hadoop - How to pass Hive conf variable in hive udf?

Question

I want to pass hive conf variable to hive UDF.

below is a code snippet.

hive -f ../hive/testHive.sql -hivevar testArg=${testArg}

Below is hive UDF call.

select setUserDefinedValueForColumn(columnName,'${testArg}') from testTable;

In udf I am getting value of testArg as null.

Please advice me how to use hive conf variable in udf and how to access Hive configuration in hive UDF?

Answer 1

I think that you should pass hive variable as 'hiveconf' using below command:

hive --hiveconf testArg="my test args" -f ../hive/testHive.sql

Then you may have below code inside a GenericUDF evaluate() method:

@Override
 public Object evaluate(DeferredObject[] args) throws HiveException {
    String myconf;
    SessionState ss = SessionState.get();
    if (ss != null) {
        HiveConf conf = ss.getConf();
        myconf= conf.get("testArg");
        System.out.println("sysout.myconf:"+ myconf);
    }
}

The code is tested on hive 1.2