elasticsearch-river-jdbc：如何使用类型映射将json字符串映射到json对象

Question

我使用elasticsearch-river-jdbc从mysql导入数据，我有一个字符串字段，此字段中的数据是一个json字符串（如下所示：'[{“id”：1}]'），i想要将字符串映射到elasticsearch中的对象，有谁知道如何做到这一点？

我使用type_mappping来映射字段：

"type_mapping":
  {
      "postsInfo":
          {"properties":
            {
                "forums":{
                    "type":"object"
                }
            }
          }
  }

但是弹性搜索会抛出异常：

org.elasticsearch.index.mapper.MapperParsingException: object mapping for [postsInfo] tried to parse field [forums] as object, but got EOF, has a concrete value been provided to it?
at org.elasticsearch.index.mapper.object.ObjectMapper.parse(ObjectMapper.java:495)
at org.elasticsearch.index.mapper.DocumentMapper.parse(DocumentMapper.java:544)
at org.elasticsearch.index.mapper.DocumentMapper.parse(DocumentMapper.java:493)
at org.elasticsearch.index.shard.IndexShard.prepareIndex(IndexShard.java:480)
at org.elasticsearch.action.bulk.TransportShardBulkAction.shardIndexOperation(TransportShardBulkAction.java:423)
at org.elasticsearch.action.bulk.TransportShardBulkAction.shardOperationOnPrimary(TransportShardBulkAction.java:149)
at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$AsyncShardOperationAction.performOnPrimary(TransportShardReplicationOperationAction.java:515)
at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$AsyncShardOperationAction$1.run(TransportShardReplicationOperationAction.java:422)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)

我有谷歌很长一段时间，但没有找到解决方案，任何人都可以帮助我吗？

导致异常的文档：

{
"postsId":100,
"gmtCreate":"2015-08-17T16:38:54.000+08:00",
"gmtModified":"2015-12-10T19:38:17.000+08:00",
"status":1,
"postsType":1,
"title":"test",
"userId":123,
"userIconPath":"/user/avatar/123.png",
"province":null,
"city":null,
"district":null,
"recommendCover":null,
"location":{
    "lat":0,
    "lon":0
},
"lat":null,
"lng":null,
"forums":"[{"id":18,"name":"官方"}]",
"subForums":"[{"id":19,"name":"评测"}]",
"isDeleted":0,
"weight":0,
"dayGroup":"2015-08-17",
"content":"test"

}