Develop Reference

JSONObject start from last key to iterate over the all keys

I have this code block that iterates over the all keys in my JSONObject, jsonObject1 is a json object that has 1 key and bunch of json data as the value of this single key. So it look like this {"singleKey":"{"anotherKey":"anotherValue"}, {"someKey":"someValue"}"}
JSONObject jsonObject1 = new JSONObject(mystring);
Iterator<String> iter = jsonObject1.keys();
while(iter.hasNext())
{
String key = iter.next();
JSONObject jsonObject2 = new JSONObject(jsonObject1.getString(key));
key1 = jsonObject2.getString("key");
value1 = jsonObject2.getString("value");
String place += "\n" + key1 + ": " + value1;
}
What I want is, I want this while loop starts from the last key of the jsonObject2 and iterates over to the first key. So I will start adding to my place string starting from the last value of the jsonObject2. The first value of place string will be someKey: someValue (the last element of the JSONObject).
How can I start this iteration starting from the last key of the json object?

OK, try this (haven't fully tested):
public void jsonMethod(String mystring) throws JSONException {
JSONObject jsonObject1 = new JSONObject(mystring);
Iterator<String> iter = jsonObject1.keys();
ArrayList<String> keySet = new ArrayList<>();
while(iter.hasNext()){
keySet.add(iter.next());
}
Collections.reverse(keySet);
for(String myKey: keySet){
JSONObject jsonObject2 = new JSONObject(jsonObject1.getString(myKey));
// Do your existing stuff with jsonObject2
}
}

JSONObject from dot seperated strings

I am struggling with a specific problem, that I cannot think of correctly. The following is the problem
I have a map with key value like the following, i just used strings here
String key = "activate.message.success"
String value = "success"
String key1 = "activate.title"
String value1 = "Good Title"
String key2 = "activate.message.error"
String value2 = "error"
String key3 = "activate.message.short.poll"
String value3 = "This is short poll"
I need to build a json like the following
{
"activate":{
"message":{
"success":"success",
"error":"error",
"short":{
"poll":"This is short poll"
}
},
"title":"Good Title"
}
}
I could not think of a proper solution for this use case and struggling for 3 hours. I thought of using recursion, but i dont how exactly i could do. Please help with this. I am using java for this, I should use generic JSONObject to solve as there is not POJO mappings. So far I have just splitted the strings using separtor and stored in an another map like the following
public Map<String, Object> getJsonObjectFromKeyValueMap(Map<String, String> stringValueMap,
Map<String, Object> stringObjectMap) {
for (Entry entry : stringValueMap.entrySet()) {
String[] keyValueArrayString = entry.getKey().toString().split("\\.");
int sizeOfMap = keyValueArrayString.length;
int i = 0;
String concatString = "";
for (String processKey : keyValueArrayString) {
if (i < sizeOfMap - 1) {
concatString += processKey + ".";
stringObjectMap.put(concatString, (Object) new JSONObject());
} else {
concatString += processKey;
stringObjectMap.put(concatString, entry.getValue());
concatString = "";
}
i++;
}
}
return stringObjectMap;
}

First, let's update your data into a proper map :
Map<String, String> data = new HashMap<>();
data.put("activate.message.success", "success");
data.put("activate.title", "Good Title");
data.put("activate.message.error", "error");
data.put("activate.message.short.poll", "This is short poll");
Then, your logic is pretty close, for each node but the last, you create a new JSONObject, for the last, you insert the value.
If you try to build a JSONObject instead of the map directly, you would get a pretty good result already, well somewhat of a result.
The following will iterate a Map<String, String> of data.
For each entry, we split the key to getting the nodes.
Then, we just need to move in the json, if a node doesn't exist, we create it.
Then, for the last value, create the value.
public static JSONObject build(Map<String, String> data) {
JSONObject json = new JSONObject();
//Iterate the map entries
for (Entry<String, String> e : data.entrySet()) {
String[] keys = e.getKey().split("\\.");
// start from the root
JSONObject current = json;
for (int i = 0; i < keys.length; ++i) {
String key = keys[i];
//Search for the current node
try {
//If it exist, do nothing
current = current.getJSONObject(key);
} //If it does not exist
catch (JSONException ex) {
//Is it the last node, create the value
if (i == keys.length - 1) {
current.put(key, e.getValue());
} //Not the last node, create a new JSONObject
else {
JSONObject tmp = new JSONObject();
current.put(key, tmp);
current = tmp; //Always replace current with the last node to go deeped each iteration
}
}
}
}
return json;
}
And the example :
public static void main(String[] args) {
Map<String, String> data = new HashMap<>();
data.put("activate.message.success", "success");
data.put("activate.title", "Good Title");
data.put("activate.message.error", "error");
data.put("activate.message.short.poll", "This is short poll");
JSONObject json = build(data);
System.out.println(json.toString(4));
}
Ouptut:
{"activate": {
"message": {
"success": "success",
"short": {"poll": "This is short poll"},
"error": "error"
},
"title": "Good Title"
}}
Note : I used an exception to check for the existance of the key, if the map is huge, this could have some impact so you can simply use :
if(current.isNull(key)){
if (i == keys.length - 1) {
current.put(key, e.getValue());
} else {
JSONObject tmp = new JSONObject();
current.put(key, tmp);
current = tmp;
}
} else {
current = current.getJSONObject(key);
}
This was created using org.json/json

