#1 ClassCastException:LongWritable cannot be cast to Text

[Dieter Plaetinck]

using the latest mirex from svn.
using hadoop 1.0 (also reproduceable with hadoop 0.20.2), when running the anchor text extraction, I get this error:

java.lang.ClassCastException: org.apache.hadoop.io.LongWritable cannot be cast to org.apache.hadoop.io.Text
at nl.utwente.mirex.AnchorExtract$Map.map(Unknown Source)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1083)
at org.apache.hadoop.mapred.Child.main(Child.java:249)

[Dieter Plaetinck]

This fix seems to work:

diff --git a/src/nl/utwente/mirex/AnchorExtract.java b/src/nl/utwente/mirex/AnchorExtract.java
index 5b7b41e..1094b50 100644
--- a/src/nl/utwente/mirex/AnchorExtract.java
+++ b/src/nl/utwente/mirex/AnchorExtract.java
@@ -27,6 +27,7 @@ import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.GzipCodec;
import org.apache.hadoop.mapreduce.Job;
@@ -71,7 +72,7 @@ public class AnchorExtract {
/**
* -- Mapper: Extracts anchors.
*/
- public static class Map extends Mapper<Text, WritableWarcRecord, Text, Text> {
+ public static class Map extends Mapper<LongWritable, WritableWarcRecord, Text, Text> {
//public static class Map extends MapReduceBase implements Mapper<LongWritable, WritableWarcRecord, Text, Text> {

private final static Pattern
@@ -103,7 +104,7 @@ public class AnchorExtract {
* @param value the web page
* @param output (URL, anchor text <i>or</i> TREC-ID)
*/
- public void map(Text key, WritableWarcRecord value, Context context)
+ public void map(LongWritable key, WritableWarcRecord value, Context context)
throws IOException, InterruptedException {
String baseUri, trecId, content;
Text link = new Text(), anchor = new Text();