CODEWITHSUNDEEP
jsongroovyapache-nifi
amira khalifa
amira khalifa

Reputation: 117

Read FlowFile with Groovy Nifi

I try to transform an Avro file to an SQL request. My file is like this : 

{
  "type" : "record",
  "name" : "warranty",
  "doc" : "Schema generated by Kite",
  "fields" : [ {
    "name" : "id",
    "type" : "long",
    "doc" : "Type inferred from '1'"
  }, {
    "name" : "train_id",
    "type" : "long",
    "doc" : "Type inferred from '21691'"
  }, {
    "name" : "siemens_nr",
    "type" : "string",
    "doc" : "Type inferred from 'Loco-001'"
  }, {
    "name" : "uic_nr",
    "type" : "long",
    "doc" : "Type inferred from '193901'"
  }, {
    "name" : "Configuration",
    "type" : "string",
    "doc" : "Type inferred from 'ZP28'"
  }, {
    "name" : "Warranty_Status",
    "type" : "string",
    "doc" : "Type inferred from 'Out_of_Warranty'"
  }, {
    "name" : "Warranty_Data_Type",
    "type" : "string",
    "doc" : "Type inferred from 'Real_based_on_preliminary_acceptance_date'"
  }

and my code is :

import groovy.json.JsonSlurper

def ff = session.get()
if(!ff)return

//parse afro schema from flow file content
def schema = ff.read().withReader("UTF-8"){ new JsonSlurper().parse(it) }

//define type mapping
def typeMap = [
    "string"            : "varchar(255)",
    "long"              : "numeric(10)",
    [ "null", "string" ]: "varchar(255)",
    [ "null", "long" ]  : "numeric(10)",
]
//build create table statement
def createTable = "create table ${schema.name} (" +
    schema.fields.collect{ "\n  ${it.name.padRight(39)} ${typeMap[it.type]}" }.join(',') +
    "\n)"

//execute statement through the custom defined property
//SQL.mydb references http://docs.groovy-lang.org/2.4.10/html/api/groovy/sql/Sql.html object
SQL.mydb.execute(createTable)

//transfer flow file to success
REL_SUCCESS << ff

And i got this error :

ERROR nifi.processors.script.ExecuteScript ExecuteScript[id=e65b733e-0161-1000-45f0-3264d6fb51dd] ExecuteSc$ Possible solutions: getId(), find(), grep(), each(groovy.lang.Closure), find(groovy.lang.Closure), grep(java.lang.Object); rolling back session: {} org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: javax.script.ScriptException: groovy.lang.MissingMethodException: No signature of m$ Possible solutions: getId(), find(), grep(), each(groovy.lang.Closure), find(groovy.lang.Closure), grep(java.lang.Object)

Can someone help me plz

Upvotes: 0

Views: 4153

Answers (1)

mattyb
mattyb

Reputation: 12083

This references a script from another SO post, I commented there and I provided an answer on a different forum, which I will copy here for completeness:

The variable createTable is a GString, not a Java String. This causes invocation of Sql.execute(GString), which converts the embedded expressions into parameters, and you can't use a parameter for a table name. Use the following instead:

SQL.mydb.execute(createTable.toString())

This will cause the invocation of Sql.execute(String), which does not try to parameterize the statement.

Upvotes: 1

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