LUCENE-818: throw AlreadyClosedException when accessing IndexWriter, *Reader, RAMDirectory and FieldsReader after close()

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@518262 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -29,6 +29,11 @@ API Changes
     share an index over NFS by customizing when prior commits are
     deleted. (Mike McCandless)
 
+ 4. LUCENE-818: changed most public methods of IndexWriter,
+    IndexReader (and its subclasses), FieldsReader and RAMDirectory to
+    throw AlreadyClosedException if they are accessed after being
+    closed.  (Mike McCandless)
+
 Bug fixes
 
  1. LUCENE-804: Fixed build.xml to pack a fully compilable src dist.  (Doron Cohen)

src/java/org/apache/lucene/index/FieldsReader.java

@@ -20,6 +20,7 @@ package org.apache.lucene.index;
 import org.apache.lucene.document.*;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.AlreadyClosedException;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -46,6 +47,7 @@ final class FieldsReader {
 
   private final IndexInput indexStream;
   private int size;
+  private boolean closed;
 
   private ThreadLocal fieldsStreamTL = new ThreadLocal();
 
@@ -58,6 +60,15 @@ final class FieldsReader {
     size = (int) (indexStream.length() / 8);
   }
 
+  /**
+   * @throws AlreadyClosedException if this FieldsReader is closed
+   */
+  protected final void ensureOpen() throws AlreadyClosedException {
+    if (closed) {
+      throw new AlreadyClosedException("this FieldsReader is closed");
+    }
+  }
+
   /**
    * Closes the underlying {@link org.apache.lucene.store.IndexInput} streams, including any ones associated with a
    * lazy implementation of a Field.  This means that the Fields values will not be accessible.
@@ -65,6 +76,7 @@ final class FieldsReader {
    * @throws IOException
    */
   final void close() throws IOException {
+    if (!closed) {
       fieldsStream.close();
       cloneableFieldsStream.close();
       indexStream.close();
@@ -73,6 +85,8 @@ final class FieldsReader {
         localFieldsStream.close();
         fieldsStreamTL.set(null);
       }
+      closed = true;
+    }
   }
 
   final int size() {
@@ -323,6 +337,7 @@ final class FieldsReader {
      * binaryValue() must be set.
      */
     public byte[] binaryValue() {
+      ensureOpen();
       if (fieldsData == null) {
         final byte[] b = new byte[toRead];
         IndexInput localFieldsStream = getFieldStream();
@@ -349,6 +364,7 @@ final class FieldsReader {
      * and binaryValue() must be set.
      */
     public Reader readerValue() {
+      ensureOpen();
       return fieldsData instanceof Reader ? (Reader) fieldsData : null;
     }
 
@@ -358,6 +374,7 @@ final class FieldsReader {
      * binaryValue() must be set.
      */
     public String stringValue() {
+      ensureOpen();
       if (fieldsData == null) {
         IndexInput localFieldsStream = getFieldStream();
         try {
@@ -380,18 +397,22 @@ final class FieldsReader {
     }
 
     public long getPointer() {
+      ensureOpen();
       return pointer;
     }
 
     public void setPointer(long pointer) {
+      ensureOpen();
       this.pointer = pointer;
     }
 
     public int getToRead() {
+      ensureOpen();
       return toRead;
     }
 
     public void setToRead(int toRead) {
+      ensureOpen();
       this.toRead = toRead;
     }
   }

src/java/org/apache/lucene/index/FilterIndexReader.java

@@ -92,43 +92,84 @@ public class FilterIndexReader extends IndexReader {
 
   public TermFreqVector[] getTermFreqVectors(int docNumber)
           throws IOException {
+    ensureOpen();
     return in.getTermFreqVectors(docNumber);
   }
 
   public TermFreqVector getTermFreqVector(int docNumber, String field)
           throws IOException {
+    ensureOpen();
     return in.getTermFreqVector(docNumber, field);
   }
 
-  public int numDocs() { return in.numDocs(); }
+  public int numDocs() {
-  public int maxDoc() { return in.maxDoc(); }
+    // Don't call ensureOpen() here (it could affect performance)
+    return in.numDocs();
+  }
 
-  public Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException { return in.document(n, fieldSelector); }
+  public int maxDoc() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return in.maxDoc();
+  }
+
+  public Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
+    ensureOpen();
+    return in.document(n, fieldSelector);
+  }
+
+  public boolean isDeleted(int n) {
+    // Don't call ensureOpen() here (it could affect performance)
+    return in.isDeleted(n);
+  }
+
+  public boolean hasDeletions() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return in.hasDeletions();
+  }
 
-  public boolean isDeleted(int n) { return in.isDeleted(n); }
-  public boolean hasDeletions() { return in.hasDeletions(); }
   protected void doUndeleteAll() throws CorruptIndexException, IOException {in.undeleteAll();}
 
   public boolean hasNorms(String field) throws IOException {
+    ensureOpen();
     return in.hasNorms(field);
   }
 
-  public byte[] norms(String f) throws IOException { return in.norms(f); }
+  public byte[] norms(String f) throws IOException {
+    ensureOpen();
+    return in.norms(f);
+  }
+
   public void norms(String f, byte[] bytes, int offset) throws IOException {
+    ensureOpen();
     in.norms(f, bytes, offset);
   }
+
   protected void doSetNorm(int d, String f, byte b) throws CorruptIndexException, IOException {
     in.setNorm(d, f, b);
   }
 
-  public TermEnum terms() throws IOException { return in.terms(); }
+  public TermEnum terms() throws IOException {
-  public TermEnum terms(Term t) throws IOException { return in.terms(t); }
+    ensureOpen();
+    return in.terms();
+  }
 
-  public int docFreq(Term t) throws IOException { return in.docFreq(t); }
+  public TermEnum terms(Term t) throws IOException {
+    ensureOpen();
+    return in.terms(t);
+  }
 
