We Keep Coding

Parse JSON having both Escape & Unescape characters in JAVA using Jayway

I receive the below json as an input to my program:
{
"shopping": {
"cart": {
"items": [{
"iturl" : "https://www.google.com/",
"itdesc" : "Item’s box includes the below contents:\n a.adaptor \n b.sdfd"
}]
}
}
}
We are using jayway jsonpath to parse this data and do some processing and return the final value as a string.
when we parse it with the default jsonpath configuration, I get the iturl modified as "https:\/\/www.google.com\/"
Tried changing the JSONProvider to JacksonJsonProvider (by referring Jsonpath with Jackson or Gson) and the issue with the url is solved but, the value of itdesc is now coming to new line (due to \n) making it an invalid json.
I cannot specifically handle for each field as the incoming data will be dynamic.
Is there any proper way to parse this kind of JSON in java. Thanks in advance for your help

Try adding one more escaping level before parsing the string, the string parser's gonna give you "\n" for "\\n".
For example, parsing with Jackson ObjectMapper.
objectMapper.readValue(jsonString.replace("\\", "\\\\"), Any.class);

{
"shopping": { <-- JSONObject
"cart": { <-- JSONObject
"items": [{ <-- JSONArray
"iturl" : "https://www.google.com/", <-- JSONObject inside JSONAray
"itdesc" : "Item’s box includes the below contents:\n a.adaptor \n b.sdfd"
}]
}
}
}
if this data json come from http connection.
this json must be a string format fisrt,
and try using org.json.simple
so do like this :
private void readData() {
String Body = (response json string from connection);
JSONParser parse = new JSONParser();
String iturl = null;
String itdesc = null;
try {
JSONObject shopping = (JSONObject) parse.parse(Body);
JSONObject cart= (JSONObject) shopping.get("cart");
JSONArray items = (JSONArray ) cart.get("items ");
items.forEach((k)-> {
JSONObject inside = (JSONObject) k;
iturl = inside.get("iturl");
itdesc = inside.get("itdesc");
});
}catch ( ParseException e) {
e.printStackTrace();
}
}
if this come from file.json combine with reader :
private static final File jsonData = new File(file.json);
private void callData() {
String iturl = null;
String itdesc = null;
try {
Reader reader = new FileReader(marketList);
JSONParser parse = new JSONParser();
JSONObject shopping = (JSONObject) parse.parse(reader);
JSONObject cart= (JSONObject) shopping.get("cart");
JSONArray items = (JSONArray ) cart.get("items ");
items.forEach((k)-> {
JSONObject inside = (JSONObject) k;
iturl = inside.get("iturl");
itdesc = inside.get("itdesc");
});
} catch (IOException | ParseException e) {
e.printStackTrace();
}
}

Getting and saving JSON array from Socket.IO [duplicate]

This question already has answers here:
ArrayIndexOutOfBoundsException [closed]
(2 answers)
Closed 5 years ago.
Im get from my server an array of objects like this:
Log.i(TAG, "Destinos obtenidos: "+ destinosRuta);
Value of log -
Destinos obtenidos [{"Latitud":41.40404,"nombreDestino":"Barcelona","IDR":5,"IDD":6,"Longitud":2.168679},{"Latitud":37.408424,"nombreDestino":"Sevilla","IDR":5,"IDD":7,"Longitud":-5.9681},{"Latitud":38.92298,"nombreDestino":"Mérida","IDR":5,"IDD":4,"Longitud":-6.363121}]
which I want to stock on SharedPreferences, I have used the code from this answer:
putStringSet and getStringSet
But I don't know if i need to use an array of object, or I need to convert in an array of String, this is my code:
private Emitter.Listener onNuevaRuta = new Emitter.Listener() {
#Override
public void call(Object... args) {
runOnUiThread(new Runnable() {
#Override
public void run() {
JSONObject data = (JSONObject) args[0];
String destinosRuta = "";
try {
destinosRuta = data.getString("destinosRuta");
}catch (JSONException e) {
return;
}
//destinosRuta has the previous value
ArrayList<String> listaDestinos = new ArrayList<String>(Arrays.asList(destinosRuta));
setStringArrayPref(getApplicationContext(), "listaDestinos", listaDestinos);
listaDestinos = getStringArrayPref(getApplicationContext(), "listaDestinos");
String origen = listaDestinos.remove(0);
String destino = listaDestinos.remove(0);
setStringArrayPref(getApplicationContext(), "listaDestinos", listaDestinos);
...
And, like the previous link, I have used his function:
public static void setStringArrayPref(Context context, String key, ArrayList<String> values) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = prefs.edit();
JSONArray a = new JSONArray();
for (int i = 0; i < values.size(); i++) {
a.put(values.get(i));
}
if (!values.isEmpty()) {
editor.putString(key, a.toString());
} else {
editor.putString(key, null);
}
editor.commit();
}
public static ArrayList<String> getStringArrayPref(Context context, String key) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
String json = prefs.getString(key, null);
ArrayList<String> destinos = new ArrayList<String>();
if (json != null) {
try {
JSONArray a = new JSONArray(json);
for (int i = 0; i < a.length(); i++) {
String destino = a.optString(i);
destinos.add(destino);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
return destinos;
}
And i get an error when I'm tring to removed the first element of listaDestinos here:
String origen = listaDestinos.remove(0);
String destino = listaDestinos.remove(0); <--Error
FATAL EXCEPTION: main
Process: tfg.clienteandroid, PID: 17276
java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at
java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
at java.util.ArrayList.remove(ArrayList.java:403)
at tfg.clienteandroid.mapaActivity$3$1.run(mapaActivity.java:320)
Any idea? I want to remove twice and be able to use both objects from my array.

