java - Apache CollectionUtils exist method in MyBatis XML

Question

Getting an error while trying the below code in MyBatis XML. this is part of my select query, which pull fruit price. The fruit name should be APPLE and it should belongs to the fruit list.

<if test="@org.apache.commons.collections.CollectionUtils@exists(param.getFruitList(), n -> n.equals('APPLE'))">
     tbl.price
 </if>

Below is the error I got.

Invoking @handleDefaultException method: Caused by:org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression '@org.apache.commons.collections.CollectionUtils@exists())'. Cause: org.apache.ibatis.ognl.ExpressionSyntaxException: Malformed OGNL expression: @org.apache.commons.collections.CollectionUtils@exists

question from:https://stackoverflow.com/questions/66048416/apache-collectionutils-exist-method-in-mybatis-xml

Answer 1

My understanding is that MyBatis's expression parser for XML is unable to handle lambdas/method references. You can try and create a helper method, something like

public static boolean helper(List<String> l) {
    return CollectionUtils.exists(l, "APPLE"::equals);
}

then refer it in the XML:

<if test="@some.package.Utils@helper(param.getFruitList())">
     tbl.price
</if>