Invalid error message 'Two methods with same method sigunature but not providing classes assignable?' in System.err

[vlastimil-dolejs]

OgnlRuntime writes this error to system.err:

Two methods with same method signature but not providing classes assignable? "public abstract boolean java.util.List.isEmpty()" and "public boolean java.util.AbstractCollection.isEmpty()" please report!

This condition in my mapper causes the problem:
<if test="conditions != null &amp;&amp; !conditions.isEmpty()">

conditions variable is an java.util.Collections.singletonList(). When I change this variable to ArrayList, error disapears.

[harawata]

Hi,

It's OGNL that outputs the message.
I could reproduce it with the following code that does not depend on MyBatis.

  @Test
  public void testEmptyCheck2() throws Exception {
    String expressiosn = "list.isEmpty()";
    Object expr = Ognl.parseExpression(expressiosn);
    OgnlContext ctx = new OgnlContext();
    List<String> list = Collections.singletonList("string");
    ctx.put("list", list);
    Object value = Ognl.getValue(expr, ctx);
  }

I did a manual bisect on OGNL and it seems to be your PR that
triggered this issue. :)
You should report this to OGNL.

[kazuki43zoo]

Hi @harawata

A cause of this issue is OGNL implementation. However the MyBatis use repackaging classes. Therefore I think better this issue is keeping a open status until apply a bug fix OGNL.
What do you think ?

[harawata]

Okay. But I will lock the thread if we start getting 'me too' comments like the last one ;)

[kazuki43zoo]

I've added new label(bug on dependency library).

[kazuki43zoo]

Hi @vlastimil-dolejs, Could you report this issue to OGNL ?

[nusan]

when will fix this bug， waiting。

[wushp]

waiting +1;

[harawata]

😔
orphan-oss/ognl#35 Please wait there.

[harawata]

The waiting is over!
This issue has been resolved in OGNL 3.1.16 which will be included in MyBatis 3.4.6.
Please try the latest 3.4.6-SNAPSHOT and verify the fix before the final release.