Question

I am trying to merge together multiple JObjects to become one single JObject. I have a list of JObjects that I am trying to iterate over and merge each of them into one object, essentially creating one large json object.

The below works fine, however when in a list it doesn't work. I know im doing something wrong but not sure what?

val obj1: JObject = RancherHelper.convertToJObject(containers.head)
val obj2: JObject = RancherHelper.convertToJObject(containers(1))
val obj3: JObject = RancherHelper.convertToJObject(containers(2))

val x: JObject = obj1 merge obj2 merge obj3

This doesn't work:

def mergeJObjects(containers: List[JObject]): JObject = {
    val fullJsonObject: JObject = JObject()
    val singleObject = for{
      container <- containers
      fullObj = fullJsonObject.merge(container)
    } yield fullObj

    fullJsonObject
}

Answer 1

将其折叠，而不是在列表上进行映射：

site.com/myapp

您上面所写的是语法糖：

def mergeJObjects(containers: List[JObject]): JObject = {
  containers.foldLeft(JObject())((merged, next) => merged.merge(next))
}

基本上，您正在容器列表上进行映射，并且将每个容器与一个空JSON对象（val fullJsonObject = JObject() val singleObject = containers.map { container => val fullObj = fullJsonObject.merge(container) fullObj } fullJsonObject）合并。因此，fullJsonObject与singleObject没有什么不同；它是您原始JSON对象的列表。而且，由于containers是一个不可变空的fullJsonObject，因此您只需在方法末尾返回空的JSON对象。

Merging multiple JObjects in a list - Json4s

1 个答案: