Drop java8 fallback

src/main/java/org/apache/ibatis/binding/MapperProxy.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -20,15 +20,13 @@
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodHandles.Lookup;
 import java.lang.invoke.MethodType;
-import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Map;
 
 import org.apache.ibatis.reflection.ExceptionUtil;
 import org.apache.ibatis.session.SqlSession;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -37,9 +35,6 @@
 public class MapperProxy<T> implements InvocationHandler, Serializable {
 
   private static final long serialVersionUID = -4724728412955527868L;
-  private static final int ALLOWED_MODES = MethodHandles.Lookup.PRIVATE | MethodHandles.Lookup.PROTECTED
-      | MethodHandles.Lookup.PACKAGE | MethodHandles.Lookup.PUBLIC;
-  private static final Constructor<Lookup> lookupConstructor;
   private static final Method privateLookupInMethod;
   private final SqlSession sqlSession;
   private final Class<T> mapperInterface;
@@ -52,29 +47,12 @@ public MapperProxy(SqlSession sqlSession, Class<T> mapperInterface, Map<Method,
   }
 
   static {
-    Method privateLookupIn;
     try {
-      privateLookupIn = MethodHandles.class.getMethod("privateLookupIn", Class.class, MethodHandles.Lookup.class);
+      privateLookupInMethod = MethodHandles.class.getMethod("privateLookupIn", Class.class, MethodHandles.Lookup.class);
     } catch (NoSuchMethodException e) {
-      privateLookupIn = null;
+      throw new IllegalStateException(
+          "There is no 'privateLookupIn(Class, Lookup)' method in java.lang.invoke.MethodHandles.", e);
     }
-    privateLookupInMethod = privateLookupIn;
-
-    Constructor<Lookup> lookup = null;
-    if (privateLookupInMethod == null) {
-      // JDK 1.8
-      try {
-        lookup = MethodHandles.Lookup.class.getDeclaredConstructor(Class.class, int.class);
-        lookup.setAccessible(true);
-      } catch (NoSuchMethodException e) {
-        throw new IllegalStateException(
-            "There is neither 'privateLookupIn(Class, Lookup)' nor 'Lookup(Class, int)' method in java.lang.invoke.MethodHandles.",
-            e);
-      } catch (Exception e) {
-        lookup = null;
-      }
-    }
-    lookupConstructor = lookup;
   }
 
   @Override
@@ -91,17 +69,13 @@ public Object invoke(Object proxy, Method method, Object[] args) throws Throwabl
 
   private MapperMethodInvoker cachedInvoker(Method method) throws Throwable {
     try {
-      return MapUtil.computeIfAbsent(methodCache, method, m -> {
+      return methodCache.computeIfAbsent(method, m -> {
         if (!m.isDefault()) {
           return new PlainMethodInvoker(new MapperMethod(mapperInterface, method, sqlSession.getConfiguration()));
         }
         try {
-          if (privateLookupInMethod == null) {
-            return new DefaultMethodInvoker(getMethodHandleJava8(method));
-          }
           return new DefaultMethodInvoker(getMethodHandleJava9(method));
-        } catch (IllegalAccessException | InstantiationException | InvocationTargetException
-            | NoSuchMethodException e) {
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
           throw new RuntimeException(e);
         }
       });
@@ -119,12 +93,6 @@ private MethodHandle getMethodHandleJava9(Method method)
         declaringClass);
   }
 
-  private MethodHandle getMethodHandleJava8(Method method)
-      throws IllegalAccessException, InstantiationException, InvocationTargetException {
-    final Class<?> declaringClass = method.getDeclaringClass();
-    return lookupConstructor.newInstance(declaringClass, ALLOWED_MODES).unreflectSpecial(method, declaringClass);
-  }
-
   interface MapperMethodInvoker {
     Object invoke(Object proxy, Method method, Object[] args, SqlSession sqlSession) throws Throwable;
   }

src/main/java/org/apache/ibatis/cache/TransactionalCacheManager.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2022 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -19,7 +19,6 @@
 import java.util.Map;
 
 import org.apache.ibatis.cache.decorators.TransactionalCache;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -53,7 +52,7 @@ public void rollback() {
   }
 
   private TransactionalCache getTransactionalCache(Cache cache) {
-    return MapUtil.computeIfAbsent(transactionalCaches, cache, TransactionalCache::new);
+    return transactionalCaches.computeIfAbsent(cache, TransactionalCache::new);
   }
 
