LUCENE-2608: Add per-method and request accuracy to spell checker

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@987179 13f79535-47bb-0310-9956-ffa450edef68

lucene/contrib/CHANGES.txt

@@ -23,6 +23,9 @@ New Features
   * LUCENE-2479: Added ability to provide a sort comparator for spelling suggestions along
     with two implementations.  The existing comparator (score, then frequency) is the default (Grant Ingersoll)
 
+  * LUCENE-2608: Added the ability to specify the accuracy at method time in the SpellChecker.  The per class
+    method is also still available.  (Grant Ingersoll)
+
 API Changes
 
   * LUCENE-2606: Changed RegexCapabilities interface to fix thread 

lucene/contrib/spellchecker/src/java/org/apache/lucene/search/spell/SpellChecker.java

@@ -62,11 +62,16 @@ import org.apache.lucene.util.Version;
  */
 public class SpellChecker implements java.io.Closeable {
 
+  /**
+   * The default minimum score to use, if not specified by calling {@link #setAccuracy(float)} .
+   */
+  public static final float DEFAULT_ACCURACY = 0.5f;
+
   /**
    * Field name for each word in the ngram index.
    */
   public static final String F_WORD = "word";
-  
+
   private static final Term F_WORD_TERM = new Term(F_WORD);
 
   /**
@@ -75,35 +80,34 @@ public class SpellChecker implements java.io.Closeable {
   // don't modify the directory directly - see #swapSearcher()
   // TODO: why is this package private?
   Directory spellIndex;
-
   /**
    * Boost value for start and end grams
    */
   private float bStart = 2.0f;
-  private float bEnd = 1.0f;
 
+  private float bEnd = 1.0f;
   // don't use this searcher directly - see #swapSearcher()
+
   private IndexSearcher searcher;
-  
   /*
-   * this locks all modifications to the current searcher. 
+   * this locks all modifications to the current searcher.
    */
+
   private final Object searcherLock = new Object();
-  
   /*
-   * this lock synchronizes all possible modifications to the 
+   * this lock synchronizes all possible modifications to the
    * current index directory. It should not be possible to try modifying
    * the same index concurrently. Note: Do not acquire the searcher lock
-   * before acquiring this lock! 
+   * before acquiring this lock!
    */
   private final Object modifyCurrentIndexLock = new Object();
+
   private volatile boolean closed = false;
-
   // minimum score for hits generated by the spell checker query
-  private float minScore = 0.5f;
-  
-  private StringDistance sd;
 
+  private float accuracy = DEFAULT_ACCURACY;
+
+  private StringDistance sd;
   private Comparator<SuggestWord> comparator;
 
   /**
@@ -202,10 +206,20 @@ public class SpellChecker implements java.io.Closeable {
   }
 
   /**
-   * Sets the accuracy 0 &lt; minScore &lt; 1; default 0.5
+   * Sets the accuracy 0 &lt; minScore &lt; 1; default {@link #DEFAULT_ACCURACY}
+   * @param acc The new accuracy
    */
-  public void setAccuracy(float minScore) {
+  public void setAccuracy(float acc) {
-    this.minScore = minScore;
+    this.accuracy = acc;
+  }
+
+  /**
+   * The accuracy (minimum score) to be used, unless overridden in {@link #suggestSimilar(String, int, org.apache.lucene.index.IndexReader, String, boolean, float)}, to
+   * decide whether a suggestion is included or not.
+   * @return The current accuracy setting
+   */
+  public float getAccuracy() {
+    return accuracy;
   }
 
   /**
@@ -224,11 +238,37 @@ public class SpellChecker implements java.io.Closeable {
    * @throws IOException if the underlying index throws an {@link IOException}
    * @throws AlreadyClosedException if the Spellchecker is already closed
    * @return String[]
+   *
+   * @see #suggestSimilar(String, int, org.apache.lucene.index.IndexReader, String, boolean, float) 
    */
   public String[] suggestSimilar(String word, int numSug) throws IOException {
     return this.suggestSimilar(word, numSug, null, null, false);
   }
 
