com.aliyun.odps.udf

Class UDF

java.lang.Object

com.aliyun.odps.udf.UDF

All Implemented Interfaces:

ContextFunction

public class UDF
extends Object
implements ContextFunction

UDF 基类 UDF (User Defined Scalar Function) 自定义函数，其输入输出是一对一的关系，即读入一行数据，写出一条输出值。

自定义 UDF 需要继承这个类来实现一个 UDF，并根据输入输出类型编写 evaluate 方法。

例如:

   public class MyPlus extends UDF {
     Long evaluate(Long a, Long b) {
       if (a == null || b == null) {
         return null;
       }
       return a + b;
     }
   }
 

Constructor Summary

Constructors

Constructor and Description
UDF()

Method Summary

Modifier and Type	Method and Description
void	close()
void	setup(ExecutionContext ctx)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UDF

public UDF()

Method Detail

setup

public void setup(ExecutionContext ctx)
           throws UDFException,
                  IOException

Specified by:

setup in interface ContextFunction

Throws:

UDFException

IOException

close

public void close()
           throws UDFException,
                  IOException

Specified by:

close in interface ContextFunction

Throws:

UDFException

IOException