org.apache.hadoop.hive.ql.exec
Class ExprNodeFieldEvaluator

java.lang.Object
  extended by org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator
      extended by org.apache.hadoop.hive.ql.exec.ExprNodeFieldEvaluator

public class ExprNodeFieldEvaluator
extends ExprNodeEvaluator

This Evaluator can evaluate s.f for s as both struct and list of struct. If s is struct, then s.f is the field. If s is list of struct, then s.f is the list of struct field.


Field Summary
protected  ExprNodeFieldDesc desc
           
 
Constructor Summary
ExprNodeFieldEvaluator(ExprNodeFieldDesc desc)
           
 
Method Summary
 Object evaluate(Object row)
          Evaluate the expression given the row.
 ObjectInspector initialize(ObjectInspector rowInspector)
          Initialize should be called once and only once.
 
Methods inherited from class org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator
isDeterministic
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

desc

protected ExprNodeFieldDesc desc
Constructor Detail

ExprNodeFieldEvaluator

public ExprNodeFieldEvaluator(ExprNodeFieldDesc desc)
Method Detail

initialize

public ObjectInspector initialize(ObjectInspector rowInspector)
                           throws HiveException
Description copied from class: ExprNodeEvaluator
Initialize should be called once and only once. Return the ObjectInspector for the return value, given the rowInspector.

Specified by:
initialize in class ExprNodeEvaluator
Throws:
HiveException

evaluate

public Object evaluate(Object row)
                throws HiveException
Description copied from class: ExprNodeEvaluator
Evaluate the expression given the row. This method should use the rowInspector passed in from initialize to inspect the row object. The return value will be inspected by the return value of initialize.

Specified by:
evaluate in class ExprNodeEvaluator
Throws:
HiveException


Copyright © 2011 The Apache Software Foundation