+  /**
+   * Suggest similar words.
+   *
+   * <p>As the Lucene similarity that is used to fetch the most relevant n-grammed terms
+   * is not the same as the edit distance strategy used to calculate the best
+   * matching spell-checked word from the hits that Lucene found, one usually has
+   * to retrieve a couple of numSug's in order to get the true best match.
+   *
+   * <p>I.e. if numSug == 1, don't count on that suggestion being the best one.
+   * Thus, you should set this value to <b>at least</b> 5 for a good suggestion.
+   *
+   * @param word the word you want a spell check done on
+   * @param numSug the number of suggested words
+   * @param accuracy The minimum score a suggestion must have in order to qualify for inclusion in the results
+   * @throws IOException if the underlying index throws an {@link IOException}
+   * @throws AlreadyClosedException if the Spellchecker is already closed
+   * @return String[]
+   *
+   * @see #suggestSimilar(String, int, org.apache.lucene.index.IndexReader, String, boolean, float)
+   */
+  public String[] suggestSimilar(String word, int numSug, float accuracy) throws IOException {
+    return this.suggestSimilar(word, numSug, null, null, false, accuracy);
+  }
+
   /**
    * Suggest similar words (optionally restricted to a field of an index).
    * 
@@ -240,6 +280,40 @@ public class SpellChecker implements java.io.Closeable {
    * <p>I.e. if numSug == 1, don't count on that suggestion being the best one.
    * Thus, you should set this value to <b>at least</b> 5 for a good suggestion.
    *
+   * <p>Uses the {@link #getAccuracy()} value passed into the constructor as the accuracy.
+   *
+   * @param word the word you want a spell check done on
+   * @param numSug the number of suggested words
+   * @param ir the indexReader of the user index (can be null see field param)
+   * @param field the field of the user index: if field is not null, the suggested
+   * words are restricted to the words present in this field.
+   * @param morePopular return only the suggest words that are as frequent or more frequent than the searched word
+   * (only if restricted mode = (indexReader!=null and field!=null)
+   * @throws IOException if the underlying index throws an {@link IOException}
+   * @throws AlreadyClosedException if the Spellchecker is already closed
+   * @return String[] the sorted list of the suggest words with these 2 criteria:
+   * first criteria: the edit distance, second criteria (only if restricted mode): the popularity
+   * of the suggest words in the field of the user index
+   *
+   * @see #suggestSimilar(String, int, org.apache.lucene.index.IndexReader, String, boolean, float)
+   */
+  public String[] suggestSimilar(String word, int numSug, IndexReader ir,
+      String field, boolean morePopular) throws IOException {
+    return suggestSimilar(word, numSug, ir, field, morePopular, accuracy);
+  }
+
+
+  /**
+   * Suggest similar words (optionally restricted to a field of an index).
+   *
+   * <p>As the Lucene similarity that is used to fetch the most relevant n-grammed terms
+   * is not the same as the edit distance strategy used to calculate the best
+   * matching spell-checked word from the hits that Lucene found, one usually has
+   * to retrieve a couple of numSug's in order to get the true best match.
+   *
+   * <p>I.e. if numSug == 1, don't count on that suggestion being the best one.
+   * Thus, you should set this value to <b>at least</b> 5 for a good suggestion.
+   *
    * @param word the word you want a spell check done on
    * @param numSug the number of suggested words
    * @param ir the indexReader of the user index (can be null see field param)
@@ -247,6 +321,7 @@ public class SpellChecker implements java.io.Closeable {
    * words are restricted to the words present in this field.
    * @param morePopular return only the suggest words that are as frequent or more frequent than the searched word
    * (only if restricted mode = (indexReader!=null and field!=null)
+   * @param accuracy The minimum score a suggestion must have in order to qualify for inclusion in the results
    * @throws IOException if the underlying index throws an {@link IOException}
    * @throws AlreadyClosedException if the Spellchecker is already closed
    * @return String[] the sorted list of the suggest words with these 2 criteria:
@@ -254,72 +329,72 @@ public class SpellChecker implements java.io.Closeable {
    * of the suggest words in the field of the user index
    */
   public String[] suggestSimilar(String word, int numSug, IndexReader ir,
-      String field, boolean morePopular) throws IOException {
+      String field, boolean morePopular, float accuracy) throws IOException {
     // obtainSearcher calls ensureOpen
     final IndexSearcher indexSearcher = obtainSearcher();
     try{
-      float min = this.minScore;
+
       final int lengthWord = word.length();
-  
+
       final int freq = (ir != null && field != null) ? ir.docFreq(new Term(field, word)) : 0;
       final int goalFreq = (morePopular && ir != null && field != null) ? freq : 0;
       // if the word exists in the real index and we don't care for word frequency, return the word itself
       if (!morePopular && freq > 0) {
         return new String[] { word };
       }
-  
+
       BooleanQuery query = new BooleanQuery();
       String[] grams;
       String key;
-  
+
       for (int ng = getMin(lengthWord); ng <= getMax(lengthWord); ng++) {
-  
+
         key = "gram" + ng; // form key
-  
+
         grams = formGrams(word, ng); // form word into ngrams (allow dups too)
-  
+
         if (grams.length == 0) {
           continue; // hmm
         }
-  
+
         if (bStart > 0) { // should we boost prefixes?
           add(query, "start" + ng, grams[0], bStart); // matches start of word
-  
+
         }
         if (bEnd > 0) { // should we boost suffixes
           add(query, "end" + ng, grams[grams.length - 1], bEnd); // matches end of word
-  
+
         }
         for (int i = 0; i < grams.length; i++) {
           add(query, key, grams[i]);
         }
       }
-  
+
       int maxHits = 10 * numSug;
-      
+
   //    System.out.println("Q: " + query);
       ScoreDoc[] hits = indexSearcher.search(query, null, maxHits).scoreDocs;
   //    System.out.println("HITS: " + hits.length());
       SuggestWordQueue sugQueue = new SuggestWordQueue(numSug, comparator);
-  
+
       // go thru more than 'maxr' matches in case the distance filter triggers
       int stop = Math.min(hits.length, maxHits);
       SuggestWord sugWord = new SuggestWord();
       for (int i = 0; i < stop; i++) {
-  
+
         sugWord.string = indexSearcher.doc(hits[i].doc).get(F_WORD); // get orig word
-  
+
         // don't suggest a word for itself, that would be silly
         if (sugWord.string.equals(word)) {
           continue;
         }
-  
+
         // edit distance
         sugWord.score = sd.getDistance(word,sugWord.string);
-        if (sugWord.score < min) {
+        if (sugWord.score < accuracy) {
           continue;
         }
-  
+
         if (ir != null && field != null) { // use the user index
           sugWord.freq = ir.docFreq(new Term(field, sugWord.string)); // freq in the index
           // don't suggest a word that is not present in the field
@@ -330,23 +405,22 @@ public class SpellChecker implements java.io.Closeable {
         sugQueue.insertWithOverflow(sugWord);
         if (sugQueue.size() == numSug) {
           // if queue full, maintain the minScore score
-          min = sugQueue.top().score;
+          accuracy = sugQueue.top().score;
         }
         sugWord = new SuggestWord();
       }
-  
+
       // convert to array string
       String[] list = new String[sugQueue.size()];
       for (int i = sugQueue.size() - 1; i >= 0; i--) {
         list[i] = sugQueue.pop().string;
       }
-  
+
       return list;
     } finally {
       releaseSearcher(indexSearcher);
     }
   }
-
   /**
    * Add a clause to a boolean query.
    */

