Adjust MyBatisSystemException to Spring 6

Since Spring 6, `org.springframework.core.NestedRuntimeException` no longer includes the message of the wrapped exception.

spring-projects/spring-framework#25162

Should fix mybatisgh-887

Author: harawata

src/main/java/org/mybatis/spring/MyBatisExceptionTranslator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2022 the original author or authors.
+ * Copyright 2010-2023 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.
@@ -82,8 +82,12 @@ public DataAccessException translateExceptionIfPossible(RuntimeException e) {
     if (e instanceof PersistenceException) {
       // Batch exceptions come inside another PersistenceException
       // recursion has a risk of infinite loop so better make another if
+      String msg = e.getMessage();
       if (e.getCause() instanceof PersistenceException) {
         e = (PersistenceException) e.getCause();
+        if (msg == null) {
+          msg = e.getMessage();
+        }
       }
       if (e.getCause() instanceof SQLException) {
         this.initExceptionTranslator();
@@ -94,7 +98,7 @@ public DataAccessException translateExceptionIfPossible(RuntimeException e) {
       } else if (e.getCause() instanceof TransactionException) {
         throw (TransactionException) e.getCause();
       }
-      return new MyBatisSystemException(e);
+      return new MyBatisSystemException(msg, e);
     }
     return null;
   }

src/main/java/org/mybatis/spring/MyBatisSystemException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2022 the original author or authors.
+ * Copyright 2010-2023 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.
@@ -31,8 +31,8 @@ public class MyBatisSystemException extends UncategorizedDataAccessException {
 
   private static final long serialVersionUID = -5284728621670758939L;
 
-  public MyBatisSystemException(Throwable cause) {
-    super(null, cause);
+  public MyBatisSystemException(String msg, Throwable cause) {
+    super(msg, cause);
   }
 
 }