Question

我有一个像这样的json：

[
    {
        "firstName":"Pierre",
        "age":"20",
        "timestamp": "123"
    },
    {
        "firstName":"Jack",
        "age":"20",
        "timestamp": "123"
    },  
    {
        "firstName":"Olive",
        "age":"20",
        "timestamp": "123"
    },  
    {
        "firstName":"Tom",
        "age":"20",
        "timestamp": "123"
    }
]

我想将所有属性timestamp更新为456.然后我创建一个这样的代码：

   import org.json.simple.{JSONArray, JSONObject}

   myJsonArray.forEach {
      obj =>
        val jsonObject = obj.asInstanceOf[JSONObject]
        val jsonMap = jsonObject.asInstanceOf[java.util.HashMap[String,Any]]
        jsonMap.put("timestamp",456)

    }

但我参与编译：

Error:(31, 7) missing parameter type
      obj =>

你知道吗？还是其他任何实施？

Answer 1

您的JSON已损坏，"age":"20"字段后应该有一个逗号。因此，在更正它之后，您可以使用以下内容来更新您的JSON。在这里，我使用了jackson liberary进行JSON解析。

import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.module.scala.DefaultScalaModule
import com.fasterxml.jackson.module.scala.experimental.ScalaObjectMapper

val objectMapper = new ObjectMapper() with ScalaObjectMapper
objectMapper.registerModule(DefaultScalaModule)
val str = "[{\"firstName\":\"Pierre\",\"age\":\"20\",\"timestamp\":\"123\"},{\"firstName\":\"Jack\",\"age\":\"20\",\"timestamp\":\"123\"},{\"firstName\":\"Olive\",\"age\":\"20\",\"timestamp\":\"123\"},{\"firstName\":\"Tom\",\"age\":\"20\",\"timestamp\":\"123\"}]"
//convert JSON string to Map(String,String) 
val jsonMap = objectMapper.readValue(str, classOf[Array[Map[String, String]]])
//Overwrite the key time-stamp in the given Map
val changedMap = jsonMap.map(_ ++ Map("timestamp" -> "466"))
//Convert the Map again to string
val jsonString = objectMapper.writeValueAsString(changedMap)

println(jsonString)
//output
//[{"firstName":"Pierre","age":"20","timestamp":"466"},{"firstName":"Jack","age":"20","timestamp":"466"},{"firstName":"Olive","age":"20","timestamp":"466"},{"firstName":"Tom","age":"20","timestamp":"466"}]

如何从jsonArray中放入/更新所有json属性

1 个答案: