Merge CaseInsensitiveConcurrentMap into NullableKeyConcurrentMap

h2/src/main/org/h2/engine/Database.java

@@ -73,7 +73,6 @@ import org.h2.util.SourceCompiler;
 import org.h2.util.StringUtils;
 import org.h2.util.TempFileDeleter;
 import org.h2.util.Utils;
-import org.h2.value.CaseInsensitiveConcurrentMap;
 import org.h2.value.CaseInsensitiveMap;
 import org.h2.value.CompareMode;
 import org.h2.value.NullableKeyConcurrentMap;
@@ -2860,9 +2859,7 @@ public class Database implements DataHandler {
      * @return the hash map
      */
     public <V> ConcurrentHashMap<String, V> newConcurrentStringMap() {
-        return dbSettings.databaseToUpper ?
-                new NullableKeyConcurrentMap<V>() :
-                new CaseInsensitiveConcurrentMap<V>();
+        return new NullableKeyConcurrentMap<>(!dbSettings.databaseToUpper);
     }
 
     /**

h2/src/main/org/h2/value/CaseInsensitiveConcurrentMap.java

-/*
- * Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
- * and the EPL 1.0 (http://h2database.com/html/license.html).
- * Initial Developer: H2 Group
- */
-package org.h2.value;
-
-import java.util.concurrent.ConcurrentHashMap;
-import org.h2.util.StringUtils;
-
-/**
- * A concurrent hash map with a case-insensitive string key, that also allows
- * NULL as a key.
- *
- * @param <V> the value type
- */
-public class CaseInsensitiveConcurrentMap<V> extends ConcurrentHashMap<String, V> {
-
-    private static final long serialVersionUID = 1L;
-    private static final String NULL = new String(new byte[0]);
-
-    @Override
-    public V get(Object key) {
-        return super.get(toUpper(key));
-    }
-
-    @Override
-    public V put(String key, V value) {
-        return super.put(toUpper(key), value);
-    }
-
-    @Override
-    public boolean containsKey(Object key) {
-        return super.containsKey(toUpper(key));
-    }
-
-    @Override
-    public V remove(Object key) {
-        return super.remove(toUpper(key));
-    }
-
-    private static String toUpper(Object key) {
-        return key == null ? NULL : StringUtils.toUpperEnglish(key.toString());
-    }
-
-}

h2/src/main/org/h2/value/NullableKeyConcurrentMap.java

@@ -7,15 +7,29 @@ package org.h2.value;
 
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.h2.util.StringUtils;
+
 /**
- * A concurrent hash map that allows null keys
+ * A concurrent hash map with string keys that allows null keys.
  *
  * @param <V> the value type
  */
 public class NullableKeyConcurrentMap<V> extends ConcurrentHashMap<String, V> {
 
     private static final long serialVersionUID = 1L;
-    private static final String NULL = new String(new byte[0]);
+    private static final String NULL = new String();
+
+    private final boolean toUpper;
+
+    /**
+     * Create new instance of map.
+     *
+     * @param toUpper
+     *                    whether keys should be converted to upper case
+     */
+    public NullableKeyConcurrentMap(boolean toUpper) {
+        this.toUpper = toUpper;
+    }
 
     @Override
     public V get(Object key) {
@@ -37,8 +51,12 @@ public class NullableKeyConcurrentMap<V> extends ConcurrentHashMap<String, V> {
         return super.remove(toUpper(key));
     }
 
-    private static String toUpper(Object key) {
-        return key == null ? NULL : key.toString();
+    private String toUpper(Object key) {
+        if (key == null) {
+            return NULL;
+        }
+        String s = key.toString();
+        return toUpper ? StringUtils.toUpperEnglish(s) : s;
     }
 
 }