elasticsearch-painless - 如何从无痛脚本中提取参数长度

Question

嗨，我想知道如何从无痛脚本中提取数组长度？

{
   "script": {
   "lang": "painless",
     "source": "what should be here???) { 
"params": {
  "plus": ["a","b","c"],   //how to retrieve 3 as plus length?
}
 }

Answer 1

params是一个HashMap，其中plus是一个ArrayList。您可以通过以下方式获取其长度：

"script": {
  "lang": "painless",
  "inline": "return params.plus.size()",
  "params": {
    "plus": ["a","b","c"]
  }
}