-  public TermDocs termDocs() throws IOException { return in.termDocs(); }
+  public int docFreq(Term t) throws IOException {
+    ensureOpen();
+    return in.docFreq(t);
+  }
+
+  public TermDocs termDocs() throws IOException {
+    ensureOpen();
+    return in.termDocs();
+  }
 
   public TermPositions termPositions() throws IOException {
+    ensureOpen();
     return in.termPositions();
   }
 
@@ -138,9 +179,17 @@ public class FilterIndexReader extends IndexReader {
 
 
   public Collection getFieldNames(IndexReader.FieldOption fieldNames) {
+    ensureOpen();
     return in.getFieldNames(fieldNames);
   }
 
-  public long getVersion() { return in.getVersion(); }
+  public long getVersion() {
-  public boolean isCurrent() throws CorruptIndexException, IOException { return in.isCurrent(); }
+    ensureOpen();
+    return in.getVersion();
+  }
+
+  public boolean isCurrent() throws CorruptIndexException, IOException {
+    ensureOpen();
+    return in.isCurrent();
+  }
 }

src/java/org/apache/lucene/index/IndexReader.java

@@ -25,6 +25,7 @@ import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockObtainFailedException;
+import org.apache.lucene.store.AlreadyClosedException;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -115,7 +116,16 @@ public abstract class IndexReader {
   private boolean directoryOwner;
   private boolean closeDirectory;
   private IndexDeletionPolicy deletionPolicy;
-  private boolean isClosed;
+  private boolean closed;
+
+  /**
+   * @throws AlreadyClosedException if this IndexReader is closed
+   */
+  protected final void ensureOpen() throws AlreadyClosedException {
+    if (closed) {
+      throw new AlreadyClosedException("this IndexReader is closed");
+    }
+  }
 
   private SegmentInfos segmentInfos;
   private Lock writeLock;
@@ -208,8 +218,12 @@ public abstract class IndexReader {
     }.run();
   }
 
-  /** Returns the directory this index resides in. */
+  /** Returns the directory this index resides in.
-  public Directory directory() { return directory; }
+   */
+  public Directory directory() {
+    ensureOpen();
+    return directory;
+  }
 
   /**
    * Returns the time the index in the named directory was last modified.
@@ -301,6 +315,7 @@ public abstract class IndexReader {
    * Version number when this IndexReader was opened.
    */
   public long getVersion() {
+    ensureOpen();
     return segmentInfos.getVersion();
   }
 
@@ -313,6 +328,7 @@ public abstract class IndexReader {
    * @throws IOException if there is a low-level IO error
    */
   public boolean isCurrent() throws CorruptIndexException, IOException {
+    ensureOpen();
     return SegmentInfos.readCurrentVersion(directory) == segmentInfos.getVersion();
   }
 
@@ -321,6 +337,7 @@ public abstract class IndexReader {
    * @return <code>true</code> if the index is optimized; <code>false</code> otherwise
    */
   public boolean isOptimized() {
+    ensureOpen();
     return segmentInfos.size() == 1 && hasDeletions() == false;
   }
 
@@ -407,6 +424,7 @@ public abstract class IndexReader {
    * @throws IOException if there is a low-level IO error
    */
   public Document document(int n) throws CorruptIndexException, IOException {
+    ensureOpen();
     return document(n, null);
   }
 
@@ -445,6 +463,7 @@ public abstract class IndexReader {
   public boolean hasNorms(String field) throws IOException {
     // backward compatible implementation.
     // SegmentReader has an efficient implementation.
+    ensureOpen();
     return norms(field) != null;
   }
 
@@ -477,11 +496,11 @@ public abstract class IndexReader {
    * @throws LockObtainFailedException if another writer
    *  has this index open (<code>write.lock</code> could not
    *  be obtained)
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public final synchronized  void setNorm(int doc, String field, byte value)
           throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     if(directoryOwner)
       acquireWriteLock();
     hasChanges = true;
@@ -504,27 +523,31 @@ public abstract class IndexReader {
    * @throws LockObtainFailedException if another writer
    *  has this index open (<code>write.lock</code> could not
    *  be obtained)
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public void setNorm(int doc, String field, float value)
           throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     setNorm(doc, field, Similarity.encodeNorm(value));
   }
 
   /** Returns an enumeration of all the terms in the index.
    * The enumeration is ordered by Term.compareTo().  Each term
    * is greater than all that precede it in the enumeration.
+   * @throws IOException if there is a low-level IO error
    */
   public abstract TermEnum terms() throws IOException;
 
   /** Returns an enumeration of all terms after a given term.
    * The enumeration is ordered by Term.compareTo().  Each term
    * is greater than all that precede it in the enumeration.
+   * @throws IOException if there is a low-level IO error
    */
   public abstract TermEnum terms(Term t) throws IOException;
 
-  /** Returns the number of documents containing the term <code>t</code>. */
+  /** Returns the number of documents containing the term <code>t</code>.
+   * @throws IOException if there is a low-level IO error
+   */
   public abstract int docFreq(Term t) throws IOException;
 
   /** Returns an enumeration of all the documents which contain
@@ -536,14 +559,18 @@ public abstract class IndexReader {
    * </ul>
    * <p>The enumeration is ordered by document number.  Each document number
    * is greater than all that precede it in the enumeration.
+   * @throws IOException if there is a low-level IO error
    */
   public TermDocs termDocs(Term term) throws IOException {
+    ensureOpen();
     TermDocs termDocs = termDocs();
     termDocs.seek(term);
     return termDocs;
   }
 
-  /** Returns an unpositioned {@link TermDocs} enumerator. */
+  /** Returns an unpositioned {@link TermDocs} enumerator.
+   * @throws IOException if there is a low-level IO error
+   */
   public abstract TermDocs termDocs() throws IOException;
 
