MyBatis测试表达式中的AND运算符是否在评估期间短路？

Question

Is the AND keyword in test expressions in MyBatis implemented using a short-circuit? For example, I have written the following:

<when test="pagingInstruction != null
            and pagingInstruction.direction.toString() == 'FORWARD'">
...
</when>

If the first operand resolves to false, will the second operand be ignored? (I'm using MyBatis v3.0.4.)

Answer 1

Although it is not stated in the reference doc that the test attribute of the when element short circuits, the reference doc includes an example that only works if the test attribute of the when element short circuits.

The example is similar to yours; here it is:

... stuff
<when test="author != null and author.name != null">

The easiest way to resolve your question might be to create some simple unit tests to determine how myBatis treats the "and".

Also, you may need to test that pageInstruction.direction is not null before calling pageInstruction.direction.toString() .