Merge pull request #1476 from kezhenxu94/polishing-remove-redundant-x

remove redundant imports and initializer

Author: kazuki43zoo

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

@@ -18,7 +18,6 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;

src/main/java/org/apache/ibatis/executor/keygen/Jdbc3KeyGenerator.java

@@ -120,7 +120,7 @@ private void assignKeysToParam(final Configuration configuration, ResultSet rs,
     final TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
     final ResultSetMetaData rsmd = rs.getMetaData();
     // Wrap the parameter in Collection to normalize the logic.
-    Collection<?> paramAsCollection = null;
+    Collection<?> paramAsCollection;
     if (param instanceof Object[]) {
       paramAsCollection = Arrays.asList((Object[]) param);
     } else if (!(param instanceof Collection)) {

src/main/java/org/apache/ibatis/executor/loader/ResultLoaderMap.java

@@ -224,7 +224,7 @@ private Configuration getConfiguration() {
         throw new ExecutorException("Cannot get Configuration as configuration factory was not set.");
       }
 
-      Object configurationObject = null;
+      Object configurationObject;
       try {
         final Method factoryMethod = this.configurationFactory.getDeclaredMethod(FACTORY_METHOD);
         if (!Modifier.isStatic(factoryMethod.getModifiers())) {

src/main/java/org/apache/ibatis/reflection/TypeParameterResolver.java

@@ -134,8 +134,8 @@ private static Type[] resolveWildcardTypeBounds(Type[] bounds, Type srcType, Cla
   }
 
   private static Type resolveTypeVar(TypeVariable<?> typeVar, Type srcType, Class<?> declaringClass) {
-    Type result = null;
-    Class<?> clazz = null;
+    Type result;
+    Class<?> clazz;
     if (srcType instanceof Class) {
       clazz = (Class<?>) srcType;
     } else if (srcType instanceof ParameterizedType) {

src/main/java/org/apache/ibatis/scripting/xmltags/XMLScriptBuilder.java

@@ -65,7 +65,7 @@ private void initNodeHandlerMap() {
 
   public SqlSource parseScriptNode() {
     MixedSqlNode rootSqlNode = parseDynamicTags(context);
-    SqlSource sqlSource = null;
+    SqlSource sqlSource;
     if (isDynamic) {
       sqlSource = new DynamicSqlSource(configuration, rootSqlNode);
     } else {