lucene/contrib/spellchecker/src/test/org/apache/lucene/search/spell/TestSpellChecker.java

@@ -104,11 +104,21 @@ public class TestSpellChecker extends LuceneTestCase {
     spellChecker.setAccuracy(0.8f);
     checkCommonSuggestions(r);
     checkJaroWinklerSuggestions();
+    // the accuracy is set to 0.8 by default, but the best result has a score of 0.925
+    String[] similar = spellChecker.suggestSimilar("fvie", 2, 0.93f);
+    assertTrue(similar.length == 0);
+    similar = spellChecker.suggestSimilar("fvie", 2, 0.92f);
+    assertTrue(similar.length == 1);
+
+    similar = spellChecker.suggestSimilar("fiv", 2);
+    assertTrue(similar.length > 0);
+    assertEquals(similar[0], "five");
     
     spellChecker.setStringDistance(new NGramDistance(2));
     spellChecker.setAccuracy(0.5f);
     checkCommonSuggestions(r);
     checkNGramSuggestions();
+
     r.close();
   }
 
@@ -127,8 +137,6 @@ public class TestSpellChecker extends LuceneTestCase {
     if (!compareSP.isClosed())
       compareSP.close();
     compIdx.close();
-
-
   }
 
   private void checkCommonSuggestions(IndexReader r) throws IOException {

solr/CHANGES.txt

@@ -77,6 +77,12 @@ Upgrading from Solr 1.4
   legacy behavior should set a default value for the 'mm' param in
   their solrconfig.xml file.
 
+* LUCENE-2608: Added the ability to specify the accuracy on a per request basis. 
+  Implementations of SolrSpellChecker must change over to the new SolrSpellChecker
+  abstract methods using the new SpellingOptions class.  While this change is not
+  backward compatible, it should be trivial to migrate as the SpellingOptions class
+  just encapsulates the parameters that were passed in to the methods before the change. (gsingers)
+
 Detailed Change List
 ----------------------
 
@@ -226,11 +232,6 @@ New Features
 
 * SOLR-2053: Add support for custom comparators in Solr spellchecker, per LUCENE-2479 (gsingers)
 
-* SOLR-2049: Add hl.multiValuedSeparatorChar for FastVectorHighlighter, per LUCENE-2603. (koji)
-
-* SOLR-1881: add a url-scheme config string to SearchHandler to specify alternate
-  URL prefixes for distributed search shard requests.  (Sami Siren via yonik)
-
 Optimizations
 ----------------------
 

solr/src/common/org/apache/solr/common/params/SpellingParams.java

@@ -81,4 +81,9 @@ public interface SpellingParams {
    * Take the top suggestion for each token and create a new query from it
    */
   public static final String SPELLCHECK_COLLATE = SPELLCHECK_PREFIX + "collate";
+
+  /**
+   * Certain spelling implementations may allow for an accuracy setting.
+   */
+  public static final String SPELLCHECK_ACCURACY = SPELLCHECK_PREFIX + "accuracy";
 }

