I'm using JsonReader and JsonValue like below:
JsonReader json = new JsonReader();
JsonValue jsonValue = json.parse(Gdx.files.internal("file.json"));
My question is How to add a new item to jsonValue or update values?
I found the solution:
jsonValue.remove("name");
jsonValue.addChild("name", new JsonValue("new Value"));
Related
I am trying to iterate through a value (that is a hashMap) of a JSONObject.
First I get a server response that is a String.
Then I turn it into a String! like this:
val responseString = response.serverResponse
Then I turn it into a JSONObject like this:
val jsonObj = JSONObject(responseString.toString()).get("data")
I do the second step because I only want to keep the LinkedHashMap shown in the picture attached.
But the second step returns type "Any" and then I cant iterate through the LinkedHashMap
JSONObject myjsonObject = new JSONObject();
Iterator keyvalues = jsonObject.keys();
while(keys.hasNext()) {String key = keyvalues.next();
if (myjsonObject.get(key) instanceof myjsonObject) {
}
}
var jsonElements = List[String]()
val params = Map("host"->host)
for((key,value)<-mapSql){
val map = Map("metric"->key,"timestamp"->new Date().getTime,"value"->value,"tags"->params)
jsonElements=JsonUtility.toJSONString(map) :: jsonElements
}
val entity = new StringEntity(JsonUtility.toJSONString(jsonElements))
println("json elements final list is "+jsonElements)
println("json elements final JSON Obj is "+JsonUtility.toJSONString(jsonElements))
entity.setContentType(new BasicHeader("Content-Type", "application/json"))
val postRequest: HttpPost = new HttpPost(putURL)
postRequest.setEntity(entity)
val postResponse: CloseableHttpResponse = httpclient.execute(postRequest)
I basically need to add values to a list and then send them together in a JSON Array.
However this is introducing unnecessary escape characters "/" in the output which is rendering the post request useless and I am getting an error to the API hit. the following is the response :
json elements final list is List({"metric":"replicationLag","timestamp":1410179907871,"value":0.0,"tags":{"host":"tg-em-db01.nm.xxxx.com"}}, {"metric":"status","timestamp":1410179907824,"value":1,"tags":{"host":"tg-em-db01.nm.xxxxx.com"}})
json elements final JSON Obj is ["{\"metric\":\"replicationLag\",\"timestamp\":1410179907871,\"value\":0.0,\"tags\":{\"host\":\"tg-em-db01.nm.xxxx.com\"}}","{\"metric\":\"status\",\"timestamp\":1410179907824,\"value\":1,\"tags\":{\"host\":\"tg-em-db01.nm.xxxxx.com\"}}"]
I can replace and remove all the escape characters by the replaceAll function but I do not want to do that. is there a better way to append objects to an already existing JSON object and then change it to an array ( which i can easily do by new JsonArray(List(JsonObj)) ) so that i dont get any escape characters anywhere.
Something like this :
val params = Map("host"->host)
var map = Map[String,Any]()
for((key,value)<-mapSql){
map ++= Map("metric"->key,"timestamp"->new Date().getTime,"value"->value,"tags"->params)
}
val entity = new StringEntity(JsonUtility.toJSONString(List(map)))
println("json elements final list is "+map)
println("json elements final JSON Obj is "+JsonUtility.toJSONString(List(map)))
is giving me this as an ouput :
json elements final list is Map(metric -> replicationLag, timestamp -> 1410180939983, value -> 0.0, tags -> Map(host -> tg-em-db01.nm.xxxx.com))
json elements final JSON Obj is [{"metric":"replicationLag","timestamp":1410180939983,"value":0.0,"tags":{"host":"tg-em-db01.nm.xxxxx.com"}}]
But I need something like this :
[ {"metric":blah blah} , {"metric":blah blah} ]
Is there a way to append to maps such that the same key values are not clubbed ?
Thanks in advancE!
var jsonElements = List[Map[String, Any]]()
val params = Map("host" -> host)
for ((key, value) <- mapSql) {
val map = Map("metric" -> key, "timestamp" -> new Date().getTime, "value" -> value, "tags" -> params)
jsonElements = map :: jsonElements
}
val entity = new StringEntity(JsonUtility.toJSONString(jsonElements))
entity.setContentType(new BasicHeader("Content-Type", "application/json"))
val postRequest: HttpPost = new HttpPost(putURL)
postRequest.setEntity(entity)
val postResponse: CloseableHttpResponse = httpclient.execute(postRequest)
object JsonUtility {
def toJSONString(obj:Any):String = {
compact(JsonAST.render(decompose(obj)))
}
}
I have written jsp code for generating json .But its not generating exact JsonArray. Its like
[{"item":"747"},,{"item":"1617"},]
instead of
[{"item":"747"},{"item":"1617"}].
below is the code
JSONObject obj = new JSONObject();
JSONArray ja = new JSONArray();
obj.put("item", "747");
ja.put(obj);
obj = new JSONObject();
obj.put("item", "1617");
ja.put(obj);
out.println(ja);
I have tested your code by using json-simple-1.1.1.jar, worked fine there is no extra , came in output. while testing your code eclipse given one error message like put() method is undefined for the type JSONArray, so i replaced put with add like:
JSONObject obj = new JSONObject();
JSONArray ja = new JSONArray();
obj.put("item", "747");
ja.add(obj);
obj = new JSONObject();
obj.put("item", "1617");
ja.add(obj);
out.println(ja);
Also see Gson
Is it possible to add new field to JsObject?
val jsonObj = Json.obj()
jsonObj.put("field" -> 100) <==== Somthing like this
I have a lot of methods that add new fields. How can I dynamically create JsObject?
