elasticsearch IK分词器扩展词典、停用词典、同义词典malformed_input_exception

elasticsearch IK分词器在扩展词典、停用词典、同义词典时需要创建文件，如果提示以下异常malformed_input_exception
一般是因为文件编码格式不正确，应该修改成UTF-8
{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "failed to build synonyms"
      }
    ],
    "type": "illegal_argument_exception",
    "reason": "failed to build synonyms",
    "caused_by": {
      "type": "malformed_input_exception",
      "reason": "Input length = 1"
    }
  },
  "status": 400
}