read file reference storm from hdfs - hadoop

Question

Hi I want to ask something. I've started to learn about apache storm. is it possible to storm to read data file in hdfs.??
example: I have a data txt file in directory /user/hadoop on hdfs. is it possible to storm to read that file.?? thx before
because when I try to running the storm I've an error message if the file does not exist. when I try to run it by read file from my local storage it was successful
>>> Starting to create Topology ...
---> Read Class: FileReaderSpout , 1387957892009
---> Read Class: Split , 1387958291266
---> Read Class: Identity , 247_Identity_1387957902310_1
---> Read Class: SubString , 1387964607853
---> Read Class: Trim , 1387962789262
---> Read Class: SwitchCase , 1387962333010
---> Read Class: Reference , 1387969791518
File /reff/test.txt .. not exists ..

Answer 1

Of course! Here is an example for how to read a file from HDFS:
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
// ...stuff...
FileSystem fs = FileSystem.get(URI.create("hdfs://prodserver"), new Configuration());
String hdfspath = "/apps/storm/conf/config.json";
Path path = new Path();
if (fs.exists(path)) {
InputStreamReader reader = new InputStreamReader(fs.open(path));
// do stuff with the reader
} else {
LOG.info("Does not exist {}", hdfspath);
}
This doesn't use anything specific to storm, just the Hadoop API (hadoop-common.jar).
The error you're getting looks like it is because your file path is incorrect.