp, message ->
            def result=[status:resp.statusLine.statusCode,statusText:resp.statusLine.reasonPhrase]
            result.headers = resp.headers.collect { h -> [ (h.name) : h.value ] }
            result.message = message
            if (error) {
                error(result)
            } else {
                println "Status: ${result.status} : ${result.statusText} "
                println 'Headers: ${result.headers}'
                println 'Message: ${result.message}'
            }
        }
    }
}
transaction("start n=node(*) return n",[id:56981],{ println "Success: ${it}" },{ println "Error: ${it}" })

ただし、応答で次のエラーが発生します。

Success: [commit:http://localhost:7474/db/data/transaction/4/commit, results:[], errors:[[code:40001, status:INVALID_REQUEST_FORMAT, message:Unable to deserialize request. Expected [START_OBJECT, FIELD_NAME, START_ARRAY], found [START_OBJECT, FIELD_NAME, VALUE_STRING].]]]

考え？ありがとう！