From 3e8e279606e195d5a9c33356592cb9ac31c031af Mon Sep 17 00:00:00 2001
From: Mahadev Konar <mahadev@apache.org>
Date: Sun, 4 Dec 2011 20:00:08 +0000
Subject: [PATCH] MAPREDUCE-3458. Fix findbugs warnings in hadoop-examples.
 (Devaraj K via mahadev) - Merging r1210190 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1210191 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-mapreduce-project/CHANGES.txt          |  3 +
 .../dev-support/findbugs-exclude.xml          | 63 +++++++++++++++++++
 .../hadoop-mapreduce-examples/pom.xml         | 16 +++++
 .../java/org/apache/hadoop/examples/Join.java | 15 +++--
 .../hadoop/examples/dancing/Pentomino.java    |  2 +-
 .../hadoop/examples/terasort/TeraGen.java     |  2 +-
 .../examples/terasort/TeraInputFormat.java    | 31 +++++++--
 .../hadoop/examples/terasort/TeraSort.java    |  8 ++-
 8 files changed, 128 insertions(+), 12 deletions(-)
 create mode 100644 hadoop-mapreduce-project/hadoop-mapreduce-examples/dev-support/findbugs-exclude.xml

diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index 87e41223396..76325478507 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -188,6 +188,9 @@ Release 0.23.1 - Unreleased
     MAPREDUCE-3456. $HADOOP_PREFIX/bin/yarn should set defaults for 
     $HADOOP_*_HOME (Eric Payne via mahadev)
 
+    MAPREDUCE-3458. Fix findbugs warnings in hadoop-examples. (Devaraj K
+    via mahadev)
+
 Release 0.23.0 - 2011-11-01 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/dev-support/findbugs-exclude.xml b/hadoop-mapreduce-project/hadoop-mapreduce-examples/dev-support/findbugs-exclude.xml
new file mode 100644
index 00000000000..244adafebdc
--- /dev/null
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/dev-support/findbugs-exclude.xml
@@ -0,0 +1,63 @@
+<!--
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+-->
+
+<FindBugsFilter>
+
+ <!-- Ignore some irrelevant serialization warnings -->
+  <Match>
+    <Class name="org.apache.hadoop.examples.SecondarySort$FirstGroupingComparator" />
+    <Bug pattern="SE_COMPARATOR_SHOULD_BE_SERIALIZABLE" />
+  </Match>
+
+  <Match>
+    <Class name="org.apache.hadoop.examples.SecondarySort$IntPair$Comparator" />
+    <Bug pattern="SE_COMPARATOR_SHOULD_BE_SERIALIZABLE" />
+  </Match>
+
+
+ <!-- Ignore the irrelevant resource cleanup warnings-->
+  <Match>
+    <Class name="org.apache.hadoop.examples.DBCountPageView" />
+    <Method name="verify" />
+    <Bug pattern="OBL_UNSATISFIED_OBLIGATION" />
+  </Match>
+
+ <!-- Ignore the irrelevant closure warnings-->
+  <Match>
+    <Class name="org.apache.hadoop.examples.dancing.Pentomino$Piece" />
+    <Bug pattern="EI_EXPOSE_REP2" />
+  </Match>
+
+  <!-- Ignore the irrelevant package protection warnings-->
+  <Match>
+    <Class name="org.apache.hadoop.examples.dancing.Pentomino" />
+     <Or>
+      <Field name="fourRotations" />
+      <Field name="oneRotation" />
+      <Field name="twoRotations" />
+     </Or>
+    <Bug pattern="MS_PKGPROTECT" />
+  </Match>
+
+   <!-- Ignore the irrelevant right shift warnings, as only positive integers are given as input-->
+  <Match>
+    <Class name="org.apache.hadoop.examples.terasort.Unsigned16" />
+    <Method name="getHexDigit" />
+    <Bug pattern="ICAST_QUESTIONABLE_UNSIGNED_RIGHT_SHIFT" />
+  </Match>
+
+</FindBugsFilter>
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/pom.xml b/hadoop-mapreduce-project/hadoop-mapreduce-examples/pom.xml
index 4f54c4c1de2..86885c5c6e3 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/pom.xml
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/pom.xml
@@ -27,6 +27,10 @@
   <name>Apache Hadoop MapReduce Examples</name>
   <packaging>jar</packaging>
 
+  <properties>
+    <mr.examples.basedir>${basedir}</mr.examples.basedir>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.hadoop</groupId>
@@ -59,6 +63,18 @@
        </archive>
      </configuration>
     </plugin>
+
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>findbugs-maven-plugin</artifactId>
+         <configuration>
+          <findbugsXmlOutput>true</findbugsXmlOutput>
+          <xmlOutput>true</xmlOutput>
+          <excludeFilterFile>${mr.examples.basedir}/dev-support/findbugs-exclude.xml</excludeFilterFile>
+          <effort>Max</effort>
+        </configuration>
+      </plugin>
+
    </plugins>
    </build>
 </project>
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/Join.java b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/Join.java
index 86a13ad0ca2..2063d04655a 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/Join.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/Join.java
@@ -19,7 +19,9 @@
 package org.apache.hadoop.examples;
 