 }

src/main/java/org/apache/ibatis/datasource/unpooled/UnpooledDataSource.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -31,7 +31,6 @@
 import javax.sql.DataSource;
 
 import org.apache.ibatis.io.Resources;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -233,7 +232,7 @@ private Connection doGetConnection(Properties properties) throws SQLException {
 
   private void initializeDriver() throws SQLException {
     try {
-      MapUtil.computeIfAbsent(registeredDrivers, driver, x -> {
+      registeredDrivers.computeIfAbsent(driver, x -> {
         Class<?> driverType;
         try {
           if (driverClassLoader != null) {

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

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -41,7 +41,6 @@
 import org.apache.ibatis.type.JdbcType;
 import org.apache.ibatis.type.TypeHandler;
 import org.apache.ibatis.type.TypeHandlerRegistry;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -156,8 +155,8 @@ private void assignKeysToParamMap(Configuration configuration, ResultSet rs, Res
     for (int i = 0; i < keyProperties.length; i++) {
       Entry<String, KeyAssigner> entry = getAssignerForParamMap(configuration, rsmd, i + 1, paramMap, keyProperties[i],
           keyProperties, true);
-      Entry<Iterator<?>, List<KeyAssigner>> iteratorPair = MapUtil.computeIfAbsent(assignerMap, entry.getKey(),
-          k -> MapUtil.entry(collectionize(paramMap.get(k)).iterator(), new ArrayList<>()));
+      Entry<Iterator<?>, List<KeyAssigner>> iteratorPair = assignerMap.computeIfAbsent(entry.getKey(),
+          k -> Map.entry(collectionize(paramMap.get(k)).iterator(), new ArrayList<>()));
       iteratorPair.getValue().add(entry.getValue());
     }
     long counter = 0;
@@ -193,7 +192,7 @@ private Entry<String, KeyAssigner> getAssignerForParamMap(Configuration config,
     if (keySet.contains(paramName)) {
       String argParamName = omitParamName ? null : paramName;
       String argKeyProperty = keyProperty.substring(firstDot + 1);
-      return MapUtil.entry(paramName, new KeyAssigner(config, rsmd, columnPosition, argParamName, argKeyProperty));
+      return Map.entry(paramName, new KeyAssigner(config, rsmd, columnPosition, argParamName, argKeyProperty));
     }
     if (singleParam) {
       return getAssignerForSingleParam(config, rsmd, columnPosition, paramMap, keyProperty, omitParamName);
@@ -210,7 +209,7 @@ private Entry<String, KeyAssigner> getAssignerForSingleParam(Configuration confi
     // Assume 'keyProperty' to be a property of the single param.
     String singleParamName = nameOfSingleParam(paramMap);
     String argParamName = omitParamName ? null : singleParamName;
-    return MapUtil.entry(singleParamName, new KeyAssigner(config, rsmd, columnPosition, argParamName, keyProperty));
+    return Map.entry(singleParamName, new KeyAssigner(config, rsmd, columnPosition, argParamName, keyProperty));
   }
 