   /** Returns an enumeration of all the documents which contain
@@ -561,14 +588,18 @@ public abstract class IndexReader {
    * <p> This positional information faciliates phrase and proximity searching.
    * <p>The enumeration is ordered by document number.  Each document number is
    * greater than all that precede it in the enumeration.
+   * @throws IOException if there is a low-level IO error
    */
   public TermPositions termPositions(Term term) throws IOException {
+    ensureOpen();
     TermPositions termPositions = termPositions();
     termPositions.seek(term);
     return termPositions;
   }
 
-  /** Returns an unpositioned {@link TermPositions} enumerator. */
+  /** Returns an unpositioned {@link TermPositions} enumerator.
+   * @throws IOException if there is a low-level IO error
+   */
   public abstract TermPositions termPositions() throws IOException;
 
   /**
@@ -584,10 +615,9 @@ public abstract class IndexReader {
    * @throws IOException if there is a low-level IO error
    */
   private void acquireWriteLock() throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     if (stale)
       throw new StaleReaderException("IndexReader out of date and no longer valid for delete, undelete, or setNorm operations");
-    if (isClosed)
-      throw new IOException("this reader is closed");
 
     if (writeLock == null) {
       Lock writeLock = directory.makeLock(IndexWriter.WRITE_LOCK_NAME);
@@ -620,10 +650,10 @@ public abstract class IndexReader {
    * @throws LockObtainFailedException if another writer
    *  has this index open (<code>write.lock</code> could not
    *  be obtained)
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public final synchronized void deleteDocument(int docNum) throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     if(directoryOwner)
       acquireWriteLock();
     hasChanges = true;
@@ -652,10 +682,10 @@ public abstract class IndexReader {
    * @throws LockObtainFailedException if another writer
    *  has this index open (<code>write.lock</code> could not
    *  be obtained)
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public final int deleteDocuments(Term term) throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     TermDocs docs = termDocs(term);
     if (docs == null) return 0;
     int n = 0;
@@ -678,10 +708,10 @@ public abstract class IndexReader {
    *  has this index open (<code>write.lock</code> could not
    *  be obtained)
    * @throws CorruptIndexException if the index is corrupt
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public final synchronized void undeleteAll() throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
+    ensureOpen();
     if(directoryOwner)
       acquireWriteLock();
     hasChanges = true;
@@ -790,19 +820,16 @@ public abstract class IndexReader {
    * Closes files associated with this index.
    * Also saves any new deletions to disk.
    * No other methods should be called after this has been called.
-   * @throws IOException if this reader was closed already
+   * @throws IOException if there is a low-level IO error
-   *  or there is a low-level IO error
    */
   public final synchronized void close() throws IOException {
-    if (directoryOwner && isClosed) {
+    if (!closed) {
-      throw new IOException("this reader is already closed");
-    }
       commit();
       doClose();
+      if (directoryOwner)
+        closed = true;
       if(closeDirectory)
         directory.close();
-    if (directoryOwner) {
-      isClosed = true;
     }
   }
 

src/java/org/apache/lucene/index/IndexWriter.java

@@ -24,6 +24,7 @@ import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockObtainFailedException;
+import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.RAMDirectory;
 
 import java.io.File;
@@ -208,6 +209,16 @@ public class IndexWriter {
   private boolean useCompoundFile = true;
 
   private boolean closeDir;
+  private boolean closed;
+
+  /**
+   * @throws AlreadyClosedException if this IndexWriter is closed
+   */
+  protected final void ensureOpen() throws AlreadyClosedException {
+    if (closed) {
+      throw new AlreadyClosedException("this IndexWriter is closed");
+    }
+  }
 
   /** Get the current setting of whether to use the compound file format.
    *  Note that this just returns the value you set with setUseCompoundFile(boolean)
@@ -215,6 +226,7 @@ public class IndexWriter {
    *  @see #setUseCompoundFile(boolean)
    */
   public boolean getUseCompoundFile() {
+    ensureOpen();
     return useCompoundFile;
   }
 
@@ -223,6 +235,7 @@ public class IndexWriter {
    *  is finished. This is done regardless of what directory is in use.
    */
   public void setUseCompoundFile(boolean value) {
+    ensureOpen();
     useCompoundFile = value;
   }
 
@@ -231,6 +244,7 @@ public class IndexWriter {
    * @see Similarity#setDefault(Similarity)
    */
   public void setSimilarity(Similarity similarity) {
+    ensureOpen();
     this.similarity = similarity;
   }
 
@@ -239,6 +253,7 @@ public class IndexWriter {
    * <p>This defaults to the current value of {@link Similarity#getDefault()}.
    */
   public Similarity getSimilarity() {
+    ensureOpen();
     return this.similarity;
   }
 
@@ -264,6 +279,7 @@ public class IndexWriter {
    * @see #DEFAULT_TERM_INDEX_INTERVAL
    */
   public void setTermIndexInterval(int interval) {
+    ensureOpen();
     this.termIndexInterval = interval;
   }
 
@@ -271,7 +287,10 @@ public class IndexWriter {
    *
    * @see #setTermIndexInterval(int)
    */
-  public int getTermIndexInterval() { return termIndexInterval; }
+  public int getTermIndexInterval() {
+    ensureOpen();
+    return termIndexInterval;
+  }
 
   /**
    * Constructs an IndexWriter for the index in <code>path</code>.
@@ -580,6 +599,7 @@ public class IndexWriter {
    * <p>The default value is {@link Integer#MAX_VALUE}.
    */
   public void setMaxMergeDocs(int maxMergeDocs) {
+    ensureOpen();
     this.maxMergeDocs = maxMergeDocs;
   }
 
@@ -587,6 +607,7 @@ public class IndexWriter {
    * @see #setMaxMergeDocs
    */
   public int getMaxMergeDocs() {
+    ensureOpen();
     return maxMergeDocs;
   }
 
