Scala example source code file (json.scala)

This example Scala source code file (json.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

any, any, john, jsonarray, jsonobject, jsonobject, list, map, map, passed, smith, string, string, york

The Scala json.scala source code

import scala.util.parsing.json._
import scala.collection.immutable.TreeMap

object Test extends App {
  /* This method converts parsed JSON back into real JSON notation with objects in
   * sorted-key order. Not required by the spec, but it allows us to to a stable
   * toString comparison. */
  def jsonToString(in : Any) : String = in match {
    case l : List[_] => "[" + l.map(jsonToString).mkString(", ") + "]"
    case m : Map[String,_] => "{" + m.elements.toList
         .sort({ (x,y) => x._1 < y._1 })
         .map({ case (k,v) => "\"" + k + "\": " + jsonToString(v) })
         .mkString(", ") + "}"
    case s : String => "\"" + s + "\""
    case x => x.toString
  }

  /*
   * This method takes input JSON values and sorts keys on objects.
   */
  def sortJSON(in : Any) : Any = in match {
    case l : List[_] => l.map(sortJSON)
    case m : Map[String,_] => TreeMap(m.mapElements(sortJSON).elements.toSeq : _*)
    // For the object versions, sort their contents, ugly casts and all...
    case JSONObject(data) => JSONObject(sortJSON(data).asInstanceOf[Map[String,Any]])
    case JSONArray(data) => JSONArray(sortJSON(data).asInstanceOf[List[Any]])
    case x => x
  }

  // For this one, just parsing should be considered a pass
  def printJSON(given : String) {
    JSON parseRaw given match {
      case None => println("Parse failed for \"%s\"".format(given))
      case Some(parsed) => println("Passed parse  : " + sortJSON(parsed))
    }
  }
   
  // For this usage, do a raw parse (to JSONObject/JSONArray)
  def printJSON(given : String, expected : JSONType) {
    printJSON(given, JSON.parseRaw, expected)
  }

  // For this usage, do a raw parse (to JSONType and subclasses)
  def printJSONFull(given : String, expected : Any) {
    printJSON(given, JSON.parseFull, expected)
  }

  // For this usage, do configurable parsing so that you can do raw if desired
  def printJSON[T](given : String, parser : String => T, expected : Any) {
    parser(given) match {
      case None => println("Parse failed for \"%s\"".format(given))
      case Some(parsed) => if (parsed == expected) {
        println("Passed compare: " + parsed)
      } else {
        val eStr = sortJSON(expected).toString
        val pStr = sortJSON(parsed).toString
        stringDiff(eStr,pStr)
      }
    }
  }

  def stringDiff (expected : String, actual : String) {
    if (expected != actual) {
      // Figure out where the Strings differ and generate a marker
        val mismatchPosition = expected.toList.zip(actual.toList).findIndexOf({case (x,y) => x != y}) match {
          case -1 => Math.min(expected.length, actual.length)
          case x => x
        }
        val reason = (" " * mismatchPosition) + "^"
        println("Expected: %s\nGot     : %s \n          %s".format(expected, actual, reason))

    } else {
      println("Passed compare: " + actual)
    }
  }


  // The library should differentiate between lower case "l" and number "1" (ticket #136)
  printJSON("{\"name\" : \"value\"}", JSONObject(Map("name" -> "value")))
  printJSON("{\"name\" : \"va1ue\"}", JSONObject(Map("name" -> "va1ue")))
  printJSON("{\"name\" : { \"name1\" : \"va1ue1\", \"name2\" : \"va1ue2\" } }",
            JSONObject(Map("name" -> JSONObject(Map("name1" -> "va1ue1", "name2" -> "va1ue2")))))

  // Unicode escapes should be handled properly
  printJSON("{\"name\" : \"\\u0022\"}")

  // The library should return a map for JSON objects (ticket #873)
  printJSONFull("{\"function\" : \"add_symbol\"}", Map("function" -> "add_symbol"))