solr/src/java/org/apache/solr/handler/component/SpellCheckComponent.java

@@ -23,11 +23,13 @@ import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.lucene.search.spell.LevensteinDistance;
+import org.apache.lucene.search.spell.SpellChecker;
 import org.apache.lucene.search.spell.StringDistance;
 import org.apache.lucene.search.spell.SuggestWord;
 import org.apache.lucene.search.spell.SuggestWordQueue;
 import org.apache.lucene.util.PriorityQueue;
 import org.apache.solr.client.solrj.response.SpellCheckResponse;
+import org.apache.solr.common.params.ModifiableSolrParams;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -144,8 +146,12 @@ public class SpellCheckComponent extends SearchComponent implements SolrCoreAwar
         NamedList response = new SimpleOrderedMap();
         IndexReader reader = rb.req.getSearcher().getReader();
         boolean collate = params.getBool(SPELLCHECK_COLLATE, false);
-        SpellingResult spellingResult = spellChecker.getSuggestions(tokens,
+        float accuracy = params.getFloat(SPELLCHECK_ACCURACY, Float.MIN_VALUE);
-            reader, count, onlyMorePopular, extendedResults);
+        SolrParams customParams = getCustomParams(getDictionaryName(params), params);
+        SpellingOptions options = new SpellingOptions(tokens, reader, count, onlyMorePopular, extendedResults,
+                accuracy, customParams);
+
+        SpellingResult spellingResult = spellChecker.getSuggestions(options);
         if (spellingResult != null) {
           response.add("suggestions", toNamedList(spellingResult, q,
               extendedResults, collate));
@@ -159,6 +165,24 @@ public class SpellCheckComponent extends SearchComponent implements SolrCoreAwar
     }
   }
 
+  /**
+   * For every param that is of the form "spellcheck.[dictionary name].XXXX=YYYY, add
+   * XXXX=YYYY as a param to the custom param list
+   * @param params The original SolrParams
+   * @return The new Params
+   */
+  protected SolrParams getCustomParams(String dictionary, SolrParams params) {
+    ModifiableSolrParams result = new ModifiableSolrParams();
+    Iterator<String> iter = params.getParameterNamesIterator();
+    String prefix = SpellingParams.SPELLCHECK_PREFIX + "." + dictionary + ".";
+    while (iter.hasNext()){
+      String nxt = iter.next();
+      if (nxt.startsWith(prefix)){
+        result.add(nxt.substring(prefix.length()), params.getParams(nxt));
+      }
+    }
+    return result;
+  }
 
 
   @Override
@@ -341,13 +365,17 @@ public class SpellCheckComponent extends SearchComponent implements SolrCoreAwar
   }
 
   protected SolrSpellChecker getSpellChecker(SolrParams params) {
+    return spellCheckers.get(getDictionaryName(params));
+  }
+
+  private String getDictionaryName(SolrParams params) {
     String dictName = params.get(SPELLCHECK_DICT);
     if (dictName == null) {
       dictName = SolrSpellChecker.DEFAULT_DICTIONARY_NAME;
     }
-    return spellCheckers.get(dictName);
+    return dictName;
   }
-  
+
   /**
    * @return the spellchecker registered to a given name
    */

solr/src/java/org/apache/solr/spelling/AbstractLuceneSpellChecker.java

@@ -150,29 +150,30 @@ public abstract class AbstractLuceneSpellChecker extends SolrSpellChecker {
     return name;
   }
   
-  @SuppressWarnings("unchecked")
+  @Override
-  public SpellingResult getSuggestions(Collection<Token> tokens,
+  public SpellingResult getSuggestions(SpellingOptions options) throws IOException {
-                                       IndexReader reader, int count, boolean onlyMorePopular,
+    SpellingResult result = new SpellingResult(options.tokens);
-                                       boolean extendedResults)
+    IndexReader reader = determineReader(options.reader);
-          throws IOException {
-    SpellingResult result = new SpellingResult(tokens);
-    reader = determineReader(reader);
     Term term = field != null ? new Term(field, "") : null;
-    for (Token token : tokens) {
+    float theAccuracy = (options.accuracy == Float.MIN_VALUE) ? spellChecker.getAccuracy() : options.accuracy;
+    
+    int count = (int) Math.max(options.count, AbstractLuceneSpellChecker.DEFAULT_SUGGESTION_COUNT);
+    for (Token token : options.tokens) {
       String tokenText = new String(token.buffer(), 0, token.length());
-      String[] suggestions = spellChecker.suggestSimilar(tokenText, (int) Math.max(count, AbstractLuceneSpellChecker.DEFAULT_SUGGESTION_COUNT),
+      String[] suggestions = spellChecker.suggestSimilar(tokenText,
+              count,
             field != null ? reader : null, //workaround LUCENE-1295
             field,
-            onlyMorePopular);
+            options.onlyMorePopular, theAccuracy);
       if (suggestions.length == 1 && suggestions[0].equals(tokenText)) {
         //These are spelled the same, continue on
         continue;
       }
 
