diff --git a/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene40/Lucene40CompoundFormat.java b/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene40/Lucene40CompoundFormat.java
index 2c41d8cbe52..dfae90fb721 100644
--- a/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene40/Lucene40CompoundFormat.java
+++ b/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene40/Lucene40CompoundFormat.java
@@ -33,6 +33,10 @@ import org.apache.lucene.store.IOContext;
  */
 @Deprecated
 public final class Lucene40CompoundFormat extends CompoundFormat {
+  
+  /** Sole constructor. */
+  public Lucene40CompoundFormat() {
+  }
 
   @Override
   public Directory getCompoundReader(Directory dir, SegmentInfo si, IOContext context) throws IOException {
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextCompoundFormat.java b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextCompoundFormat.java
index d6495979493..81f8f4d95e4 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextCompoundFormat.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextCompoundFormat.java
@@ -49,6 +49,10 @@ import org.apache.lucene.util.StringHelper;
  * @lucene.experimental
  */
 public class SimpleTextCompoundFormat extends CompoundFormat {
+  
+  /** Sole constructor. */
+  public SimpleTextCompoundFormat() {
+  }
 
   @Override
   public Directory getCompoundReader(Directory dir, SegmentInfo si, IOContext context) throws IOException {
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/CompoundFormat.java b/lucene/core/src/java/org/apache/lucene/codecs/CompoundFormat.java
index e3943bacb28..29556305667 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/CompoundFormat.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/CompoundFormat.java
@@ -49,7 +49,10 @@ public abstract class CompoundFormat {
    */
   // TODO: get checkAbort out of here, and everywhere, and have iw do it at a higher level
   public abstract void write(Directory dir, SegmentInfo si, Collection<String> files, CheckAbort checkAbort, IOContext context) throws IOException;
-  
+
+  /**
+   * Returns the compound file names used by this segment.
+   */
   // TODO: get this out of here, and use trackingdirwrapper. but this is really scary in IW right now...
   // NOTE: generally si.useCompoundFile is not even yet 'set' when this is called.
   public abstract String[] files(SegmentInfo si);
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundFormat.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundFormat.java
index d24623403f7..aa196d533c8 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundFormat.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundFormat.java
@@ -63,6 +63,10 @@ import org.apache.lucene.store.IndexOutput;
  */
 public final class Lucene50CompoundFormat extends CompoundFormat {
 
+  /** Sole constructor. */
+  public Lucene50CompoundFormat() {
+  }
+  
   @Override
   public Directory getCompoundReader(Directory dir, SegmentInfo si, IOContext context) throws IOException {
     return new Lucene50CompoundReader(dir, si, context);
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/package.html b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/package.html
index 30e269f979f..9ce0a294e2f 100755
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/package.html
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/package.html
@@ -243,7 +243,7 @@ file.</td>
 <td>Stores metadata about a segment</td>
 </tr>
 <tr>
-<td>{@link org.apache.lucene.codecs.lucene50.LUcene50CompoundFormat Compound File}</td>
+<td>{@link org.apache.lucene.codecs.lucene50.Lucene50CompoundFormat Compound File}</td>
 <td>.cfs, .cfe</td>
 <td>An optional "virtual" file consisting of all the other index files for
 systems that frequently run out of file handles.</td>