@@ -603,6 +624,7 @@ public class IndexWriter {
    * By default, no more than 10,000 terms will be indexed for a field.
    */
   public void setMaxFieldLength(int maxFieldLength) {
+    ensureOpen();
     this.maxFieldLength = maxFieldLength;
   }
 
@@ -610,6 +632,7 @@ public class IndexWriter {
    * @see #setMaxFieldLength
    */
   public int getMaxFieldLength() {
+    ensureOpen();
     return maxFieldLength;
   }
 
@@ -624,6 +647,7 @@ public class IndexWriter {
    * @throws IllegalArgumentException if maxBufferedDocs is smaller than 2
    */
   public void setMaxBufferedDocs(int maxBufferedDocs) {
+    ensureOpen();
     if (maxBufferedDocs < 2)
       throw new IllegalArgumentException("maxBufferedDocs must at least be 2");
     this.minMergeDocs = maxBufferedDocs;
@@ -633,6 +657,7 @@ public class IndexWriter {
    * @see #setMaxBufferedDocs
    */
   public int getMaxBufferedDocs() {
+    ensureOpen();
     return minMergeDocs;
   }
 
@@ -646,6 +671,7 @@ public class IndexWriter {
    * @throws IllegalArgumentException if maxBufferedDeleteTerms is smaller than 1</p>
    */
   public void setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms) {
+    ensureOpen();
     if (maxBufferedDeleteTerms < 1)
       throw new IllegalArgumentException("maxBufferedDeleteTerms must at least be 1");
     this.maxBufferedDeleteTerms = maxBufferedDeleteTerms;
@@ -655,6 +681,7 @@ public class IndexWriter {
    * @see #setMaxBufferedDeleteTerms
    */
   public int getMaxBufferedDeleteTerms() {
+    ensureOpen();
     return maxBufferedDeleteTerms;
   }
 
@@ -669,6 +696,7 @@ public class IndexWriter {
    * <p>This must never be less than 2.  The default value is 10.
    */
   public void setMergeFactor(int mergeFactor) {
+    ensureOpen();
     if (mergeFactor < 2)
       throw new IllegalArgumentException("mergeFactor cannot be less than 2");
     this.mergeFactor = mergeFactor;
@@ -678,6 +706,7 @@ public class IndexWriter {
    * @see #setMergeFactor
    */
   public int getMergeFactor() {
+    ensureOpen();
     return mergeFactor;
   }
 
@@ -701,6 +730,7 @@ public class IndexWriter {
    * to this.
    */
   public void setInfoStream(PrintStream infoStream) {
+    ensureOpen();
     this.infoStream = infoStream;
     deleter.setInfoStream(infoStream);
   }
@@ -709,6 +739,7 @@ public class IndexWriter {
    * @see #setInfoStream
    */
   public PrintStream getInfoStream() {
+    ensureOpen();
     return infoStream;
   }
 
@@ -717,6 +748,7 @@ public class IndexWriter {
    * @see #setDefaultWriteLockTimeout to change the default value for all instances of IndexWriter.
    */
   public void setWriteLockTimeout(long writeLockTimeout) {
+    ensureOpen();
     this.writeLockTimeout = writeLockTimeout;
   }
 
@@ -724,6 +756,7 @@ public class IndexWriter {
    * @see #setWriteLockTimeout
    */
   public long getWriteLockTimeout() {
+    ensureOpen();
     return writeLockTimeout;
   }
 
@@ -777,6 +810,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public synchronized void close() throws CorruptIndexException, IOException {
+    if (!closed) {
       flushRamSegments();
 
       if (commitPending) {
@@ -791,9 +825,12 @@ public class IndexWriter {
         writeLock.release();                          // release write lock
         writeLock = null;
       }
+      closed = true;
+
       if(closeDir)
         directory.close();
     }
+  }
 
   /** Release the write lock, if needed. */
   protected void finalize() throws Throwable {
@@ -809,17 +846,20 @@ public class IndexWriter {
 
   /** Returns the Directory used by this index. */
   public Directory getDirectory() {
+    ensureOpen();
     return directory;
   }
 
   /** Returns the analyzer used by this index. */
   public Analyzer getAnalyzer() {
+    ensureOpen();
     return analyzer;
   }
 
 
   /** Returns the number of documents currently in this index. */
   public synchronized int docCount() {
+    ensureOpen();
     int count = ramSegmentInfos.size();
     for (int i = 0; i < segmentInfos.size(); i++) {
       SegmentInfo si = segmentInfos.info(i);
@@ -897,6 +937,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public void addDocument(Document doc, Analyzer analyzer) throws CorruptIndexException, IOException {
+    ensureOpen();
     SegmentInfo newSegmentInfo = buildSingleDocSegment(doc, analyzer);
     synchronized (this) {
       ramSegmentInfos.addElement(newSegmentInfo);
@@ -922,6 +963,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public synchronized void deleteDocuments(Term term) throws CorruptIndexException, IOException {
+    ensureOpen();
     bufferDeleteTerm(term);
     maybeFlushRamSegments();
   }
@@ -935,6 +977,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public synchronized void deleteDocuments(Term[] terms) throws CorruptIndexException, IOException {
+    ensureOpen();
     for (int i = 0; i < terms.length; i++) {
       bufferDeleteTerm(terms[i]);
     }
@@ -954,6 +997,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public void updateDocument(Term term, Document doc) throws CorruptIndexException, IOException {
+    ensureOpen();
     updateDocument(term, doc, getAnalyzer());
   }
 