Parsing Json file and create Hashmap<k,v>

I am finding a solution for get each single key value of a JSONObject dynamicaly.
I have a JSON file like this:
{
"RESPONSE":{
"A":"test",
"B":{
"C":"0",
"D":"1"
},
"E":{
"F":"2",
"G":"3"
}
}
}
I wish to create a Hashmap that contains the key and the value of the objects, like this example:
legend:
key = value
"A" = "test"
"B" = "{"C":"0", "D":"1"}"
"B.C" = "0"
"B.D" = "1"
"E" = "{"F":"2","G":"3"}"
"E.F" = "2"
"E.G" = "3"
I have tried writing this code:
private static HashMap<String, Object> createJsonObjectsHashMapOfConfigFile(String jsonFilePath,
String JsonObjectToIterate) throws Exception {
HashMap<String, Object> jHashMap = new HashMap<>();
JSONObject jsonConfigFile = SimulatorUtil.readJsonFromFile(jsonFilePath); // Returns the Json file
JSONObject jsonConfigObj = jsonConfigFile.getJSONObject(JsonObjectToIterate); // JsonObjectToIterate -->
// "RESPONSE"
Iterator<?> configIter = jsonConfigObj.keys();
String currentDynamicKey = "";
while (configIter.hasNext()) {
currentDynamicKey = (String) configIter.next();
Object currentDynamicValue = jsonConfigObj.get(currentDynamicKey);
jHashMap.put(currentDynamicKey, currentDynamicValue);
logger.info(" ---> " + jHashMap.toString());
}
return jHashMap;
}
but it get only the first level key ("A", "B", "E").
I must use org.json.
Can anyone help me?
Thanks,
Luca

Get JSON keys with values

I have been trying to get the key and value of my JSONObject. I have no idea why this isn't working, because String key is clearly a string?
My code:
JSONObject obj = new JSONObject(historie2.getData());
Iterator<?> keys = obj.keys();
while(keys.hasNext()) {
String key = (String)keys.next();
String value = obj.getString(key); //This is where the error comes
}
The JSONObject:
{
"relatie_website": ["www.apple.com"],
"relatie_kvknummer": ["NL3234234"],
"relatie_naam": ["Apple international inc."],
"relatie_d400code": [null],
"relatie_zoeknaam": ["APPLE INC"],
"relatie_debiteurnummer": ["3523523"],
"relatie_btwnummer": ["332342"]
}
This is the error I have been getting:
org.json.JSONException: JSONObject["relatie_website"] not a string.

You should change your object to be sth like that :
{
"relatie_website": "www.apple.com",
"relatie_kvknummer": "NL3234234",
"relatie_naam": "Apple international inc.",
"relatie_d400code": null,
"relatie_zoeknaam": "APPLE INC",
"relatie_debiteurnummer": "3523523",
"relatie_btwnummer": "332342"
}
Because the problem is that your values are an array and not a string.
But if you need te keep your values in an array you can change your code to support the arrays :
JSONObject obj = new JSONObject(historie2.getData());
Iterator<?> keys = obj.keys();
while(keys.hasNext()) {
String key = (String)keys.next();
JSONArray value = obj.getJSONArray(key);
}
And you will have a JsonArray that you can manipulate as you want by doing sth like that :
for (int i = 0; i < value.length(); i++) {
String val = value.getString(i).toString();
logger.info("val : " + val);
}

Parse a JSON-string in Android

Right now I have the following JSON string:
"{"1":{"from":"540","to":"1020"},"2":{"from":"540","to":"1020"},"3":{"from":"540","to":"1020"},"4":{"from":"540","to":"1020"},"5":{"from":"540","to":"1020"},"6":{"from":"540","to":"1020"},"7":{"from":"540","to":"1020"}}"
and I want to parse it in Android Studio and iterate all just for this kind of result:
String day = monday;
int hourstart = from;
int hoursclose = to;
of course from and to means numbers. Does anyone know how construction of a JSON parser should look like?

Try this:
//here jsonString is your json in string format
JSONObject obj3=new JSONObject(jsonString);
JSONObject obj4=null;
//Getting all the keys inside json object with keys- from and to
Iterator<String> keys= obj3.keys();
while (keys.hasNext())
{
String keyValue = (String)keys.next();
obj4 = obj3.getJSONObject(keyValue);
//getting string values with keys- from and to
String from = obj4.getString("from");
String to = obj4.getString("to");
int hourstart = Integer.parseInt(from);
int hoursclose = Integer.parseInt(to);
System.out.println("From : "+ hourstart +" To : "+ hoursclose);
}