  // The library should recurse into arrays to find objects (ticket #2207)
  printJSON("[{\"a\" : \"team\"},{\"b\" : 52}]", JSONArray(List(JSONObject(Map("a" -> "team")), JSONObject(Map("b" -> 52.0)))))
  
  // The library should differentiate between empty maps and lists (ticket #3284)
  printJSONFull("{}", Map()) 
  printJSONFull("[]", List())
  
  // Lists should be returned in the same order as specified
  printJSON("[4,1,3,2,6,5,8,7]", JSONArray(List[Double](4,1,3,2,6,5,8,7)))

  // Additional tests
  printJSON("{\"age\": 0}")

  // The library should do a proper toString representation using default and custom renderers (ticket #3605)
  stringDiff("{\"name\" : \"va1ue\"}", JSONObject(Map("name" -> "va1ue")).toString)
  stringDiff("{\"name\" : {\"name1\" : \"va1ue1\", \"name2\" : \"va1ue2\"}}",
             JSONObject(Map("name" -> JSONObject(TreeMap("name1" -> "va1ue1", "name2" -> "va1ue2")))).toString)

  stringDiff("[4.0, 1.0, 3.0, 2.0, 6.0, 5.0, 8.0, 7.0]", JSONArray(List[Double](4,1,3,2,6,5,8,7)).toString)

  // A test method that escapes all characters in strings
  def escapeEverything (in : Any) : String = in match {
    case s : String => "\"" + s.map(c => "\\u%04x".format(c : Int)).mkString + "\""
    case jo : JSONObject => jo.toString(escapeEverything)
    case ja : JSONArray => ja.toString(escapeEverything)
    case other => other.toString
  }

  stringDiff("{\"\\u006e\\u0061\\u006d\\u0065\" : \"\\u0076\\u0061\\u006c\"}", JSONObject(Map("name" -> "val")).toString(escapeEverything))

  println

  // from http://en.wikipedia.org/wiki/JSON
  val sample1 = """
{
    "firstName": "John",
    "lastName": "Smith",
    "address": {
        "streetAddress": "21 2nd Street",
        "city": "New York",
        "state": "NY",
        "postalCode": 10021
    },
    "phoneNumbers": [
        "212 732-1234",
        "646 123-4567"
    ]
}"""

  // Should be equivalent to:
  val sample1Obj = Map(
    "firstName" -> "John",
    "lastName" -> "Smith",
    "address" -> Map(
      "streetAddress" -> "21 2nd Street",
      "city" -> "New York",
      "state" -> "NY",
      "postalCode" -> 10021
    ),
    "phoneNumbers"-> List(
        "212 732-1234",
        "646 123-4567"
    )
  )

  
  printJSONFull(sample1, sample1Obj)
  println

  // from http://www.developer.com/lang/jscript/article.php/3596836
  val sample2 = """
{
   "fullname": "Sean Kelly",
   "org": "SK Consulting",
   "emailaddrs": [
      {"type": "work", "value": "kelly@seankelly.biz"},
      {"type": "home", "pref": 1, "value": "kelly@seankelly.tv"}
   ],
    "telephones": [
      {"type": "work", "pref": 1, "value": "+1 214 555 1212"},
      {"type": "fax", "value": "+1 214 555 1213"},
      {"type": "mobile", "value": "+1 214 555 1214"}
   ],
   "addresses": [
      {"type": "work", "format": "us",
       "value": "1234 Main StnSpringfield, TX 78080-1216"},
      {"type": "home", "format": "us",
       "value": "5678 Main StnSpringfield, TX 78080-1316"}
   ],
    "urls": [
      {"type": "work", "value": "http://seankelly.biz/"},
      {"type": "home", "value": "http://seankelly.tv/"}
   ]
}"""