@@ -972,6 +1016,7 @@ public class IndexWriter {
    */
   public void updateDocument(Term term, Document doc, Analyzer analyzer)
       throws CorruptIndexException, IOException {
+    ensureOpen();
     SegmentInfo newSegmentInfo = buildSingleDocSegment(doc, analyzer);
     synchronized (this) {
       bufferDeleteTerm(term);
@@ -1107,6 +1152,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
   */
   public synchronized void optimize() throws CorruptIndexException, IOException {
+    ensureOpen();
     flushRamSegments();
     while (segmentInfos.size() > 1 ||
            (segmentInfos.size() == 1 &&
@@ -1200,6 +1246,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public void abort() throws IOException {
+    ensureOpen();
     if (!autoCommit) {
 
       // Keep the same segmentInfos instance but replace all
@@ -1290,6 +1337,7 @@ public class IndexWriter {
   public synchronized void addIndexes(Directory[] dirs)
     throws CorruptIndexException, IOException {
 
+    ensureOpen();
     optimize();					  // start with zero or 1 seg
 
     int start = segmentInfos.size();
@@ -1375,6 +1423,7 @@ public class IndexWriter {
 
     // 1 flush ram segments
 
+    ensureOpen();
     flushRamSegments();
 
     // 2 copy segment infos and find the highest level from dirs
@@ -1479,6 +1528,7 @@ public class IndexWriter {
   public synchronized void addIndexes(IndexReader[] readers)
     throws CorruptIndexException, IOException {
 
+    ensureOpen();
     optimize();					  // start with zero or 1 seg
 
     final String mergedName = newSegmentName();
@@ -1610,6 +1660,7 @@ public class IndexWriter {
    * @throws IOException if there is a low-level IO error
    */
   public final synchronized void flush() throws CorruptIndexException, IOException {
+    ensureOpen();
     flushRamSegments();
   }
 
@@ -1617,6 +1668,7 @@ public class IndexWriter {
    * Useful for size management with flushRamDocs()
    */
   public final long ramSizeInBytes() {
+    ensureOpen();
     return ramDirectory.sizeInBytes();
   }
 
@@ -1624,6 +1676,7 @@ public class IndexWriter {
    * Useful when calling flushRamSegments()
    */
   public final synchronized int numRamDocs() {
+    ensureOpen();
     return ramSegmentInfos.size();
   }
   

src/java/org/apache/lucene/index/MultiReader.java

@@ -72,24 +72,21 @@ public class MultiReader extends IndexReader {
   }
 
 
-  /** Return an array of term frequency vectors for the specified document.
-   *  The array contains a vector for each vectorized field in the document.
-   *  Each vector vector contains term numbers and frequencies for all terms
-   *  in a given vectorized field.
-   *  If no such fields existed, the method returns null.
-   */
   public TermFreqVector[] getTermFreqVectors(int n) throws IOException {
+    ensureOpen();
     int i = readerIndex(n);        // find segment num
     return subReaders[i].getTermFreqVectors(n - starts[i]); // dispatch to segment
   }
 
   public TermFreqVector getTermFreqVector(int n, String field)
       throws IOException {
+    ensureOpen();
     int i = readerIndex(n);        // find segment num
     return subReaders[i].getTermFreqVector(n - starts[i], field);
   }
 
   public synchronized int numDocs() {
+    // Don't call ensureOpen() here (it could affect performance)
     if (numDocs == -1) {        // check cache
       int n = 0;                // cache miss--recompute
       for (int i = 0; i < subReaders.length; i++)
@@ -100,21 +97,27 @@ public class MultiReader extends IndexReader {
   }
 
   public int maxDoc() {
+    // Don't call ensureOpen() here (it could affect performance)
     return maxDoc;
   }
 
   // inherit javadoc
   public Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
+    ensureOpen();
     int i = readerIndex(n);                          // find segment num
     return subReaders[i].document(n - starts[i], fieldSelector);    // dispatch to segment reader
   }
 
   public boolean isDeleted(int n) {
+    // Don't call ensureOpen() here (it could affect performance)
     int i = readerIndex(n);                           // find segment num
     return subReaders[i].isDeleted(n - starts[i]);    // dispatch to segment reader
   }
 
-  public boolean hasDeletions() { return hasDeletions; }
+  public boolean hasDeletions() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return hasDeletions;
+  }
 
   protected void doDelete(int n) throws CorruptIndexException, IOException {
     numDocs = -1;                             // invalidate cache
@@ -153,6 +156,7 @@ public class MultiReader extends IndexReader {
   }
 
   public boolean hasNorms(String field) throws IOException {
+    ensureOpen();
     for (int i = 0; i < subReaders.length; i++) {
       if (subReaders[i].hasNorms(field)) return true;
     }
@@ -166,6 +170,7 @@ public class MultiReader extends IndexReader {
   }
 
   public synchronized byte[] norms(String field) throws IOException {
+    ensureOpen();
     byte[] bytes = (byte[])normsCache.get(field);
     if (bytes != null)
       return bytes;          // cache hit
@@ -181,6 +186,7 @@ public class MultiReader extends IndexReader {
 
   public synchronized void norms(String field, byte[] result, int offset)
     throws IOException {
+    ensureOpen();
     byte[] bytes = (byte[])normsCache.get(field);
     if (bytes==null && !hasNorms(field)) bytes=fakeNorms();
     if (bytes != null)                            // cache hit
@@ -198,14 +204,17 @@ public class MultiReader extends IndexReader {
   }
 
   public TermEnum terms() throws IOException {
+    ensureOpen();
     return new MultiTermEnum(subReaders, starts, null);
   }
 
   public TermEnum terms(Term term) throws IOException {
+    ensureOpen();
     return new MultiTermEnum(subReaders, starts, term);
   }
 
   public int docFreq(Term t) throws IOException {
+    ensureOpen();
     int total = 0;          // sum freqs in segments
     for (int i = 0; i < subReaders.length; i++)
       total += subReaders[i].docFreq(t);
@@ -213,10 +222,12 @@ public class MultiReader extends IndexReader {
   }
 
   public TermDocs termDocs() throws IOException {
+    ensureOpen();
     return new MultiTermDocs(subReaders, starts);
   }
 
   public TermPositions termPositions() throws IOException {
+    ensureOpen();
     return new MultiTermPositions(subReaders, starts);
   }
 
