The only hook in frontend for a UDF is outputSchema. You can put your
property into UDFContext in outputSchema, and read back in exec.
public String exec(Tuple input) throws IOException {
UDFContext context = UDFContext.getUDFContext();
String a =
context.getUDFProperties(this.getClass()).getProperty("Hello");
return a;
}
public Schema outputSchema(Schema input) {
UDFContext context = UDFContext.getUDFContext();
context.getUDFProperties(this.getClass()).setProperty("Hello",
"World");
return null;
}
The other option is to provide a system wide configuration in command
line (-D), or pig.properties, which can be retrieved in UDF.exec using:
UDFContext.getUDFContext().getJobConf().get("propertyname")
Daniel
Dexin Wang wrote:
Hi all,
I was reading this:
http://pig.apache.org/docs/r0.7.0/udf.html#Passing+Configurations+to+UDFs
It sounded like I can pass some configuration or context to the UDF but I
can't figure out how I would do that after I searched quite a bit on
internet and past discussion.
In my UDF, I can also do this:
UDFContext context = UDFContext.getUDFContext();
Properties properties =
context.getUDFProperties(this.getClass());
so if the context is set on the front end, supposedly, it will be in that
properties object. But how do I set it on the front end or whichever way to
pass it to UDF?
Thanks!
Dexin