   private static String nameOfSingleParam(Map<String, ?> paramMap) {

src/main/java/org/apache/ibatis/executor/resultset/DefaultResultSetHandler.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -66,7 +66,6 @@
 import org.apache.ibatis.type.JdbcType;
 import org.apache.ibatis.type.TypeHandler;
 import org.apache.ibatis.type.TypeHandlerRegistry;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -618,7 +617,7 @@ private void addPendingChildRelation(ResultSet rs, MetaObject metaResultObject,
     PendingRelation deferLoad = new PendingRelation();
     deferLoad.metaObject = metaResultObject;
     deferLoad.propertyMapping = parentMapping;
-    List<PendingRelation> relations = MapUtil.computeIfAbsent(pendingRelations, cacheKey, k -> new ArrayList<>());
+    List<PendingRelation> relations = pendingRelations.computeIfAbsent(cacheKey, k -> new ArrayList<>());
     // issue #255
     relations.add(deferLoad);
     ResultMapping previous = nextResultMaps.get(parentMapping.getResultSet());
@@ -820,7 +819,7 @@ private boolean applyArgNameBasedConstructorAutoMapping(ResultSetWrapper rsw, Re
           constructorArgs.add(value);
           final String mapKey = resultMap.getId() + ":" + columnPrefix;
           if (!autoMappingsCache.containsKey(mapKey)) {
-            MapUtil.computeIfAbsent(constructorAutoMappingColumns, mapKey, k -> new ArrayList<>()).add(columnName);
+            constructorAutoMappingColumns.computeIfAbsent(mapKey, k -> new ArrayList<>()).add(columnName);
           }
           columnNotFound = false;
           foundValues = value != null || foundValues;

src/main/java/org/apache/ibatis/plugin/Plugin.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2023 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -24,7 +24,6 @@
 import java.util.Set;
 
 import org.apache.ibatis.reflection.ExceptionUtil;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * @author Clinton Begin
@@ -74,7 +73,7 @@ private static Map<Class<?>, Set<Method>> getSignatureMap(Interceptor intercepto
     Signature[] sigs = interceptsAnnotation.value();
     Map<Class<?>, Set<Method>> signatureMap = new HashMap<>();
     for (Signature sig : sigs) {
-      Set<Method> methods = MapUtil.computeIfAbsent(signatureMap, sig.type(), k -> new HashSet<>());
+      Set<Method> methods = signatureMap.computeIfAbsent(sig.type(), k -> new HashSet<>());
       try {
         Method method = sig.type().getMethod(sig.method(), sig.args());
         methods.add(method);

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

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2023 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -18,8 +18,6 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
-import org.apache.ibatis.util.MapUtil;
-
 public class DefaultReflectorFactory implements ReflectorFactory {
   private boolean classCacheEnabled = true;
   private final ConcurrentMap<Class<?>, Reflector> reflectorMap = new ConcurrentHashMap<>();
@@ -41,7 +39,7 @@ public void setClassCacheEnabled(boolean classCacheEnabled) {
   public Reflector findForClass(Class<?> type) {
     if (classCacheEnabled) {
       // synchronized (type) removed see issue #461
-      return MapUtil.computeIfAbsent(reflectorMap, type, Reflector::new);
+      return reflectorMap.computeIfAbsent(type, Reflector::new);
     }
     return new Reflector(type);
   }

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

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2024 the original author or authors.
+ *    Copyright 2009-2025 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -43,7 +43,6 @@
 import org.apache.ibatis.reflection.invoker.MethodInvoker;
 import org.apache.ibatis.reflection.invoker.SetFieldInvoker;
 import org.apache.ibatis.reflection.property.PropertyNamer;
-import org.apache.ibatis.util.MapUtil;
 
 /**
  * This class represents a cached set of class definition information that allows for easy mapping between property
@@ -155,7 +154,7 @@ private void addSetMethods(Method[] methods) {
 
   private void addMethodConflict(Map<String, List<Method>> conflictingMethods, String name, Method method) {
     if (isValidPropertyName(name)) {
-      List<Method> list = MapUtil.computeIfAbsent(conflictingMethods, name, k -> new ArrayList<>());
+      List<Method> list = conflictingMethods.computeIfAbsent(name, k -> new ArrayList<>());
       list.add(method);
     }
   }