@@ -244,11 +255,9 @@ public class MultiReader extends IndexReader {
       subReaders[i].close();
   }
 
-  /**
-   * @see IndexReader#getFieldNames(IndexReader.FieldOption)
-   */
   public Collection getFieldNames (IndexReader.FieldOption fieldNames) {
     // maintain a unique set of field names
+    ensureOpen();
     Set fieldSet = new HashSet();
     for (int i = 0; i < subReaders.length; i++) {
       IndexReader reader = subReaders[i];

src/java/org/apache/lucene/index/ParallelReader.java

@@ -66,8 +66,11 @@ public class ParallelReader extends IndexReader {
  /** Construct a ParallelReader. */
   public ParallelReader() throws IOException { super(null); }
 
- /** Add an IndexReader. */
+ /** Add an IndexReader.
+  * @throws IOException if there is a low-level IO error
+  */
   public void add(IndexReader reader) throws IOException {
+    ensureOpen();
     add(reader, false);
   }
 
@@ -79,10 +82,12 @@ public class ParallelReader extends IndexReader {
   *     of documents
   * @throws IllegalArgumentException if not all indexes have the same value
   *     of {@link IndexReader#maxDoc()}
+  * @throws IOException if there is a low-level IO error
   */
   public void add(IndexReader reader, boolean ignoreStoredFields)
     throws IOException {
 
+    ensureOpen();
     if (readers.size() == 0) {
       this.maxDoc = reader.maxDoc();
       this.numDocs = reader.numDocs();
@@ -110,14 +115,24 @@ public class ParallelReader extends IndexReader {
     readers.add(reader);
   }
 
-  public int numDocs() { return numDocs; }
+  public int numDocs() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return numDocs;
+  }
 
-  public int maxDoc() { return maxDoc; }
+  public int maxDoc() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return maxDoc;
+  }
 
-  public boolean hasDeletions() { return hasDeletions; }
+  public boolean hasDeletions() {
+    // Don't call ensureOpen() here (it could affect performance)
+    return hasDeletions;
+  }
 
   // check first reader
   public boolean isDeleted(int n) {
+    // Don't call ensureOpen() here (it could affect performance)
     if (readers.size() > 0)
       return ((IndexReader)readers.get(0)).isDeleted(n);
     return false;
@@ -141,6 +156,7 @@ public class ParallelReader extends IndexReader {
 
   // append fields from storedFieldReaders
   public Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
+    ensureOpen();
     Document result = new Document();
     for (int i = 0; i < storedFieldReaders.size(); i++) {
       IndexReader reader = (IndexReader)storedFieldReaders.get(i);
@@ -166,6 +182,7 @@ public class ParallelReader extends IndexReader {
 
   // get all vectors
   public TermFreqVector[] getTermFreqVectors(int n) throws IOException {
+    ensureOpen();
     ArrayList results = new ArrayList();
     Iterator i = fieldToReader.entrySet().iterator();
     while (i.hasNext()) {
@@ -182,22 +199,26 @@ public class ParallelReader extends IndexReader {
 
   public TermFreqVector getTermFreqVector(int n, String field)
     throws IOException {
+    ensureOpen();
     IndexReader reader = ((IndexReader)fieldToReader.get(field));
     return reader==null ? null : reader.getTermFreqVector(n, field);
   }
 
   public boolean hasNorms(String field) throws IOException {
+    ensureOpen();
     IndexReader reader = ((IndexReader)fieldToReader.get(field));
     return reader==null ? false : reader.hasNorms(field);
   }
 
   public byte[] norms(String field) throws IOException {
+    ensureOpen();
     IndexReader reader = ((IndexReader)fieldToReader.get(field));
     return reader==null ? null : reader.norms(field);
   }
 
   public void norms(String field, byte[] result, int offset)
     throws IOException {
+    ensureOpen();
     IndexReader reader = ((IndexReader)fieldToReader.get(field));
     if (reader!=null)
       reader.norms(field, result, offset);
@@ -211,31 +232,38 @@ public class ParallelReader extends IndexReader {
   }
 
   public TermEnum terms() throws IOException {
+    ensureOpen();
     return new ParallelTermEnum();
   }
 
   public TermEnum terms(Term term) throws IOException {
+    ensureOpen();
     return new ParallelTermEnum(term);
   }
 
   public int docFreq(Term term) throws IOException {
+    ensureOpen();
     IndexReader reader = ((IndexReader)fieldToReader.get(term.field()));
     return reader==null ? 0 : reader.docFreq(term);
   }
 
   public TermDocs termDocs(Term term) throws IOException {
+    ensureOpen();
     return new ParallelTermDocs(term);
   }
 
   public TermDocs termDocs() throws IOException {
+    ensureOpen();
     return new ParallelTermDocs();
   }
 
   public TermPositions termPositions(Term term) throws IOException {
+    ensureOpen();
     return new ParallelTermPositions(term);
   }
 
   public TermPositions termPositions() throws IOException {
+    ensureOpen();
     return new ParallelTermPositions();
   }
 
@@ -251,6 +279,7 @@ public class ParallelReader extends IndexReader {
 
 
   public Collection getFieldNames (IndexReader.FieldOption fieldNames) {
+    ensureOpen();
     Set fieldSet = new HashSet();
     for (int i = 0; i < readers.size(); i++) {
       IndexReader reader = ((IndexReader)readers.get(i));

src/java/org/apache/lucene/index/SegmentReader.java

@@ -266,10 +266,12 @@ class SegmentReader extends IndexReader {
   }
 
   static boolean hasDeletions(SegmentInfo si) throws IOException {
+    // Don't call ensureOpen() here (it could affect performance)
     return si.hasDeletions();
   }
 
   public boolean hasDeletions() {
+    // Don't call ensureOpen() here (it could affect performance)
     return deletedDocs != null;
   }
 
