WARNING: An illegal reflective access operation has occurred -> when using public method in non public class

[filiphr]

MyBatis version

3.5.6

Database vendor and version

Not important

Steps to reproduce

1. Create input parameter to be Collections.emptyList()
2. Use input parameter in a test expression in XML e.g. parameter.isEmpty()

Expected result

No illegal reflective access warning

Actual result

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.apache.ibatis.ognl.AccessibleObjectHandlerPreJDK9 (file:/~/.m2/repository/org/mybatis/mybatis/3.5.6/mybatis-3.5.6.jar) to method java.util.Collections$EmptyList.isEmpty()
WARNING: Please consider reporting this to the maintainers of org.apache.ibatis.ognl.AccessibleObjectHandlerPreJDK9
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

[filiphr]

The problem also occurs on 3.5.7.

I also run with --illegal-access=debug and the entire stacktrace is:

WARNING: Illegal reflective access by org.apache.ibatis.ognl.AccessibleObjectHandlerPreJDK9 (file:/Users/filiphr/.m2/repository/org/mybatis/mybatis/3.5.7/mybatis-3.5.7.jar) to method java.util.Collections$EmptyList.isEmpty()
	at org.apache.ibatis.ognl.AccessibleObjectHandlerPreJDK9.setAccessible(AccessibleObjectHandlerPreJDK9.java:58)
	at org.apache.ibatis.ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:1232)
	at org.apache.ibatis.ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1979)
	at org.apache.ibatis.ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)
	at org.apache.ibatis.ognl.OgnlRuntime.callMethod(OgnlRuntime.java:2055)
	at org.apache.ibatis.ognl.ASTMethod.getValueBody(ASTMethod.java:97)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.ASTChain.getValueBody(ASTChain.java:141)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.ASTNot.getValueBody(ASTNot.java:49)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.ASTAnd.getValueBody(ASTAnd.java:61)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.ASTOr.getValueBody(ASTOr.java:61)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:586)
	at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:550)
	at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:46)
	at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32)
	at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:34)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.lambda$apply$0(MixedSqlNode.java:32)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32)
	at org.apache.ibatis.scripting.xmltags.TrimSqlNode.apply(TrimSqlNode.java:55)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.lambda$apply$0(MixedSqlNode.java:32)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32)

[harawata]

Hello @filiphr ,

Please use <if test="parameter.empty"> or <if test="parameter.isEmpty"> instead.

isEmpty is one of the Pseudo-Properties for Collections.

Duplicate of #2383

[filiphr]

Thanks for the hint @harawata. I changed to isEmpty and it works fine without any warnings.

However, I still think that the issue will happen for non collections in a similar situation, a public method on a non public class

[harawata]

Glad to know it worked!

Test expressions are evaluated by OGNL, so if you think there is a room for improvement, submit the enhancement request to their tracker : https://github.com/jkuhnert/ognl/issues

[harawata]

This should be fixed by #2423

The OGNL issue is orphan-oss/ognl#144 (big thanks to @Farbfetzen !)

You can verify the fix with 3.5.10-SNAPSHOT .
If there still is an issue with the snapshot, please report the details.

Thank you for the report!

[filiphr]

That is great to hear @harawata. Thanks for letting me know