-      if (extendedResults == true && reader != null && field != null) {
+      if (options.extendedResults == true && reader != null && field != null) {
         term = term.createTerm(tokenText);
         result.add(token, reader.docFreq(term));
-        int countLimit = Math.min(count, suggestions.length);
+        int countLimit = Math.min(options.count, suggestions.length);
         for (int i = 0; i < countLimit; i++) {
           term = term.createTerm(suggestions[i]);
           result.add(token, suggestions[i], reader.docFreq(term));
@@ -180,8 +181,8 @@ public abstract class AbstractLuceneSpellChecker extends SolrSpellChecker {
       } else {
         if (suggestions.length > 0) {
           List<String> suggList = Arrays.asList(suggestions);
-          if (suggestions.length > count) {
+          if (suggestions.length > options.count) {
-            suggList = suggList.subList(0, count);
+            suggList = suggList.subList(0, options.count);
           }
           result.add(token, suggList);
         }

solr/src/java/org/apache/solr/spelling/SolrSpellChecker.java

@@ -70,46 +70,15 @@ public abstract class SolrSpellChecker {
    */
   public abstract void build(SolrCore core, SolrIndexSearcher searcher);
 
-  /**
-   * Assumes count = 1, onlyMorePopular = false, extendedResults = false
-   *
-   * @see #getSuggestions(Collection, org.apache.lucene.index.IndexReader, int, boolean, boolean)
-   */
-  public SpellingResult getSuggestions(Collection<Token> tokens, IndexReader reader) throws IOException {
-    return getSuggestions(tokens, reader, 1, false, false);
-  }
-
-  /**
-   * Assumes onlyMorePopular = false, extendedResults = false
-   *
-   * @see #getSuggestions(Collection, org.apache.lucene.index.IndexReader, int, boolean, boolean)
-   */
-  public SpellingResult getSuggestions(Collection<Token> tokens, IndexReader reader, int count) throws IOException {
-    return getSuggestions(tokens, reader, count, false, false);
-  }
-
-
-  /**
-   * Assumes count = 1.
-   *
-   * @see #getSuggestions(Collection, org.apache.lucene.index.IndexReader, int, boolean, boolean)
-   */
-  public SpellingResult getSuggestions(Collection<Token> tokens, IndexReader reader, boolean onlyMorePopular, boolean extendedResults) throws IOException {
-    return getSuggestions(tokens, reader, 1, onlyMorePopular, extendedResults);
-  }
 
   /**
    * Get suggestions for the given query.  Tokenizes the query using a field appropriate Analyzer.
    * The {@link SpellingResult#getSuggestions()} suggestions must be ordered by best suggestion first.
+   * <p/>
    *
-   * @param tokens          The Tokens to be spell checked.
+   * @param options The {@link SpellingOptions} to use
-   * @param reader          The (optional) IndexReader.  If there is not IndexReader, than extendedResults are not possible
+   * @return The {@link SpellingResult} suggestions
-   * @param count The maximum number of suggestions to return
+   * @throws IOException if there is an error producing suggestions
-   * @param onlyMorePopular  TODO
-   * @param extendedResults  TODO
-   * @throws IOException
    */
-  public abstract SpellingResult getSuggestions(Collection<Token> tokens, IndexReader reader, int count,
+  public abstract SpellingResult getSuggestions(SpellingOptions options) throws IOException;
-                                                boolean onlyMorePopular, boolean extendedResults)
-          throws IOException;
 }

solr/src/java/org/apache/solr/spelling/SpellingOptions.java

@@ -0,0 +1,94 @@
+package org.apache.solr.spelling;
+
+import org.apache.lucene.analysis.Token;
+import org.apache.lucene.index.IndexReader;
+import org.apache.solr.common.params.SolrParams;
+
+import java.util.Collection;
+/**
+ * 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.
+ */
+
+
+/**
+ *
+ *
+ **/
+public class SpellingOptions {
+
+  /**
+   * The tokens to spell check
+   */
+  public Collection<Token> tokens;
+  /**
+   * An optional {@link org.apache.lucene.index.IndexReader}
+   */
+  public IndexReader reader;
+  /**
+   * The number of suggestions to return, if there are any.  Defaults to 1.
+   */
+  public int count = 1;
+  /**
+   * Return only those results that are more popular, as defined by the implementation
+   */
+  public boolean onlyMorePopular;
+  /**
+   * Provide additional, per implementation, information about the results
+   */
+  public boolean extendedResults;
+
+  /**
+   * Optionally restrict the results to have a minimum accuracy level.  Per Implementation.
+   * By default set to Float.MIN_VALUE.
+   */
+  public float accuracy = Float.MIN_VALUE;
+
+  /**
+   * Any other custom params can be passed through.  May be null and is null by default.
+   */
+  public SolrParams customParams;
+
+  public SpellingOptions() {
+  }
+
+  //A couple of convenience ones
+  public SpellingOptions(Collection<Token> tokens, int count) {
+    this.tokens = tokens;
+    this.count = count;
+  }
+
+  public SpellingOptions(Collection<Token> tokens, IndexReader reader) {
+    this.tokens = tokens;
+    this.reader = reader;
+  }
+
+  public SpellingOptions(Collection<Token> tokens, IndexReader reader, int count) {
+    this.tokens = tokens;
+    this.reader = reader;
+    this.count = count;
+  }
+
+
+  public SpellingOptions(Collection<Token> tokens, IndexReader reader, int count, boolean onlyMorePopular, boolean extendedResults, float accuracy, SolrParams customParams) {
+    this.tokens = tokens;
+    this.reader = reader;
+    this.count = count;
+    this.onlyMorePopular = onlyMorePopular;
+    this.extendedResults = extendedResults;
+    this.accuracy = accuracy;
+    this.customParams = customParams;
+  }
+}

solr/src/test/org/apache/solr/handler/component/DummyCustomParamSpellChecker.java

@@ -0,0 +1,61 @@
+package org.apache.solr.handler.component;
+
+import org.apache.lucene.analysis.Token;
+import org.apache.solr.core.SolrCore;
+import org.apache.solr.search.SolrIndexSearcher;
+import org.apache.solr.spelling.SolrSpellChecker;
+import org.apache.solr.spelling.SpellingOptions;
+import org.apache.solr.spelling.SpellingResult;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Iterator;
+/**
+ * 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.
+ */
+
+
+/**
+ * A Dummy SpellChecker for testing purposes
+ *
+ **/
+public class DummyCustomParamSpellChecker extends SolrSpellChecker {
+
+  @Override
+  public void reload() throws IOException {
+
+  }
+
+  @Override
+  public void build(SolrCore core, SolrIndexSearcher searcher) {
+
+  }
+
+  @Override
+  public SpellingResult getSuggestions(SpellingOptions options) throws IOException {
+
+    SpellingResult result = new SpellingResult();
+    //just spit back out the results
+    Iterator<String> iterator = options.customParams.getParameterNamesIterator();
+    int i = 0;
+    while (iterator.hasNext()){
+      String name = iterator.next();
+      String value = options.customParams.get(name);
+      result.add(new Token(name, i++, i++),  Collections.singletonList(value));
+    }    
+    return result;
+  }
+}

solr/src/test/org/apache/solr/handler/component/SpellCheckComponentTest.java

@@ -24,6 +24,7 @@ import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.params.MapSolrParams;
 import org.apache.solr.common.params.ModifiableSolrParams;
+import org.apache.solr.common.params.SpellingParams;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.SimpleOrderedMap;
 import org.apache.solr.core.SolrCore;
@@ -33,7 +34,6 @@ import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.response.SolrQueryResponse;
 import org.apache.solr.spelling.AbstractLuceneSpellChecker;
 import org.apache.solr.spelling.IndexBasedSpellChecker;
-import org.apache.solr.util.AbstractSolrTestCase;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -133,9 +133,9 @@ public class SpellCheckComponentTest extends SolrTestCaseJ4 {
     assertTrue(cmdExec + " is not equal to " + "build",
             cmdExec.equals("build") == true);
     NamedList spellCheck = (NamedList) values.get("spellcheck");
-    assertTrue("spellCheck is null and it shouldn't be", spellCheck != null);
+    assertNotNull(spellCheck);
     NamedList suggestions = (NamedList) spellCheck.get("suggestions");
-    assertTrue("suggestions is null and it shouldn't be", suggestions != null);
+    assertNotNull(suggestions);
     NamedList document = (NamedList) suggestions.get("documemt");
     assertEquals(1, document.get("numFound"));
     assertEquals(0, document.get("startOffset"));
@@ -145,6 +145,50 @@ public class SpellCheckComponentTest extends SolrTestCaseJ4 {
     assertEquals("document", theSuggestion.iterator().next());
   }
 
