This is a patch to enable user dictionary when using custom Japanese (lucene-kuromoji) at Confluence. The filepath for user dictionary is <confluence.home>/config/userdict_ja.txt. This patch has compatibility with Confluence 5.4.4 and Confluence 5.5.

confluence-userdict-ja.patch

diff --git confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/ConfluenceAnalyzer.java confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/ConfluenceAnalyzer.java
index a4cc059..32fdd1c 100644
--- confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/ConfluenceAnalyzer.java
+++ confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/ConfluenceAnalyzer.java
@@ -12,7 +12,7 @@ import org.apache.lucene.analysis.cz.CzechAnalyzer;
 import org.apache.lucene.analysis.de.GermanAnalyzer;
 import org.apache.lucene.analysis.el.GreekAnalyzer;
 import org.apache.lucene.analysis.fr.FrenchAnalyzer;
-import org.apache.lucene.analysis.ja.JapaneseAnalyzer;
+import com.atlassian.confluence.search.lucene.analyzers.ConfluenceJapaneseAnalyzer;
 import org.apache.lucene.analysis.ru.RussianAnalyzer;
 import org.apache.lucene.analysis.standard.StandardAnalyzer;

@@ -31,7 +31,7 @@ public class ConfluenceAnalyzer extends AnalyzerWrapper
         analyzers.put(Settings.GERMAN, new GermanAnalyzer(BonnieConstants.LUCENE_VERSION));
         analyzers.put(Settings.CHINESE, new StandardAnalyzer(BonnieConstants.LUCENE_VERSION));
         analyzers.put(Settings.CJK, new CJKAnalyzer(BonnieConstants.LUCENE_VERSION));
-        analyzers.put(Settings.CUSTOM_JAPANESE, new JapaneseAnalyzer(BonnieConstants.LUCENE_VERSION));
+        analyzers.put(Settings.CUSTOM_JAPANESE, new ConfluenceJapaneseAnalyzer(BonnieConstants.LUCENE_VERSION));
         analyzers.put(Settings.FRENCH, new FrenchAnalyzer(BonnieConstants.LUCENE_VERSION));
         analyzers.put(Settings.BRAZILIAN, new BrazilianAnalyzer(BonnieConstants.LUCENE_VERSION));
         analyzers.put(Settings.CZECH, new CzechAnalyzer(BonnieConstants.LUCENE_VERSION));
diff --git confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/analyzers/ConfluenceJapaneseAnalyzer.java confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/analyzers/ConfluenceJapaneseAnalyzer.java
new file mode 100644
index 0000000..e89f568
--- /dev/null
+++ confluence-project/confluence-core/confluence/src/java/com/atlassian/confluence/search/lucene/analyzers/ConfluenceJapaneseAnalyzer.java
@@ -0,0 +1,35 @@
+package com.atlassian.confluence.search.lucene.analyzers;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+
+import com.atlassian.config.bootstrap.AtlassianBootstrapManager;
+
+import org.apache.lucene.analysis.ja.JapaneseAnalyzer;
+import org.apache.lucene.analysis.ja.JapaneseTokenizer;
+import org.apache.lucene.analysis.ja.dict.UserDictionary;
+import org.apache.lucene.util.Version;
+
+/**
+ * Analyzer for Japanese that uses morphological analysis with UserDictionary.
+ */
+public class ConfluenceJapaneseAnalyzer extends JapaneseAnalyzer
+{
+    private static UserDictionary userDict;
+
+    static {
+        try {
+            AtlassianBootstrapManager bootstrapManager = com.atlassian.config.util.BootstrapUtils.getBootstrapManager();
+            String home = bootstrapManager.getConfiguredApplicationHome();
+            String userDictPath = home + File.separator + "config" + File.separator + "userdict_ja.txt";
+            userDict = new UserDictionary(new FileReader(new File(userDictPath)));
+        } catch (IOException e) {
+            userDict = null;
+        }
+    }
+
+    public ConfluenceJapaneseAnalyzer (final Version version) {
+        super(version, userDict, JapaneseTokenizer.DEFAULT_MODE, JapaneseAnalyzer.getDefaultStopSet(), JapaneseAnalyzer.getDefaultStopTags());
+    }
+}