  printJSON(sample2)
  println

  // from http://json.org/example.html
  val sample3 = """
{"web-app": {
  "servlet": [   
    {
      "servlet-name": "cofaxCDS",
      "servlet-class": "org.cofax.cds.CDSServlet",
      "init-param": {
        "configGlossary:installationAt": "Philadelphia, PA",
        "configGlossary:adminEmail": "ksm@pobox.com",
        "configGlossary:poweredBy": "Cofax",
        "configGlossary:poweredByIcon": "/images/cofax.gif",
        "configGlossary:staticPath": "/content/static",
        "templateProcessorClass": "org.cofax.WysiwygTemplate",
        "templateLoaderClass": "org.cofax.FilesTemplateLoader",
        "templatePath": "templates",
        "templateOverridePath": "",
        "defaultListTemplate": "listTemplate.htm",
        "defaultFileTemplate": "articleTemplate.htm",
        "useJSP": false,
        "jspListTemplate": "listTemplate.jsp",
        "jspFileTemplate": "articleTemplate.jsp",
        "cachePackageTagsTrack": 200,
        "cachePackageTagsStore": 200,
        "cachePackageTagsRefresh": 60,
        "cacheTemplatesTrack": 100,
        "cacheTemplatesStore": 50,
        "cacheTemplatesRefresh": 15,
        "cachePagesTrack": 200,
        "cachePagesStore": 100,
        "cachePagesRefresh": 10,
        "cachePagesDirtyRead": 10,
        "searchEngineListTemplate": "forSearchEnginesList.htm",
        "searchEngineFileTemplate": "forSearchEngines.htm",
        "searchEngineRobotsDb": "WEB-INF/robots.db",
        "useDataStore": true,
        "dataStoreClass": "org.cofax.SqlDataStore",
        "redirectionClass": "org.cofax.SqlRedirection",
        "dataStoreName": "cofax",
        "dataStoreDriver": "com.microsoft.jdbc.sqlserver.SQLServerDriver",
        "dataStoreUrl": "jdbc:microsoft:sqlserver://LOCALHOST:1433;DatabaseName=goon",
        "dataStoreUser": "sa",
        "dataStorePassword": "dataStoreTestQuery",
        "dataStoreTestQuery": "SET NOCOUNT ON;select test='test';",
        "dataStoreLogFile": "/usr/local/tomcat/logs/datastore.log",
        "dataStoreInitConns": 10,
        "dataStoreMaxConns": 100,
        "dataStoreConnUsageLimit": 100,
        "dataStoreLogLevel": "debug",
        "maxUrlLength": 500}},
    {
      "servlet-name": "cofaxEmail",
      "servlet-class": "org.cofax.cds.EmailServlet",
      "init-param": {
      "mailHost": "mail1",
      "mailHostOverride": "mail2"}},
    {
      "servlet-name": "cofaxAdmin",
      "servlet-class": "org.cofax.cds.AdminServlet"},
 
    {
      "servlet-name": "fileServlet",
      "servlet-class": "org.cofax.cds.FileServlet"},
    {
      "servlet-name": "cofaxTools",
      "servlet-class": "org.cofax.cms.CofaxToolsServlet",
      "init-param": {
        "templatePath": "toolstemplates/",
        "log": 1,
        "logLocation": "/usr/local/tomcat/logs/CofaxTools.log",
        "logMaxSize": "",
        "dataLog": 1,
        "dataLogLocation": "/usr/local/tomcat/logs/dataLog.log",
        "dataLogMaxSize": "",
        "removePageCache": "/content/admin/remove?cache=pages&id=",
        "removeTemplateCache": "/content/admin/remove?cache=templates&id=",
        "fileTransferFolder": "/usr/local/tomcat/webapps/content/fileTransferFolder",
        "lookInContext": 1,
        "adminGroupID": 4,
        "betaServer": true}}],
  "servlet-mapping": {
    "cofaxCDS": "/",
    "cofaxEmail": "/cofaxutil/aemail/*",
    "cofaxAdmin": "/admin/*",
    "fileServlet": "/static/*",
    "cofaxTools": "/tools/*"},
 
  "taglib": {
    "taglib-uri": "cofax.tld",
    "taglib-location": "/WEB-INF/tlds/cofax.tld"}
  }
}"""

  printJSON(sample3)
  println
}