+
+  @Test
+  public void testPerDictionary() throws Exception {
+    SolrCore core = h.getCore();
+    SearchComponent speller = core.getSearchComponent("spellcheck");
+    assertTrue("speller is null and it shouldn't be", speller != null);
+
+    ModifiableSolrParams params = new ModifiableSolrParams();
+    params.add(CommonParams.QT, "spellCheckCompRH");
+    params.add(SpellCheckComponent.SPELLCHECK_BUILD, "true");
+    params.add(CommonParams.Q, "documemt");
+    params.add(SpellCheckComponent.COMPONENT_NAME, "true");
+    params.add(SpellingParams.SPELLCHECK_DICT, "perDict");
+
+    params.add(SpellingParams.SPELLCHECK_PREFIX + ".perDict.foo", "bar");
+    params.add(SpellingParams.SPELLCHECK_PREFIX + ".perDict.bar", "foo");
+
+    SolrRequestHandler handler = core.getRequestHandler("spellCheckCompRH");
+    SolrQueryResponse rsp = new SolrQueryResponse();
+    handler.handleRequest(new LocalSolrQueryRequest(core, params), rsp);
+    NamedList values = rsp.getValues();
+
+    NamedList spellCheck = (NamedList) values.get("spellcheck");
+    NamedList suggestions = (NamedList) spellCheck.get("suggestions");
+    assertNotNull("suggestions", suggestions);
+    NamedList suggestion;
+    Collection<String> theSuggestion;
+    suggestion = (NamedList) suggestions.get("foo");
+    assertEquals(1, suggestion.get("numFound"));
+    assertEquals(0, suggestion.get("startOffset"));
+    assertEquals(suggestion.get("endOffset"), 1);
+    theSuggestion = (Collection<String>) suggestion.get("suggestion");
+    assertEquals(1, theSuggestion.size());
+    assertEquals("bar", theSuggestion.iterator().next());
+
+    suggestion = (NamedList) suggestions.get("bar");
+    assertEquals(1, suggestion.get("numFound"));
+    assertEquals(2, suggestion.get("startOffset"));
+    assertEquals(3, suggestion.get("endOffset"));
+    theSuggestion = (Collection<String>) suggestion.get("suggestion");
+    assertEquals(1, theSuggestion.size());
+    assertEquals("foo", theSuggestion.iterator().next());
+  }
+
   @Test
   public void testCollate() throws Exception {
     SolrCore core = h.getCore();

solr/src/test/org/apache/solr/spelling/FileBasedSpellCheckerTest.java

@@ -80,15 +80,16 @@ public class FileBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = core.getSearcher().get().getReader();
     Collection<Token> tokens = queryConverter.convert("fob");
-    SpellingResult result = checker.getSuggestions(tokens, reader);
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     Map<String, Integer> suggestions = result.get(tokens.iterator().next());
     Map.Entry<String, Integer> entry = suggestions.entrySet().iterator().next();
     assertTrue(entry.getKey() + " is not equal to " + "foo", entry.getKey().equals("foo") == true);
     assertTrue(entry.getValue() + " does not equal: " + SpellingResult.NO_FREQUENCY_INFO, entry.getValue() == SpellingResult.NO_FREQUENCY_INFO);
 
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     suggestions = result.get(tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
@@ -118,7 +119,9 @@ public class FileBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = core.getSearcher().get().getReader();
     Collection<Token> tokens = queryConverter.convert("Solar");
-    SpellingResult result = checker.getSuggestions(tokens, reader);
+
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     //should be lowercased, b/c we are using a lowercasing analyzer
     Map<String, Integer> suggestions = result.get(tokens.iterator().next());
@@ -128,8 +131,8 @@ public class FileBasedSpellCheckerTest extends SolrTestCaseJ4 {
     assertTrue(entry.getValue() + " does not equal: " + SpellingResult.NO_FREQUENCY_INFO, entry.getValue() == SpellingResult.NO_FREQUENCY_INFO);
 
     //test something not in the spell checker
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     suggestions = result.get(tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
@@ -160,7 +163,8 @@ public class FileBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = core.getSearcher().get().getReader();
     Collection<Token> tokens = queryConverter.convert("solar");
-    SpellingResult result = checker.getSuggestions(tokens, reader);
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     //should be lowercased, b/c we are using a lowercasing analyzer
     Map<String, Integer> suggestions = result.get(tokens.iterator().next());
@@ -170,10 +174,10 @@ public class FileBasedSpellCheckerTest extends SolrTestCaseJ4 {
     assertTrue(entry.getValue() + " does not equal: " + SpellingResult.NO_FREQUENCY_INFO, entry.getValue() == SpellingResult.NO_FREQUENCY_INFO);
 
 
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
   }
 }

solr/src/test/org/apache/solr/spelling/IndexBasedSpellCheckerTest.java

@@ -125,10 +125,11 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = searcher.getReader();
     Collection<Token> tokens = queryConverter.convert("documemt");
-    SpellingResult result = checker.getSuggestions(tokens, reader);
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     //should be lowercased, b/c we are using a lowercasing analyzer
-    Map<String, Integer> suggestions = result.get(tokens.iterator().next());
+    Map<String, Integer> suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("documemt is null and it shouldn't be", suggestions != null);
     assertTrue("documemt Size: " + suggestions.size() + " is not: " + 1, suggestions.size() == 1);
     Map.Entry<String, Integer> entry = suggestions.entrySet().iterator().next();
@@ -136,32 +137,33 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
     assertTrue(entry.getValue() + " does not equal: " + SpellingResult.NO_FREQUENCY_INFO, entry.getValue() == SpellingResult.NO_FREQUENCY_INFO);
 
     //test something not in the spell checker
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
 
