如何使用Scala删除重复的键并合并列表的其他键值? [英] How to remove duplicate keys and merge other key-values of list using scala?

问题描述

我正在遵循List [JSONObject]结构作为某些代码片段的输出-

I am getting following List[JSONObject] structure as a output of some snippet-

List(List({
"groupName": "group1",
"maxSeverity": -1,
"hostCount": 3,
"members": [
    "192.168.20.11",
    "192.168.20.52",
    "192.168.20.53"
]
}),
List(),
List({
"groupName": "group1",
"maxSeverity": -1,
"hostCount": 2,
"members": [
    "192.168.20.20",
    "192.168.20.52"
]
}))

我想合并整个输出以形成一个包含以下内容的列表: 1)组名

I want to merge whole output to form a list which contains - 1) group name

2)严重性-所有列表元素中的严重性最低

2) severity - which will be minimum from all list elements

3)hostcout-从所有列表元素中添加主机计数

3) hostcout - addition of hostcount from all list elements

4)成员-相似的数组，所有列表元素中没有重复值.

4) members - similar array without duplicate values from all list elements.

所以输出将有点像这样-

So output will be somewhat like this-

List({
"groupName": "group1",
"maxSeverity": -1,
"hostCount": 5,
"members": [
    "192.168.20.11",
    "192.168.20.52",
    "192.168.20.53",
    "192.168.20.20",
    "192.168.20.52"
]
})

如何将整个列表合并为一个列表以获得上述输出?

How do I merge whole list to a single list to get above mentioned output???

推荐答案

请考虑使用Jackson将其解析为case类，然后以这种方式使用数据.

Consider using Jackson to parse these into a case class, and then work with the data that way.

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

  case class ServerGroup(groupName: String, hostCount: Int, maxSeverity: Int, members: Iterable[String])

  def collapseGroup(groups: List[ServerGroup]): ServerGroup = {
    val members = groups.flatMap(_.members).toSet
    ServerGroup(groups.head.groupName, members.size, groups.map(_.maxSeverity).min, members)
  }

  def main(args: Array[String]) {
    val objectMapper = new ObjectMapper with ScalaObjectMapper
    objectMapper.registerModule(DefaultScalaModule)

    val allGroups = objectMapper.readValue[List[ServerGroup]](rawData)
    val output = allGroups.groupBy(_.groupName).values.map(collapseGroup)
    objectMapper.writerWithDefaultPrettyPrinter().writeValue(System.out, output)
  }

  val rawData = """
[{
  "groupName": "group1",
  "hostCount": 3,
  "maxSeverity": -1,
  "members": [
    "192.168.20.11",
    "192.168.20.52",
    "192.168.20.53"
  ]
},{
  "groupName": "group1",
  "hostCount": 2,
  "maxSeverity": -1,
  "members": [
    "192.168.20.20",
    "192.168.20.52"
  ]
},{
  "groupName": "group2",
  "hostCount": 1,
  "maxSeverity": 2,
  "members": [
    "192.168.20.52"
  ]
}]"""

}

具有以下输出:

[ {
  "groupName" : "group2",
  "hostCount" : 1,
  "maxSeverity" : 2,
  "members" : [ "192.168.20.52" ]
}, {
  "groupName" : "group1",
  "hostCount" : 4,
  "maxSeverity" : -1,
  "members" : [ "192.168.20.11", "192.168.20.52", "192.168.20.53", "192.168.20.20" ]
} ]

这篇关于如何使用Scala删除重复的键并合并列表的其他键值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！