Decoding JSON in Java - java

im really new to java through Eclipse android, and im trying to decode this line of JSON
{"FullName":"bobby Bloggs"}
But when i try to put it into an array through
JSONObject jsonObject = new JSONObject(httpData);
JSONObject feedObject = jsonObject.getJSONObject("FullName");
I hit an exception of
org.json.JSONException: Value bobby Bloggs at FullName of type java.lang.String cannot be converted to JSONObject
Thanks

You are trying to read a String, since {} within the JSON means it is an object. Everything between "" means it's a string. true/false a boolean (getBoolean) and numbers are an Integer (getInteger). Since you want the String you need to use.
String FullName = JSONObject.getString("FullName");

You are trying to get JSONObject out of JSON Object i.e jsonObject.getJSONObject("FullName"); and again assigning to JSONObject.
As suggested by Emanuel use getString to get the data of "FullName" as and assign to a String.
JSONObject jsonObj = new JSONObject(httpData);
String FullName = jsonObj.getString("FullName");
will work.

Related

Org json parsing keep getting error - is not a JSONObject

Im trying to parse id from following string json:
postResponse :{"success":true,"response_json":"{\"status\":200,\"message\":\"Success\",\"data\":{\"id\":\"f71233gg12\"}}"}
my code looks like below:
System.out.println("postResponse :"+postResponse);
JSONObject responseJson = new JSONObject(postResponse);
JSONObject jsonObjectA = responseJson.getJSONObject("response_json");
JSONObject jsonObjectB = jsonObjectA.getJSONObject("data");
String the_pdf_id = jsonObjectB.get("id").toString();
i keep getting the error:
org.json.JSONException: JSONObject["response_json"] is not a JSONObject.
what could be the reason? any solution for that?
As you can see on your data, the content at key response_json is not a an object, but only a string, another JSON-encoded string
// response_json value is a string
{"success":true,"response_json":"{\"status\":200,\"message\":\"Success\",\"data\":{\"id\":\"f71233gg12\"}}"}
// response_json value is an object
{"success":true,"response_json": {"status":200,"message":"Success","data":{"id":"f71233gg12"}}}
You need a second parse level
JSONObject jsonObjectA = new JSONObject(responseJson.getJSONString("response_json"));

Java read Json array in Json object

I have a String like this:
{"api_authentication":{"api_response":{"token":"XXXXXXXXXXXXXXXXXXXXXXXXX","firstname":"John","disabled":false,"attempts":0,"id":123,"lastname":"Malkovitch","expire":false,"status":0}}}
I can turn this string into an object:
JSONObject jobj = new JSONObject(response);
But I don't find how to get the token value, I tried creating JSONArrays but i get a not found exception.
You can do it like this ;
final JSONObject api_authentication = jobj.getJSONObject("api_authentication");
final JSONObject api_response = api_authentication.getJSONObject("api_response");
System.out.println(api_response.getString("token"));
if JSON any value in curlybrackets { ... } , this is jsonObject . If values are in [ ... ], this is JsonArray. Also you can get which one is object or array, and get it relevant fields from this. So all of json elements are with curly bracket in your problem. Get it as JsonObject.
this might work by the look of what you have posted. The posted code snippet shows that it is a single JSON object and not a JSONArray.
Hence try the following:
JSONObject jobj = new JSONObject(response);
String newtoken = jobj.getJSONObject("api_authentication").getJSONObject("api_response").getString("token"); //declare the variable `newtoken` somhwere before of a desired type
You could try something like:
Object tokenValue = jobj.getJSONObject("api_authentication").getJSONObject("api_response").get("token");
After that you can cast the object to the desired type or use something like getString(.) straightaway.

how to get the name of json object from my json array

I am trying to get the name of my json key from my jsonarray but not able to take in java.
[{"ParamName":"param1","DefaultValue":"","Hidden":"Hidden","LinkedParameter":"city"}]
I just want to take name of key like i only want to take "ParamName" and need to check
if (ParamName == "ParamName") {
Then do this.
}
You can convert this to JSON object.
JSONArray json = (JSONArray)new JSONParser().parse("[{\"ParamName\":\"param1\",
\"DefaultValue\":\"\",\"Hidden\":\"Hidden\",\"LinkedParameter\":\"city\"}]");
JSONObject obj= (JSONObject) json.get(0);
if("ParamName".equals(obj.get("ParamName"))){
}

How to know if JSON string can be converted to JSONObject without errors?

How to handle this so that it wont give the following error
JSONObject dataObject = new JSONObject(data);
String currentDynamicKey = "7";
JSONObject currentDynamicValue = dataObject.getJSONObject(currentDynamicKey);
error:
org.json.JSONException: Value at 7 of type java.lang.String cannot be converted to JSONObject
json data:
{"2":{"id":2,"title":"Battleship game","enabled":"1","connection_alert":"1","prot":"2","port":"6410","analysis":"1","send_data":"Analysis Data box","regex":"\/HTTP\/1.1 404 Not Found\/","send_on":false,"analysis_alert_title":"404","analysis_alert_body":"not found","analysis_alert_body_false":"found"},"7":""}
as you can see at the end the 7 in empty. what can I do to check if it is empty?
Just use optJSONObject(String name) instead getJSONObject(String name):
Returns the value mapped by name if it exists and is a JSONObject. Returns null otherwise.
And then check returned value.

Android: JSONObject cannot be converted to JSONArray

I want to get data from php file to Android using JSON. This is my code:
....
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
JSONArray timeline = new JSONArray(data);
JSONObject last = timeline.getJSONObject(0);
return last;
When I debug the program there is JSONException on this line:
JSONObject last = timeline.getJSONObject(0);
Data is {"a":1,"b":2,"c":3,"d":4,"e":5} and the Exception is:
org.json.JSONException: Value {"d":4,"e":5,"b":2,"c":3,"a":1} of type org.json.JSONObject cannot be converted to JSONArray
The exception message is quite explicit and a look at the JSON syntax diagrams should be illustrative. The JSON string that your code received is:
{"a":1,"b":2,"c":3,"d":4,"e":5}
This string represents an object, not an array. An example of an array would be this:
[1, 2, 3, 4, 5]
or even this:
[{"a":1,"b":2,"c":3,"d":4,"e":5}]
Note that starting and closing brackets.
I think that you will find that the exception location is slightly misleading. I don't know if it is a result of some sort of lazy initialization or something else, but I believe that the cause is actually this line:
JSONArray timeline = new JSONArray(data);
Since the data string represents a JSON object and not an array, this operation is clearly impossible.
In Json arrays are described using [].
There you define an object with five attributes.
JSONArray timeline = new JSONArray(data);
// change JSONArray to JSONObject
JSONObject timeline = new JSONObject(data);// Like This
Your JSON data is not an array.
Your json response is in Object form, not in Array form.So you have to simply parse your json object. Suppose "data" is the JSONObject tag in response.
Following is the way of Parsing:
HttpEntity e = r.getEntity();
String result = EntityUtils.toString(e);
JSONObject response=new JSOBObject(result);
JSONOBject Data=response.getJSONObject("data");
int a=Data.getInt("a");
int b=Data.getInt("b");
int c=Data.getInt("c");
int d=Data.getInt("d");
int e=Data.getInt("e");
Thanks.

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