@@ -300,10 +302,12 @@ class SegmentReader extends IndexReader {
   }
 
   public TermEnum terms() {
+    ensureOpen();
     return tis.terms();
   }
 
   public TermEnum terms(Term t) throws IOException {
+    ensureOpen();
     return tis.terms(t);
   }
 
@@ -312,6 +316,7 @@ class SegmentReader extends IndexReader {
    * @throws IOException if there is a low-level IO error
    */
   public synchronized Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
+    ensureOpen();
     if (isDeleted(n))
       throw new IllegalArgumentException
               ("attempt to access a deleted document");
@@ -323,14 +328,17 @@ class SegmentReader extends IndexReader {
   }
 
   public TermDocs termDocs() throws IOException {
+    ensureOpen();
     return new SegmentTermDocs(this);
   }
 
   public TermPositions termPositions() throws IOException {
+    ensureOpen();
     return new SegmentTermPositions(this);
   }
 
   public int docFreq(Term t) throws IOException {
+    ensureOpen();
     TermInfo ti = tis.get(t);
     if (ti != null)
       return ti.docFreq;
@@ -339,6 +347,7 @@ class SegmentReader extends IndexReader {
   }
 
   public int numDocs() {
+    // Don't call ensureOpen() here (it could affect performance)
     int n = maxDoc();
     if (deletedDocs != null)
       n -= deletedDocs.count();
@@ -346,6 +355,7 @@ class SegmentReader extends IndexReader {
   }
 
   public int maxDoc() {
+    // Don't call ensureOpen() here (it could affect performance)
     return si.docCount;
   }
 
@@ -353,6 +363,7 @@ class SegmentReader extends IndexReader {
    * @see IndexReader#getFieldNames(IndexReader.FieldOption fldOption)
    */
   public Collection getFieldNames(IndexReader.FieldOption fieldOption) {
+    ensureOpen();
 
     Set fieldSet = new HashSet();
     for (int i = 0; i < fieldInfos.size(); i++) {
@@ -394,6 +405,7 @@ class SegmentReader extends IndexReader {
 
 
   public synchronized boolean hasNorms(String field) {
+    ensureOpen();
     return norms.containsKey(field);
   }
 
@@ -426,6 +438,7 @@ class SegmentReader extends IndexReader {
 
   // returns fake norms if norms aren't available
   public synchronized byte[] norms(String field) throws IOException {
+    ensureOpen();
     byte[] bytes = getNorms(field);
     if (bytes==null) bytes=fakeNorms();
     return bytes;
@@ -447,6 +460,7 @@ class SegmentReader extends IndexReader {
   public synchronized void norms(String field, byte[] bytes, int offset)
     throws IOException {
 
+    ensureOpen();
     Norm norm = (Norm) norms.get(field);
     if (norm == null) {
       System.arraycopy(fakeNorms(), 0, bytes, offset, maxDoc());
@@ -537,6 +551,7 @@ class SegmentReader extends IndexReader {
    */
   public TermFreqVector getTermFreqVector(int docNumber, String field) throws IOException {
     // Check if this field is invalid or has no stored term vector
+    ensureOpen();
     FieldInfo fi = fieldInfos.fieldInfo(field);
     if (fi == null || !fi.storeTermVector || termVectorsReaderOrig == null) 
       return null;
@@ -557,6 +572,7 @@ class SegmentReader extends IndexReader {
    * @throws IOException
    */
   public TermFreqVector[] getTermFreqVectors(int docNumber) throws IOException {
+    ensureOpen();
     if (termVectorsReaderOrig == null)
       return null;
     

src/java/org/apache/lucene/store/AlreadyClosedException.java

@@ -0,0 +1,28 @@
+package org.apache.lucene.store;
+
+/**
+ * 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.
+ */
+
+/**
+ * This exception is thrown when there is an attempt to
+ * access something that has already been closed.
+ */
+public class AlreadyClosedException extends IllegalStateException {
+  public AlreadyClosedException(String message) {
+    super(message);
+  }
+}

src/java/org/apache/lucene/store/RAMDirectory.java

@@ -97,6 +97,7 @@ public class RAMDirectory extends Directory implements Serializable {
 
   /** Returns an array of strings, one for each file in the directory. */
   public synchronized final String[] list() {
+    ensureOpen();
     Set fileNames = fileMap.keySet();
     String[] result = new String[fileNames.size()];
     int i = 0;
@@ -108,6 +109,7 @@ public class RAMDirectory extends Directory implements Serializable {
 
   /** Returns true iff the named file exists in this directory. */
   public final boolean fileExists(String name) {
+    ensureOpen();
     RAMFile file;
     synchronized (this) {
       file = (RAMFile)fileMap.get(name);
@@ -119,6 +121,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * @throws IOException if the file does not exist
    */
   public final long fileModified(String name) throws IOException {
+    ensureOpen();
     RAMFile file;
     synchronized (this) {
       file = (RAMFile)fileMap.get(name);
@@ -132,6 +135,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * @throws IOException if the file does not exist
    */
   public void touchFile(String name) throws IOException {
+    ensureOpen();
     RAMFile file;
     synchronized (this) {
       file = (RAMFile)fileMap.get(name);
@@ -154,6 +158,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * @throws IOException if the file does not exist
    */
   public final long fileLength(String name) throws IOException {
+    ensureOpen();
     RAMFile file;
     synchronized (this) {
       file = (RAMFile)fileMap.get(name);
@@ -167,6 +172,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * directory.  This is currently quantized to
    * BufferedIndexOutput.BUFFER_SIZE. */
   public synchronized final long sizeInBytes() {
+    ensureOpen();
     return sizeInBytes;
   }
   
