feat: add support nested types for MappedStatementTypes.java

mybatis-flex-core/src/main/java/com/mybatisflex/core/mybatis/MappedStatementTypes.java

@@ -15,23 +15,32 @@
  */
 package com.mybatisflex.core.mybatis;
 
+import java.util.Stack;
+
 public class MappedStatementTypes {
 
     private MappedStatementTypes() {
     }
 
-    private static final ThreadLocal<Class<?>> currentTypeTL = new ThreadLocal<>();
+    private static final ThreadLocal<Stack<Class<?>>> currentTypeTL = ThreadLocal.withInitial(Stack::new);
 
     public static void setCurrentType(Class<?> type) {
-        currentTypeTL.set(type);
+        currentTypeTL.get().push(type);
     }
 
     public static Class<?> getCurrentType() {
-        return currentTypeTL.get();
+        Stack<Class<?>> stack = currentTypeTL.get();
+        return stack.isEmpty() ? null : stack.lastElement();
     }
 
     public static void clear() {
+        Stack<Class<?>> stack = currentTypeTL.get();
+        if (!stack.isEmpty()) {
+            stack.pop();
+        }
+        if (stack.isEmpty()) {
             currentTypeTL.remove();
         }
+    }
 
 }

mybatis-flex-core/src/test/java/com/mybatisflex/core/util/MappedStatementTypesTest.java

@@ -0,0 +1,32 @@
+package com.mybatisflex.core.util;
+
+import com.mybatisflex.core.mybatis.MappedStatementTypes;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class MappedStatementTypesTest {
+
+    @Test
+    public void test() {
+        MappedStatementTypes.clear();
+
+        MappedStatementTypes.setCurrentType(String.class);
+        MappedStatementTypes.setCurrentType(MappedStatementTypesTest.class);
+        MappedStatementTypes.setCurrentType(StringUtilTest.class);
+
+        Assert.assertEquals(StringUtilTest.class, MappedStatementTypes.getCurrentType());
+        System.out.println(MappedStatementTypes.getCurrentType());
+        MappedStatementTypes.clear();
+
+        Assert.assertEquals(MappedStatementTypesTest.class, MappedStatementTypes.getCurrentType());
+        System.out.println(MappedStatementTypes.getCurrentType());
+        MappedStatementTypes.clear();
+
+        Assert.assertEquals(String.class, MappedStatementTypes.getCurrentType());
+        System.out.println(MappedStatementTypes.getCurrentType());
+        MappedStatementTypes.clear();
+
+        Assert.assertNull(MappedStatementTypes.getCurrentType());
+        System.out.println(MappedStatementTypes.getCurrentType());
+    }
+}