Filter和term使用，为啥查询文本就查询不到结果

{
    "query":{
        "bool":{
            "filter":{
                "term":{
                    "author":"李史峰"
                }
            }
        }
    }
}

返回结果：

{
    "took":2,
    "timed_out":false,
    "_shards":{
        "total":3,
        "successful":3,
        "skipped":0,
        "failed":0
    },
    "hits":{
        "total":0,
        "max_score":null,
        "hits":[

        ]
    }
}