Question

在名称为vaidateUser的猪中编写了一个自定义UDF，用于验证用户名。

 public class ValidateUser extends FilterFunc {
       public Boolean exec(Tuple tuple) throws IOException {
           // custom validation code 
       }
 }

该类是默认包的一部分，属于pig_udfs.jar。

此JAR用于猪脚本：validateUsers.pig

 REGISTER 'pig_udfs.jar';

 users = load 'users.txt' using PigStorage(',') as (user:chararray);

 validUsers = filter users by ValidateUser(user);

 dump validUsers;

尝试使用以下方法执行脚本：

 pig -x local validateusers.pig

如下所示获取错误，任何有关解决此问题的意见/建议都将受到赞赏！

Pig Stack Trace：

ERROR 1003: Unable to find an operator for alias fileterd

org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1003: Unable to find an operator for alias fileterd
    at org.apache.pig.PigServer.openIterator(PigServer.java:732)
    at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:615)
    at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:303)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:168)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:144)
    at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:90)
    at org.apache.pig.Main.run(Main.java:500)
    at org.apache.pig.Main.main(Main.java:107)

Answer 1

我没有遇到任何问题custom filter UDF及其工作正常，你能试试吗？在下面的示例中，我将过滤掉所有不等于"test"的名称。

<强> users.txt

test
mike
test
john

<强> PigScript：

REGISTER 'pig_udfs.jar';

users = load 'users.txt' using PigStorage(',') as (user:chararray);
validUsers = filter users by ValidateUser(user);
dump validUsers;

<强> ValidateUser.java

import java.io.IOException;
import org.apache.pig.FilterFunc;
import org.apache.pig.data.Tuple;

public class ValidateUser extends FilterFunc {
        @Override
                public Boolean exec(Tuple input) throws IOException {
                        try {
                                String str = (String)input.get(0);
                                return (!str.equals("test"));
                        }
                        catch (IOException ee) {
                                throw ee;
                        }
                }
}

<强>输出：

(john)
(mike)

确保您已在类路径中设置了piggybank.jar

> javac ValidateUser.java
> jar -cvf pig_udfs.jar ValidateUser.class
> pig -x local validateusers.pig

Apache Pig：UDF：ERROR 1003：无法找到别名fileterd的运算符

1 个答案: