org.apache.hadoop.hive.ql.udf.generic
Class GenericUDFReflect

java.lang.Object
  extended by org.apache.hadoop.hive.ql.udf.generic.GenericUDF
      extended by org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDFReflect
          extended by org.apache.hadoop.hive.ql.udf.generic.GenericUDFReflect
All Implemented Interfaces:
Closeable

public class GenericUDFReflect
extends AbstractGenericUDFReflect

A simple generic udf to call java static functions via reflection.


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF
GenericUDF.DeferredJavaObject, GenericUDF.DeferredObject
 
Constructor Summary
GenericUDFReflect()
           
 
Method Summary
 Object evaluate(GenericUDF.DeferredObject[] arguments)
          Evaluate the GenericUDF with the arguments.
protected  String functionName()
           
 ObjectInspector initialize(ObjectInspector[] arguments)
          Initialize this GenericUDF.
 
Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDFReflect
getDisplayString
 
Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDF
close, configure, getRequiredFiles, getRequiredJars, initializeAndFoldConstants
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

GenericUDFReflect

public GenericUDFReflect()
Method Detail

initialize

public ObjectInspector initialize(ObjectInspector[] arguments)
                           throws UDFArgumentException
Description copied from class: GenericUDF
Initialize this GenericUDF. This will be called once and only once per GenericUDF instance.

Specified by:
initialize in class GenericUDF
Parameters:
arguments - The ObjectInspector for the arguments
Returns:
The ObjectInspector for the return value
Throws:
UDFArgumentException - Thrown when arguments have wrong types, wrong length, etc.

evaluate

public Object evaluate(GenericUDF.DeferredObject[] arguments)
                throws HiveException
Description copied from class: GenericUDF
Evaluate the GenericUDF with the arguments.

Specified by:
evaluate in class GenericUDF
Parameters:
arguments - The arguments as DeferedObject, use DeferedObject.get() to get the actual argument Object. The Objects can be inspected by the ObjectInspectors passed in the initialize call.
Returns:
The
Throws:
HiveException

functionName

protected String functionName()
Specified by:
functionName in class AbstractGenericUDFReflect


Copyright © 2012 The Apache Software Foundation