Yes, you can add a new field using the "+" method. Note that the object is immutable, so this will create a new copy of the JsObject with the added field:
val obj = Json.obj()
// obj - {}
val newObj = obj + ("name" -> JsString("Kip"))
// newObj - {"name":"Kip"}
I'm converting a list of Foo objects to a JSON string. I need to parse the JSON string back into a list of Foos. However in the following example, parsing gives me a list of JSONObjects instead of Foos.
Example
List list = [new Foo("first"), new Foo("second")]
def jsonString = (list as JSON).toString()
List parsedList = JSON.parse(jsonString) as List
println parsedList[0].getClass() // org.codehaus.groovy.grails.web.json.JSONObject
How can I parse it into Foos instead?
Thanks in advance.
I had a look at the API docs for JSON and there doesn't appear to be any way to parse to a JSON string to a specific type of object.
So you'll just have to write the code yourself to convert each JSONObject to a Foo. Something like this should work:
import grails.converters.JSON
import org.codehaus.groovy.grails.web.json.*
class Foo {
def name
Foo(name) {
this.name = name
}
String toString() {
name
}
}
List list = [new Foo("first"), new Foo("second")]
def jsonString = (list as JSON).toString()
List parsedList = JSON.parse(jsonString)
// Convert from a list of JSONObject to a list of Foo
def foos = parsedList.collect {JSONObject jsonObject ->
new Foo(name: jsonObject.get("name"))
}
A more general solution would be to add a new static parse method such as the following to the JSON metaClass, that tries to parse the JSON string to a List of objects of a particular type:
import grails.converters.JSON
import org.codehaus.groovy.grails.web.json.*
class Foo {
def name
Foo(name) {
this.name = name
}
String toString() {
name
}
}
List list = [new Foo("first"), new Foo("second")]
def jsonString = (list as JSON).toString()
List parsedList = JSON.parse(jsonString)
// Define the new method
JSON.metaClass.static.parse = {String json, Class clazz ->
List jsonObjs = JSON.parse(json)
jsonObjs.collect {JSONObject jsonObj ->
// If the user hasn't provided a targetClass read the 'class' proprerty in the JSON to figure out which type to convert to
def targetClass = clazz ?: jsonObj.get('class') as Class
def targetInstance = targetClass.newInstance()
// Set the properties of targetInstance
jsonObj.entrySet().each {entry ->
if (entry.key != "class") {
targetInstance."$entry.key" = entry.value
}
}
targetInstance
}
}
// Try the new parse method
List<Foo> foos = JSON.parse(jsonString, Foo)
// Confirm it worked
assert foos.every {Foo foo -> foo.class == Foo && foo.name in ['first', 'second'] }
You can try out the code above in the groovy console. A few warnings
I have only performed very limited testing on the code above
There are two JSON classes in the latest Grails release, I'm assuming you're using the one that is not deprecated
If you are doing this in a Grails controller, and Foo IS indeed a domain object, don't forget that armed with your JSON map, you can also do:
List list = [new Foo("first"), new Foo("second")]
def jsonString = (list as JSON).toString()
List parsedList = JSON.parse(jsonString) as List
Foo foo = new Foo()
bindData(foo, parsedList[0]);
I've taken this code and extended it to work with nested structures. It relies on a 'class' attribute existing in the JSON. If there's a better way by now in Grails please let me know.
// The default JSON parser just creates generic JSON objects. If there are nested
// JSON arrays they are not converted to theirs types but are left as JSON objects
// This converts nested JSON structures into their types.
// IT RELIES ON A PROPERTY 'class' that must exist in the JSON tags
JSON.metaClass.static.parseJSONToTyped = {def jsonObjects ->
def typedObjects = jsonObjects.collect {JSONObject jsonObject ->
if(!jsonObject.has("class")){
throw new Exception("JSON parsing failed due to the 'class' attribute missing: " + jsonObject)
}
def targetClass = grailsApplication.classLoader.loadClass(jsonObject.get("class"))
def targetInstance = targetClass.newInstance()
// Set the properties of targetInstance
jsonObject.entrySet().each {entry ->
// If the entry is an array then recurse
if(entry.value instanceof org.codehaus.groovy.grails.web.json.JSONArray){
def typedSubObjects = parseJSONToTyped(entry.value)
targetInstance."$entry.key" = typedSubObjects
}
else if (entry.key != "class") {
targetInstance."$entry.key" = entry.value
}
}
targetInstance
}
return typedObjects
}
As of Grails 2.5, this is possible:
Period test = new Period()
test.periodText = 'test'
String j = test as JSON
def p = JSON.parse(j)
test = p.asType(Period)
println(test.periodText)
Output:
test
I am unsure of when it became an option.