@@ -174,6 +180,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * @throws IOException if the file does not exist
    */
   public synchronized void deleteFile(String name) throws IOException {
+    ensureOpen();
     RAMFile file = (RAMFile)fileMap.get(name);
     if (file!=null) {
         fileMap.remove(name);
@@ -188,6 +195,7 @@ public class RAMDirectory extends Directory implements Serializable {
    * @deprecated
    */
   public synchronized final void renameFile(String from, String to) throws IOException {
+    ensureOpen();
     RAMFile fromFile = (RAMFile)fileMap.get(from);
     if (fromFile==null)
       throw new FileNotFoundException(from);
@@ -202,6 +210,7 @@ public class RAMDirectory extends Directory implements Serializable {
 
   /** Creates a new, empty file in the directory with the given name. Returns a stream writing this file. */
   public IndexOutput createOutput(String name) {
+    ensureOpen();
     RAMFile file = new RAMFile(this);
     synchronized (this) {
       RAMFile existing = (RAMFile)fileMap.get(name);
@@ -216,6 +225,7 @@ public class RAMDirectory extends Directory implements Serializable {
 
   /** Returns a stream reading an existing file. */
   public IndexInput openInput(String name) throws IOException {
+    ensureOpen();
     RAMFile file;
     synchronized (this) {
       file = (RAMFile)fileMap.get(name);
@@ -230,4 +240,12 @@ public class RAMDirectory extends Directory implements Serializable {
     fileMap = null;
   }
 
+  /**
+   * @throws AlreadyClosedException if this IndexReader is closed
+   */
+  protected final void ensureOpen() throws AlreadyClosedException {
+    if (fileMap == null) {
+      throw new AlreadyClosedException("this RAMDirectory is closed");
+    }
+  }
 }

src/test/org/apache/lucene/index/TestFieldsReader.java

@@ -23,6 +23,7 @@ import org.apache.lucene.document.*;
 import org.apache.lucene.search.Similarity;
 import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.util._TestUtil;
 
 import java.io.File;
@@ -133,6 +134,36 @@ public class TestFieldsReader extends TestCase {
     }
   }
 
+  public void testLazyFieldsAfterClose() throws Exception {
+    assertTrue(dir != null);
+    assertTrue(fieldInfos != null);
+    FieldsReader reader = new FieldsReader(dir, "test", fieldInfos);
+    assertTrue(reader != null);
+    assertTrue(reader.size() == 1);
+    Set loadFieldNames = new HashSet();
+    loadFieldNames.add(DocHelper.TEXT_FIELD_1_KEY);
+    loadFieldNames.add(DocHelper.TEXT_FIELD_UTF1_KEY);
+    Set lazyFieldNames = new HashSet();
+    lazyFieldNames.add(DocHelper.LARGE_LAZY_FIELD_KEY);
+    lazyFieldNames.add(DocHelper.LAZY_FIELD_KEY);
+    lazyFieldNames.add(DocHelper.LAZY_FIELD_BINARY_KEY);
+    lazyFieldNames.add(DocHelper.TEXT_FIELD_UTF2_KEY);
+    lazyFieldNames.add(DocHelper.COMPRESSED_TEXT_FIELD_2_KEY);
+    SetBasedFieldSelector fieldSelector = new SetBasedFieldSelector(loadFieldNames, lazyFieldNames);
+    Document doc = reader.doc(0, fieldSelector);
+    assertTrue("doc is null and it shouldn't be", doc != null);
+    Fieldable field = doc.getFieldable(DocHelper.LAZY_FIELD_KEY);
+    assertTrue("field is null and it shouldn't be", field != null);
+    assertTrue("field is not lazy and it should be", field.isLazy());
+    reader.close();
+    try {
+      String value = field.stringValue();
+      fail("did not hit AlreadyClosedException as expected");
+    } catch (AlreadyClosedException e) {
+      // expected
+    }
+  }
+
   public void testLoadFirst() throws Exception {
     assertTrue(dir != null);
     assertTrue(fieldInfos != null);

src/test/org/apache/lucene/index/TestIndexReader.java

@@ -26,6 +26,7 @@ import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.LockObtainFailedException;
+import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.analysis.standard.StandardAnalyzer;
 import org.apache.lucene.analysis.WhitespaceAnalyzer;
 import org.apache.lucene.document.Document;
@@ -279,21 +280,21 @@ public class TestIndexReader extends TestCase
         try {
           reader.deleteDocument(4);
           fail("deleteDocument after close failed to throw IOException");
-        } catch (IOException e) {
+        } catch (AlreadyClosedException e) {
           // expected
         }
 
         try {
           reader.setNorm(5, "aaa", 2.0f);
           fail("setNorm after close failed to throw IOException");
-        } catch (IOException e) {
+        } catch (AlreadyClosedException e) {
           // expected
         }
 
         try {
           reader.undeleteAll();
           fail("undeleteAll after close failed to throw IOException");
-        } catch (IOException e) {
+        } catch (AlreadyClosedException e) {
           // expected
         }
     }

src/test/org/apache/lucene/index/TestIndexWriter.java

@@ -19,6 +19,7 @@ import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.AlreadyClosedException;
 
 import org.apache.lucene.store.MockRAMDirectory;
 import org.apache.lucene.store.LockFactory;
@@ -724,6 +725,25 @@ public class TestIndexWriter extends TestCase
         }
     }
 
+    public void testChangesAfterClose() throws IOException {
+        Directory dir = new RAMDirectory();
+
+        IndexWriter writer = null;
+
+        writer  = new IndexWriter(dir, new WhitespaceAnalyzer(), true);
+        addDoc(writer);
+
+        // close
+        writer.close();
+        try {
+          addDoc(writer);
+          fail("did not hit AlreadyClosedException");
+        } catch (AlreadyClosedException e) {
+          // expected
+        }
+    }
+  
+
     // Simulate a corrupt index by removing one of the cfs
     // files and make sure we get an IOException trying to
     // open the index: