GIRAPH-1245

closes #136
diff --git a/giraph-block-app/src/main/java/org/apache/giraph/block_app/framework/output/BlockOutputHandle.java b/giraph-block-app/src/main/java/org/apache/giraph/block_app/framework/output/BlockOutputHandle.java
index a16963d..07243eb 100644
--- a/giraph-block-app/src/main/java/org/apache/giraph/block_app/framework/output/BlockOutputHandle.java
+++ b/giraph-block-app/src/main/java/org/apache/giraph/block_app/framework/output/BlockOutputHandle.java
@@ -51,11 +51,11 @@
       Progressable hadoopProgressable) {
     outputDescMap = BlockOutputFormat.createInitAndCheckOutputDescsMap(
         conf, jobIdentifier);
-    for (String confOption : outputDescMap.keySet()) {
-      outputDescMap.get(confOption).preWriting();
-      freeWriters.put(confOption,
+    for (Map.Entry<String, BlockOutputDesc> entry : outputDescMap.entrySet()) {
+      entry.getValue().preWriting();
+      freeWriters.put(entry.getKey(),
           new ConcurrentLinkedQueue<BlockOutputWriter>());
-      occupiedWriters.put(confOption,
+      occupiedWriters.put(entry.getKey(),
           new ConcurrentLinkedQueue<BlockOutputWriter>());
     }
     initialize(conf, hadoopProgressable);
diff --git a/pom.xml b/pom.xml
index c02c1fa..bf5b6e8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -776,7 +776,7 @@
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>findbugs-maven-plugin</artifactId>
-          <version>3.0.0</version>
+          <version>3.0.4</version>
           <configuration>
             <xmlOutput>true</xmlOutput>
             <findbugsXmlOutput>false</findbugsXmlOutput>