[MAHOUT-1006] Example from book no longer works - prepare20newsgroups broken with Lucene upgrade

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.7
• Fix Version/s: 0.7
• Assignee: Robin Anil
• Reporter: Ted Dunning
• Created: 03/May/12 18:10
• Updated: 07/Aug/12 17:28
• Resolved: 04/Jun/12 16:39

Description

The StandardAnalyzer from Lucene no longer has a no-args constructor. Our code uses reflection to create this class, but looks for a no-args constructor and that causes this:

./bin/mahout prepare20newsgroups -p 20news-bydate-train/ -o 20news-train/ -a org.apache.lucene.analysis.standard.StandardAnalyzer -c UTF-8  
MAHOUT_LOCAL is not set; adding HADOOP_CONF_DIR to classpath.
no HADOOP_HOME set, running locally
Unable to find a $JAVA_HOME at "/usr", continuing with system-provided Java...
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/Users/hadoop/mahout/examples/target/mahout-examples-0.7-SNAPSHOT-job.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/Users/hadoop/mahout/examples/target/dependency/slf4j-jcl-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/Users/hadoop/mahout/examples/target/dependency/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Exception in thread "main" java.lang.IllegalStateException: java.lang.NoSuchMethodException: org.apache.lucene.analysis.standard.StandardAnalyzer.<init>()
	at org.apache.mahout.common.ClassUtils.instantiateAs(ClassUtils.java:68)
	at org.apache.mahout.common.ClassUtils.instantiateAs(ClassUtils.java:28)
	at org.apache.mahout.classifier.bayes.PrepareTwentyNewsgroups.main(PrepareTwentyNewsgroups.java:89)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
	at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
	at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:188)
Caused by: java.lang.NoSuchMethodException: org.apache.lucene.analysis.standard.StandardAnalyzer.<init>()
	at java.lang.Class.getConstructor0(Class.java:2706)
	at java.lang.Class.getConstructor(Class.java:1657)
	at org.apache.mahout.common.ClassUtils.instantiateAs(ClassUtils.java:62)
	... 9 more

This is really bad.