How do I parse JSON into an int

Question

I have Parsed some JSON data and its working fine as long as I store it in String variables   My problem is that I need the ID in an int varibable and not in String  i have tried to make a cast int id    int  jsonObj get       But it gives an error message that I cannot convert an object to an int  So I tried to convert by using      String id    String  jsonObj get  id    int value   Integer parseInt id     But also that is not working  What is wrong  How is JSON working with int  My strings are working just fine its only when I try to make them as an int I get problems   Here is my code    public void parseJsonData   throws ParseException            JSONParser parser   new JSONParser            Object obj   parser parse jsonData           JSONObject topObject    JSONObject  obj          JSONObject locationList    JSONObject  topObject get  LocationList            JSONArray array    JSONArray  locationList get  StopLocation            Iterator lt JSONObject gt  iterator   array iterator             while  iterator hasNext                   JSONObject jsonObj    JSONObject  iterator next                String name    String  jsonObj get  name                String id    String  jsonObj get  id                Planner getPlanner   setLocationName name               Planner getPlanner   setArrayID id

User · Answer

Non of them worked for me  I did this and it worked   To encode as a json   JSONObject obj   new JSONObject    obj put  productId   100     To decode   long temp    Long  obj get  productId

User · Answer

The question is kind of old  but I get a good result creating a function to convert an object in a Json string from a string variable to an integer function getInt arr  prop        var int      for  var i 0   i lt arr length   i              int   parseInt arr i  prop               arr i  prop    int            return arr       the function just go thru the array and return all elements of the object of your selection as an integer

User · Answer

I use a combination of json get   and instanceof to read in values that might be either integers or integer strings   These three test cases illustrate   int val  Object obj  JSONObject json   new JSONObject    json put  number   1   json put  string    10    json put  other    tree     obj   json get  number    val    obj instanceof Integer     int  obj    int  Integer parseInt  String  obj   System out println val    obj   json get  string    val    obj instanceof Integer     int  obj    int  Integer parseInt  String  obj   System out println val    try       obj   json get  other        val    obj instanceof Integer     int  obj    int  Integer parseInt  String  obj     catch  Exception e           throws exception

User · Answer

It depends on the property type that you are parsing   If the json property is a number  e g  5  you can cast to Long directly  so you could do    long  jsonObj get  id      with id   5  cast  5  to long    After getting the long you could cast again to int  resulting in    int   long  jsonObj get  id     If the json property is a number with quotes  e g   5    is is considered a string  and you need to do something similar to Integer parseInt   or Long parseLong     Integer parseInt jsonObj get  id       with id    5   convert  5  to Long   The only issue is  if you sometimes receive id s a string or as a number  you cant predict your client s format or it does it interchangeably   you might get an exception  especially if you use parseInt Long on a null json object   If not using Java Generics  the best way to deal with these runtime exceptions that I use is   if jsonObj get  id      null          do something here    int id  try      id   Integer parseInt jsonObj get  id   toString       catch NumberFormatException e         handle here     You could also remove that first if and add the exception to the catch  Hope this helps

User · Answer

At first  you create a BufferedReader on a FileReader to the file   Then  you create a new  JSONParser     object that parses the content read from the file   You cast the parsed Object to a JSONObject and get the id field   FileReader file new FileReader  1 json    BufferedReader write new BufferedReader file   Object obj new JSONParser   parse write   JSONObject jo    JSONObject  obj  long id  long jo get  id

User · Answer

Its very simple   Example JSON         value  1       int z   jsonObject getInt  value

User · Answer

You may use parseInt    int id   Integer parseInt jsonObj get  id       or better and more directly the getInt method    int id   jsonObj getInt  id

[java] How do I parse JSON into an int?

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