PDFBOX-5660: optimize, as suggested by Valery Bokov; DRY refactoring; closes #330

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1929759 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdfparser/BruteForceParser.java

@@ -21,6 +21,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
@@ -307,14 +308,15 @@ protected void bfSearchForObjStreams(Map<COSObjectKey, Long> xrefTable) throws I
 
         Map<Long, COSObjectKey> bfSearchForObjStreamOffsets = bfSearchForObjStreamOffsets();
         Map<COSObjectKey, Long> bfCOSObjectOffsets = getBFCOSObjectOffsets();
+        Set<Entry<Long, COSObjectKey>> entries = bfSearchForObjStreamOffsets.entrySet();
         // log warning about skipped stream
-        bfSearchForObjStreamOffsets.entrySet().stream() //
+        entries.stream() //
                 .filter(o -> bfCOSObjectOffsets.get(o.getValue()) == null) //
                 .forEach(o -> LOG.warn("Skipped incomplete object stream:{} at {}", o.getValue(),
                         o.getKey()));
 
         // collect all stream offsets
-        List<Long> objStreamOffsets = bfSearchForObjStreamOffsets.entrySet().stream() //
+        List<Long> objStreamOffsets = entries.stream() //
                 .filter(o -> bfCOSObjectOffsets.get(o.getValue()) != null) //
                 .filter(o -> o.getKey().equals(bfCOSObjectOffsets.get(o.getValue()))) //
                 .map(Map.Entry::getKey) //