Tested Env: Scala 2.11, lift-json_2.11-2.6.3
1. Normal Scala Map
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| val m = Map( | |
| "name" -> "john doe", | |
| "age" -> 18, | |
| "hasChild" -> true, | |
| "childs" -> List("a", "b", "c") | |
| ) |
m ‘s type: Map[String, Any]
2. Use lift-json’s implicit
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import net.liftweb.json.JsonAST._ | |
| import net.liftweb.json.JsonDSL._ | |
| import net.liftweb.json.Printer._ | |
| val m2: Map[String, JValue] = Map( | |
| "name" -> "john doe", | |
| "age" -> 18, | |
| "hasChild" -> true, | |
| "childs" -> List("a", "b", "c") | |
| ) |
Cast Map[String, Any] to Map[String, JValue] explicitly.
3. Convert Map[String, JValue] to JObject
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| val json = JObject(m2.toList.map(x => JField(x._1, x._2))) |
4. Generate String from JObject
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| // Compact | |
| compact(render(json)) | |
| // Pretty | |
| pretty(render(json)) |
5. But!
It cannot convert List that contains Map (List[Map]), since lift-json doesn’t have implicit function for converting Map to JValue. I have tried several implicit functions, but all of them failed.
So you need to traverse through List to convert Map to JValue (pre-processing), or explicitly convert values by calling implicit function directly with match expression.