Output in System.err 'Two methods with same method

[harawata]

Here is a repro:

  @Test
  public void test() 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);
    Assert.assertFalse((Boolean)value);
  }

The above test passes, but the following message is output in 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!

• The line that outputs the message is here.
• This seems to be a side effect of ca37319 .

This was reported on MyBatis tracker a while ago.

[PatrickGotthard]

Is there a chance that this could be fixed soon? At least every MyBatis user will get this error message when checking whether a collection is filled.

[lukaszlenart]

To be honest ... I have no idea how to fix that and I think the original authors also didn't take into account that the interfaces could have a real methods some day ...

[lukaszlenart]

The only idea I have is to remove this warning ... right now it's a valid case :)

[PatrickGotthard]

It is possible to check whether a method is a default method. Maybe it is possible to add this check to the code.

[lukaszlenart]

but not when using JDK7 as a source target.

[PatrickGotthard]

Hi Lukasz,

you're absolutely right. Maybe using a logging framework instead of System.err is also an option?

Regards,
Patrick