Pig UDF中的分布式缓存(Distributed Cache in Pig UDF)

这是我使用Pig使用分布式缓存实现UDF的代码。

public class Regex extends EvalFunc<Integer> { static HashMap<String, String> map = new HashMap<String, String>(); public List<String> getCacheFiles() { Path lookup_file = new Path( "hdfs://localhost.localdomain:8020/user/cloudera/top"); List<String> list = new ArrayList<String>(1); list.add(lookup_file + "#id_lookup"); return list; } public void VectorizeData() throws IOException { FileReader fr = new FileReader("./id_lookup"); BufferedReader brd = new BufferedReader(fr); String line; while ((line = brd.readLine()) != null) { String str[] = line.split("#"); map.put(str[0], str[1]); } fr.close(); } @Override public Integer exec(Tuple input) throws IOException { // TODO Auto-generated method stub return map.size(); } }

鉴于以下是我的分布式缓存输入文件（hdfs：//localhost.localdomain：8020 / user / cloudera / top）

Impetigo|Streptococcus pyogenes#Impetigo indeterminate leprosy|Uncharacteristic leprosy#indeterminate leprosy

我得到的输出是

(0) (0) (0) (0) (0)

这意味着我的hashmap为空。如何使用分布式缓存填充我的hashmap？

Here is my code to Implement a UDF using Distributed Cache Using Pig.

public class Regex extends EvalFunc<Integer> { static HashMap<String, String> map = new HashMap<String, String>(); public List<String> getCacheFiles() { Path lookup_file = new Path( "hdfs://localhost.localdomain:8020/user/cloudera/top"); List<String> list = new ArrayList<String>(1); list.add(lookup_file + "#id_lookup"); return list; } public void VectorizeData() throws IOException { FileReader fr = new FileReader("./id_lookup"); BufferedReader brd = new BufferedReader(fr); String line; while ((line = brd.readLine()) != null) { String str[] = line.split("#"); map.put(str[0], str[1]); } fr.close(); } @Override public Integer exec(Tuple input) throws IOException { // TODO Auto-generated method stub return map.size(); } }

Given Below is my Distributed Cache Input File (hdfs://localhost.localdomain:8020/user/cloudera/top)

Impetigo|Streptococcus pyogenes#Impetigo indeterminate leprosy|Uncharacteristic leprosy#indeterminate leprosy

Output I get is

(0) (0) (0) (0) (0)

This means that my hashmap is empty. How do i fill my hashmap using Distributed Cache?.