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Posted to user-zh@flink.apache.org by bigdata <11...@qq.com> on 2021/01/18 04:02:49 UTC

flink sql hop函数使用udaf，跟踪源码对merge方法进行参数校验时问题

你好：
&nbsp; &nbsp; flink1.10.1 sql在使用hop后并将udaf中merge方法名修改正确后，报如下错：为什么会说找不到匹配的merge方法呢
org.apache.flink.table.planner.codegen.CodeGenException: No matching merge method found for AggregateFunction com.autoai.cns.udaf.PercentileUDAF'
跟踪merge 参数校验源码思路：
1、ImperativeAggCodeGen类的checkNeededMethods方法中if (needMerge)&nbsp; &nbsp;getUserDefinedMethod 2、UserDefinedFunctionUtils类的getUserDefinedMethod方法中，当校验merge第二个参数时（代码详见下面merge）为false,进而导致报错，如何解决？还是说这是flink的一个bug
parameterClassEquals(methodSignature(i), clazz) ||
    parameterDataTypeEquals(internalTypes(i), dataTypes(i))


代码如下：
def merge(accumulator: ListBuffer[Float], its: Iterable[ListBuffer[Float]]): Unit = {
  its.foreach(i =&gt; accumulator ++ i)
}