     //test something that is spelled correctly
-    tokens = queryConverter.convert("document");
+    spellOpts.tokens = queryConverter.convert("document");
-    result = checker.getSuggestions(tokens, reader);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is null and it shouldn't be", suggestions == null);
 
     //Has multiple possibilities, but the exact exists, so that should be returned
-    tokens = queryConverter.convert("red");
+    spellOpts.tokens = queryConverter.convert("red");
-    result = checker.getSuggestions(tokens, reader, 2);
+    spellOpts.count = 2;
-    assertTrue("result is null and it shouldn't be", result != null);
+    result = checker.getSuggestions(spellOpts);
-    suggestions = result.get(tokens.iterator().next());
+    assertNotNull(result);
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
 
     //Try out something which should have multiple suggestions
-    tokens = queryConverter.convert("bug");
+    spellOpts.tokens = queryConverter.convert("bug");
-    result = checker.getSuggestions(tokens, reader, 2);
+    result = checker.getSuggestions(spellOpts);
-    assertTrue("result is null and it shouldn't be", result != null);
+    assertNotNull(result);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
-    assertTrue("suggestions is null and it shouldn't be", suggestions != null);
+    assertNotNull(suggestions);
     assertTrue("suggestions Size: " + suggestions.size() + " is not: " + 2, suggestions.size() == 2);
 
     entry = suggestions.entrySet().iterator().next();
@@ -198,10 +200,11 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = searcher.getReader();
     Collection<Token> tokens = queryConverter.convert("documemt");
-    SpellingResult result = checker.getSuggestions(tokens, reader, 1, false, true);
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader, 1, false, true, 0.5f, null);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     //should be lowercased, b/c we are using a lowercasing analyzer
-    Map<String, Integer> suggestions = result.get(tokens.iterator().next());
+    Map<String, Integer> suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("documemt is null and it shouldn't be", suggestions != null);
     assertTrue("documemt Size: " + suggestions.size() + " is not: " + 1, suggestions.size() == 1);
     Map.Entry<String, Integer> entry = suggestions.entrySet().iterator().next();
@@ -209,16 +212,16 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
     assertTrue(entry.getValue() + " does not equal: " + 2, entry.getValue() == 2);
 
     //test something not in the spell checker
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader, 1, false, true);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
 
-    tokens = queryConverter.convert("document");
+    spellOpts.tokens = queryConverter.convert("document");
-    result = checker.getSuggestions(tokens, reader, 1, false, true);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
     } finally {
       holder.decref();
@@ -304,10 +307,11 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
 
     IndexReader reader = searcher.getReader();
     Collection<Token> tokens = queryConverter.convert("flesh");
-    SpellingResult result = checker.getSuggestions(tokens, reader, 1, false, true);
+    SpellingOptions spellOpts = new SpellingOptions(tokens, reader, 1, false, true, 0.5f, null);
+    SpellingResult result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
     //should be lowercased, b/c we are using a lowercasing analyzer
-    Map<String, Integer> suggestions = result.get(tokens.iterator().next());
+    Map<String, Integer> suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("flesh is null and it shouldn't be", suggestions != null);
     assertTrue("flesh Size: " + suggestions.size() + " is not: " + 1, suggestions.size() == 1);
     Map.Entry<String, Integer> entry = suggestions.entrySet().iterator().next();
@@ -315,16 +319,16 @@ public class IndexBasedSpellCheckerTest extends SolrTestCaseJ4 {
     assertTrue(entry.getValue() + " does not equal: " + 1, entry.getValue() == 1);
 
     //test something not in the spell checker
-    tokens = queryConverter.convert("super");
+    spellOpts.tokens = queryConverter.convert("super");
-    result = checker.getSuggestions(tokens, reader, 1, false, true);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
 
-    tokens = queryConverter.convert("Caroline");
+    spellOpts.tokens = queryConverter.convert("Caroline");
-    result = checker.getSuggestions(tokens, reader, 1, false, true);
+    result = checker.getSuggestions(spellOpts);
     assertTrue("result is null and it shouldn't be", result != null);
-    suggestions = result.get(tokens.iterator().next());
+    suggestions = result.get(spellOpts.tokens.iterator().next());
     assertTrue("suggestions is not null and it should be", suggestions == null);
     } finally {
       holder.decref();

solr/src/test/test-files/solr/conf/solrconfig.xml

@@ -377,7 +377,11 @@
       <str name="comparatorClass">org.apache.solr.spelling.SampleComparator</str>
       <str name="buildOnCommit">true</str>
     </lst>
-
+    <lst name="spellchecker">
+      <str name="name">perDict</str>
+      <str name="classname">org.apache.solr.handler.component.DummyCustomParamSpellChecker</str>
+      <str name="field">lowerfilt</str>
+    </lst>
   </searchComponent>
 
   <searchComponent name="termsComp" class="org.apache.solr.handler.component.TermsComponent"/>