Refactoring: moved getLanguageDriver() from MapperBuilderAssistant to Configuration

- In ProviderSqlSource, it is better not to assume the driver is already registered.
- Replaced Class#newInstance() with Constructor#newInstance().

Author: harawata

src/main/java/org/apache/ibatis/builder/MapperBuilderAssistant.java

@@ -457,13 +457,12 @@ public ResultMapping buildResultMapping(Class<?> resultType, String property, St
       nestedResultMap, notNullColumn, columnPrefix, typeHandler, flags, null, null, configuration.isLazyLoadingEnabled());
   }
 
+  /**
+   * @deprecated Use {@link Configuration#getLanguageDriver(Class)}
+   */
+  @Deprecated
   public LanguageDriver getLanguageDriver(Class<? extends LanguageDriver> langClass) {
-    if (langClass != null) {
-      configuration.getLanguageRegistry().register(langClass);
-    } else {
-      langClass = configuration.getLanguageRegistry().getDefaultDriverClass();
-    }
-    return configuration.getLanguageRegistry().getDriver(langClass);
+    return configuration.getLanguageDriver(langClass);
   }
 
   /** Backward compatibility signature. */

src/main/java/org/apache/ibatis/builder/annotation/MapperAnnotationBuilder.java

@@ -387,7 +387,7 @@ private LanguageDriver getLanguageDriver(Method method) {
     if (lang != null) {
       langClass = lang.value();
     }
-    return assistant.getLanguageDriver(langClass);
+    return configuration.getLanguageDriver(langClass);
   }
 
   private Class<?> getParameterType(Method method) {

src/main/java/org/apache/ibatis/builder/annotation/ProviderSqlSource.java

@@ -59,9 +59,7 @@ public ProviderSqlSource(Configuration configuration, Object provider, Class<?>
     try {
       this.configuration = configuration;
       Lang lang = mapperMethod == null ? null : mapperMethod.getAnnotation(Lang.class);
-      this.languageDriver = lang == null ?
-          configuration.getLanguageRegistry().getDefaultDriver() :
-          configuration.getLanguageRegistry().getDriver(lang.value());
+      this.languageDriver = configuration.getLanguageDriver(lang == null ? null : lang.value());
       this.providerType = (Class<?>) provider.getClass().getMethod("type").invoke(provider);
       providerMethodName = (String) provider.getClass().getMethod("method").invoke(provider);
 

src/main/java/org/apache/ibatis/builder/xml/XMLStatementBuilder.java

@@ -197,7 +197,7 @@ private LanguageDriver getLanguageDriver(String lang) {
     if (lang != null) {
       langClass = resolveClass(lang);
     }
-    return builderAssistant.getLanguageDriver(langClass);
+    return configuration.getLanguageDriver(langClass);
   }
 
 }

src/main/java/org/apache/ibatis/scripting/LanguageDriverRegistry.java

@@ -31,13 +31,13 @@ public void register(Class<? extends LanguageDriver> cls) {
     if (cls == null) {
       throw new IllegalArgumentException("null is not a valid Language Driver");
     }
-    if (!LANGUAGE_DRIVER_MAP.containsKey(cls)) {
+    LANGUAGE_DRIVER_MAP.computeIfAbsent(cls, k -> {
       try {
-        LANGUAGE_DRIVER_MAP.put(cls, cls.newInstance());
+        return k.getDeclaredConstructor().newInstance();
       } catch (Exception ex) {
         throw new ScriptingException("Failed to load language driver for " + cls.getName(), ex);
       }
-    }
+    });
   }
 
   public void register(LanguageDriver instance) {

src/main/java/org/apache/ibatis/session/Configuration.java

@@ -536,6 +536,14 @@ public LanguageDriver getDefaultScriptingLanguageInstance() {
     return languageRegistry.getDefaultDriver();
   }
 
+  public LanguageDriver getLanguageDriver(Class<? extends LanguageDriver> langClass) {
+    if (langClass == null) {
+      return languageRegistry.getDefaultDriver();
+    }
+    languageRegistry.register(langClass);
+    return languageRegistry.getDriver(langClass);
+  }
+
   /**
    * @deprecated Use {@link #getDefaultScriptingLanguageInstance()}
    */