我对pig是个新手,我正在尝试创建一个udf,它获取一个元组并基于分隔符返回多个元组。所以我写了一个udf来读取下面的数据文件
2012/01/01 Name1 Category1|Category2|Category3
2012/01/01 Name2 Category2|Category3
2012/01/01 Name3 Category1|Category5
基本上我是想读2美元的领域
Category1|Category2|Category3
Category2|Category3
Category1|Category5
获取输出为:-
Category1, Category2, Category3
Category2, Category3
Category1, Category5
下面是我写的自定义项代码。。
package com.test.multipleTuple;
import java.io.IOException;
import org.apache.pig.EvalFunc;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
public class TupleToMultipleTuple extends EvalFunc<String> {
@Override
public String exec(Tuple input) throws IOException {
// Keep the count of every cell in the
Tuple aux = TupleFactory.getInstance().newTuple();
if (input == null || input.size() == 0)
return null;
try {
String del = "\\|";
String str = (String) input.get(0);
String field[] = str.split(del);
for (String nxt : field) {
aux.append(nxt.trim().toString());
}
} catch (Exception e) {
throw new IOException("Caught exception processing input row ", e);
}
return aux.toDelimitedString(",");
}
}
创建jar--> TupleToMultipleTuple.jar
但是我在执行它时得到了下面的错误。
Pig Stack Trace
---------------
ERROR 1066: Unable to open iterator for alias B
org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable to open iterator for alias B
at org.apache.pig.PigServer.openIterator(PigServer.java:892)
at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:774)
at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:372)
at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:198)
at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:173)
at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:69)
at org.apache.pig.Main.run(Main.java:547)
at org.apache.pig.Main.main(Main.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
Caused by: java.io.IOException: Job terminated with anomalous status FAILED
at org.apache.pig.PigServer.openIterator(PigServer.java:884)
... 13 more
你能帮我纠正这个问题吗。谢谢。
应用自定义项的pig脚本。。
REGISTER TupleToMultipleTuple.jar;
DEFINE myFunc com.test.multipleTuple.TupleToMultipleTuple();
A = load 'data.txt' USING PigStorage(' ');
B = foreach A generate myFunc($2);
dump B;
2条答案
按热度按时间wtzytmuj1#
找到问题。。将dayabytearray解析为字符串时出现问题。。用于修复字符串()
wfveoks02#
您可以像这样使用内置的拆分功能:
你会得到3个元组
cat1
,cat2
以及cat2
键入为chararray
并由它们所属关系的当前分隔符分隔。