在以下的 json 中，我需要得到的几个字段是：当 set.class.0 非空的时候，返回该 set 列表中的某些字段
{
"code": 0,
"msg": null,
"data": {
"set": [
{
"id": "1566", "type": 1,
"class": { "0": [],"1": [ "460"],"2": ["460","460","461" ] },
},
{
"id": "1788", "type": 1,
"class": { "0": [ "461" ], "1": [], "2": [ "460" ]},
},
{
"id": "1762","type": 1,
"class": { "0": [],"1": [ "461" ], "2": [ "460" ],
},
{
"id": "1790","type": 1,
"class": { "0": [ "460","461"], "1": [], "2": [] },
},
{
"id": "1792","type": 2,
"class": {"0": [ "460", "461"], "1": [],"2": []
},
},]
}}
既是当存在"0": [ "461" ] 与"0": [ "460", "461"] 等” 0“为非空内容时，取 set[0] 中的 id,type 与” 0"的属性值，在此例子中，则是得到 id=1788,type=1,"0"=461。我用 jsonpath 仅仅是实现了当 set.class.0 非空的时候，返回整个 set:
List<Object> list=JsonPath.read(string, "$.data.set[?(@.class.0.length()>0]");
得到的结果是
{
"id": "1788", "type": 1,
"class": { "0": [ "461" ], "1": [], "2": [ "460" ]},
},
{
"id": "1790","type": 1,
"class": { "0": [ "460","461"], "1": [], "2": [] },
},
{
"id": "1792","type": 2,
"class": {"0": [ "460", "461"], "1": [],"2": []},
}