How to modify values of JsonObject
问题
https://stackoverflow.com/questions/66955052/how-to-modify-values-of-jsonobject
I want to add a new field to jsonObject and this new field's name will be based on a value of another field. To be clear, this an examples of what I want to achieve.
{
"values": [
{
"id": "1",
"properties": [
{
"stat": "memory",
"data": 8
},
{
"stat": "cpu",
"data": 4
}
]
},
{
"id": "2",
"properties": [
{
"stat": "status",
"data": "OK"
},
{
"stat": "cpu",
"data": 4
}
]
}
]
}
I want to add a new field to each json object that will have the value of field "stat" as name.
{
"values": [
{
"id": "1",
"properties": [
{
"stat": "memory",
"data": 8,
"memory": 8
},
{
"stat": "cpu",
"data": 4,
"cpu": 4
}
]
},
{
"id": "2",
"properties": [
{
"stat": "status",
"data": 0,
"status": 0
},
{
"stat": "cpu",
"data": 4,
"cpu": 4
}
]
}
]
}
I have tried to do the following with JsonPath library but for me it's an ugly solution as I will parse the json three times and I do some manual replacements.
val configuration = Configuration.builder().options(Option.DEFAULT_PATH_LEAF_TO_NULL, Option.ALWAYS_RETURN_LIST).build()
val jsonContext5 = JsonPath.using(configuration).parse(jsonStr)
val listData = jsonContext.read("$['values'][*]['properties'][*]['data']").toString
.replace("[", "").replace("]","").split(",").toList
val listStat = jsonContext.read("$['values'][*]['properties'][*]['stat']").toString
.replace("[", "").replace("]","")
.replace("\"","").split(",").toList
// Replacing values of "stat" by values of "data"
jsonContext5.map("$['values'][*]['properties'][*]['stat']", new MapFunction() {
var count = - 1
override def map(currentValue: Any, configuration: Configuration): AnyRef = {
count += 1
listData(count)
}
})
// replace field stat by its value
for(count <- 0 to listStat.size - 1){
val path = s"['values'][*]['properties'][$count]"
jsonContext5.renameKey(path, "stat", s"${listStat(count)}")
}
This is the result obtained
{
"values": [
{
"id": "1",
"properties": [
{
"data": 8,
"memory": "8"
},
{
"data": 4,
"cpu": "4"
}
]
},
{
"id": "2",
"properties": [
{
"data": 0,
"memory": "0"
},
{
"data": 4,
"cpu": "4"
}
]
}
]
}
Is there any better method to achieve this result ? I tried to do it with gson but it's not good handling paths.
This a way to do it with Gson but I will lose the information about other columns since I'm creating another json.
val jsonArray = jsonObject.get("properties").getAsJsonArray
val iter = jsonArray.iterator()
val agreedJson = new JsonArray()
while(iter.hasNext) {
val json = iter.next().getAsJsonObject
agreedJson.add(replaceCols(json))
}
def replaceCols(json: JsonObject) = {
val fieldName = "stat"
if(json.has(fieldName)) {
val columnName = json.get(fieldName).getAsString
val value: String = if (json.has("data")) json.get("data").getAsString else ""
json.addProperty(columnName, value)
}
json
}
解答
为json的每个properties中的每条记录添加新字段，当前stat作为字段名，data作为字段值。用Java 实现代码较长。
用Java 下的开源包 SPL 很容易写，只要 1 句：
A |
|
1 |
=json(json(file("data.json").read()).values.run(properties=properties.(([["stat","data"]|stat]|[~.array()|data]).record()))) |
SPL 提供了 JDBC 供 Java 调用，把上面的脚本存为 addfield.splx，在 Java 中以存储过程的方式调用脚本文件：
…
Class.forName("com.esproc.jdbc.InternalDriver");
con= DriverManager.getConnection("jdbc:esproc:local://");
st = con.prepareCall("call addfield()");
st.execute();
…
English version