 import java.io.IOException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
@@ -29,9 +31,14 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
 import org.apache.hadoop.mapred.ClusterStatus;
 import org.apache.hadoop.mapred.JobClient;
-import org.apache.hadoop.mapreduce.*;
+import org.apache.hadoop.mapreduce.InputFormat;
+import org.apache.hadoop.mapreduce.Job;
+import org.apache.hadoop.mapreduce.Mapper;
+import org.apache.hadoop.mapreduce.OutputFormat;
+import org.apache.hadoop.mapreduce.Reducer;
 import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
-import org.apache.hadoop.mapreduce.lib.join.*;
+import org.apache.hadoop.mapreduce.lib.join.CompositeInputFormat;
+import org.apache.hadoop.mapreduce.lib.join.TupleWritable;
 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
 import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
 import org.apache.hadoop.util.Tool;
@@ -52,7 +59,7 @@ import org.apache.hadoop.util.ToolRunner;
  *            [<i>in-dir</i>]* <i>in-dir</i> <i>out-dir</i> 
  */
 public class Join extends Configured implements Tool {
-  public static String REDUCES_PER_HOST = "mapreduce.join.reduces_per_host";
+  public static final String REDUCES_PER_HOST = "mapreduce.join.reduces_per_host";
   static int printUsage() {
     System.out.println("join [-r <reduces>] " +
                        "[-inFormat <input format class>] " +
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/dancing/Pentomino.java b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/dancing/Pentomino.java
index 3b8759a9774..5e636b901e7 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/dancing/Pentomino.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/dancing/Pentomino.java
@@ -69,7 +69,7 @@ public class Pentomino {
     }
     
     public int[] getRotations() {
-      return rotations;
+      return rotations.clone();
     }
     
     public boolean getFlippable() {
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraGen.java b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraGen.java
index ec99c19bc44..9880d54003e 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraGen.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraGen.java
@@ -70,7 +70,7 @@ public class TeraGen extends Configured implements Tool {
 
   public static enum Counters {CHECKSUM}
 
-  public static String NUM_ROWS = "mapreduce.terasort.num-rows";
+  public static final String NUM_ROWS = "mapreduce.terasort.num-rows";
   /**
    * An input format that assigns ranges of longs to each mapper.
    */
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraInputFormat.java b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraInputFormat.java
index a381aba913f..4ef0033012f 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraInputFormat.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraInputFormat.java
@@ -156,10 +156,10 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
    * them and picks N-1 keys to generate N equally sized partitions.
    * @param job the job to sample
    * @param partFile where to write the output file to
-   * @throws IOException if something goes wrong
+   * @throws Throwable if something goes wrong
    */
   public static void writePartitionFile(final JobContext job, 
-      Path partFile) throws IOException, InterruptedException  {
+      Path partFile) throws Throwable  {
     long t1 = System.currentTimeMillis();
     Configuration conf = job.getConfiguration();
     final TeraInputFormat inFormat = new TeraInputFormat();
@@ -174,11 +174,12 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
     final long recordsPerSample = sampleSize / samples;
     final int sampleStep = splits.size() / samples;
     Thread[] samplerReader = new Thread[samples];
+    SamplerThreadGroup threadGroup = new SamplerThreadGroup("Sampler Reader Thread Group");
     // take N samples from different parts of the input
     for(int i=0; i < samples; ++i) {
       final int idx = i;
       samplerReader[i] = 
-        new Thread ("Sampler Reader " + idx) {
+        new Thread (threadGroup,"Sampler Reader " + idx) {
         {
           setDaemon(true);
         }
@@ -201,7 +202,7 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
           } catch (IOException ie){
             System.err.println("Got an exception while reading splits " +
                 StringUtils.stringifyException(ie));
-            System.exit(-1);
+            throw new RuntimeException(ie);
           } catch (InterruptedException e) {
         	  
           }
@@ -215,6 +216,9 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
     for (int i = 0; i < samples; i++) {
       try {
         samplerReader[i].join();
+        if(threadGroup.getThrowable() != null){
+          throw threadGroup.getThrowable();
+        }
       } catch (InterruptedException e) {
       }
     }
@@ -225,6 +229,25 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
     long t3 = System.currentTimeMillis();
     System.out.println("Computing parititions took " + (t3 - t2) + "ms");
   }
+  
+  static class SamplerThreadGroup extends ThreadGroup{
+
+    private Throwable throwable;
+
+    public SamplerThreadGroup(String s) {
+      super(s);
+    }
+    
+    @Override
+    public void uncaughtException(Thread thread, Throwable throwable) {
+      this.throwable = throwable;
+    }
+    
+    public Throwable getThrowable() {
+      return this.throwable;
+    }
+    
+  }
 
   static class TeraRecordReader extends RecordReader<Text,Text> {
     private FSDataInputStream in;
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraSort.java b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraSort.java
index 2ce8155b476..7daa3016c21 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraSort.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-examples/src/main/java/org/apache/hadoop/examples/terasort/TeraSort.java
@@ -31,7 +31,6 @@ import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.Text;
-import org.apache.hadoop.mapreduce.Cluster;
 import org.apache.hadoop.mapreduce.Job;
 import org.apache.hadoop.mapreduce.JobContext;
 import org.apache.hadoop.mapreduce.MRJobConfig;
@@ -300,7 +299,12 @@ public class TeraSort extends Configured implements Tool {
                                     TeraInputFormat.PARTITION_FILENAME);
       URI partitionUri = new URI(partitionFile.toString() +
                                  "#" + TeraInputFormat.PARTITION_FILENAME);
-      TeraInputFormat.writePartitionFile(job, partitionFile);
+      try {
+        TeraInputFormat.writePartitionFile(job, partitionFile);
+      } catch (Throwable e) {
+        LOG.error(e.getMessage());
+        return -1;
+      }
       job.addCacheFile(partitionUri);
       job.createSymlink();    
       long end = System.currentTimeMillis();