You don't need to store a list object. If you have your server already returning JSON, you can directly store that.
JSONObject data = (JSONObject) args[0];
String response = String.valueOf(data);
//... Or parse out the data you need
sharedPrefs.putString("response", response);
Convert the string into a JSON object or whatever on the way out and optionally parse it into actual Java objects (you can use Jackson or Gson to help you with that)
Anyway, not sure why you think you need to remove an object from a list in order to extract a value; besides, it looks like you only added one value to your list, not two. The Arrays.asList() method is creating you a list of one string. You can't remove two objects from that list
So, try to debug your code better with some breakpoints and more log statements.
In other words, you seem to have a problem parsing your data, not just using SharedPreferences
For example,
data.getString("destinosRuta");
Is that actually a string? Or an array? If an array, use the according method of the JSONObject class to get an array.

Save your json to preference like this
SharedPreferences appSharedPrefs = PreferenceManager.getDefaultSharedPreferences(this.getApplicationContext());
Editor prefsEditor = appSharedPrefs.edit();
prefsEditor.putString("MyObject", destinosRuta);
prefsEditor.commit();
And get it when to use and convert to ArrayList or List as below
SharedPreferences appSharedPrefs = PreferenceManager.getDefaultSharedPreferences(this.getApplicationContext());
Gson gson = new Gson();
String json = appSharedPrefs.getString("MyObject", "");
Type type = new TypeToken<List<Object>>(){}.getType();
List<Object> objects= gson.fromJson(json, type);

JSON stored as string. Cant seem to parse it - Java

This is what I have to read text in JSON format from a website. But i get the error
Java.lang.ClassCastException: org.json.simple.JSONObject cannot be
cast to org.json.simple.JSONArray
This is driving me nuts. Can anyone help? I also need to check this string for all instances of "Username" and run something for each of them.
public class CommandCheck implements CommandExecutor {
private String username;
private static String host = "example.com";
private URL url;
private String apiKey = main.getNode("API-KEY");
#Override
public boolean onCommand(CommandSender sender, Command cmd, String label, String[] arg3) {
try {
this.url = new URL(CommandCheck.host);
final URLConnection conn = this.url.openConnection();
conn.setConnectTimeout(5000);
if (this.apiKey != null) {
conn.addRequestProperty("x-api-key", this.apiKey);
}
conn.addRequestProperty("User-Agent", main.USER_AGENT);
conn.setDoOutput(true);
final BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
final String response = reader.readLine();
sender.sendMessage(response); //Im just dumping the raw String for the person running the command to see Debug mostly
final JSONArray array = (JSONArray) JSONValue.parse(response);
if (array.isEmpty()) {
sender.sendMessage("The Array appears to be empty");
return false;
}
JSONObject latestUpdate = (JSONObject) array.get(array.size() - 1);
username = (String) latestUpdate.get("Username");
sender.sendMessage("whitelist add" + username);
return true;
} catch (final IOException e) {
if (e.getMessage().contains("HTTP response code: 403")) {
sender.sendMessage("I think there is an API key issue");
} else {
sender.sendMessage("Problem of unknown orign");
}
return false;
}
}

Try changing the following line:
final JSONArray array = (JSONArray) JSONValue.parse(response);
to:
final JSONObject jsObj = (JSONObject) JSONValue.parse(response);
Can you provide the JSON String you are trying to parse? I.e. the value of response?

JsonReader jsonReader = Json.createReader(new StringReader(response.readEntity(String.class)));
JsonArray jsonArray = jsonReader.readArray();
ListIterator l = jsonArray.listIterator();
while ( l.hasNext() ) {
JsonObject j = (JsonObject)l.next();
JsonObject ciAttr = j.getJsonObject("ciAttributes") ;

org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray means that you are trying to convert the json object into the json array. if your response in the json object as a response then you first need it to convert in the Json object.
after converting you can get the the Json array from the json object using the get("key-name")
JSONObject resObj = new JSONObject(responseString);
JSONArray resArray = resObj.getJSONArray("Username");
for (int i=0; i<resArray.length(); i++)
String resultString = resArray.getString(i);
it gives you all usersname.
i think this code helps you to solve your problem.

error Class cast exception in main

I am trying to convert json file into csv file and I am using following code for that
public File convert(File toConvert) {
// TODO Auto-generated method stub
String JsonString = "{\"value\": [{\"name\",\"kind\":\"url\":]}";
JSONParser file = new JSONParser();
Object obj = file;
JSONObject jsonfile = (JSONObject) obj; //JSONObject from map interface
String name = (String) jsonfile.get("name");
System.out.println(name);
String kind = (String) jsonfile.get("kind");
System.out.println(kind);
JSONArray url = (JSONArray) jsonfile.get("url"); //JSONArray from list interface
Iterator<String> iterator = url.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
return toConvert ;
}
and my json file has a huge data and it looks like this
{
"value":[
{
"name":"accountleadscollection","kind":"EntitySet","url":"accountleadscollection"
},{
"name":"accounts","kind":"EntitySet","url":"accounts"
},{
"name":"activitymimeattachments","kind":"EntitySet","url":"activitymimeattachments"
},{
"name":"activityparties","kind":"EntitySet","url":"activityparties"
},{
"name":"activitypointers","kind":"EntitySet","url":"activitypointers"
},{
"name":"annotations","kind":"EntitySet","url":"annotations"
},{
"name":"annualfiscalcalendars","kind":"EntitySet","url":"annualfiscalcalendars"
},{...............
whenever I am trying to execute the code i am getting this error,Exception in thread "main" java.lang.ClassCastException. Is the logic I am following is correct or can anyone provide a better code for that, and I am implementing an interface which is having this method.

Convert the String in JSONObject.
Get the Array in the JSONObject by using the method getJSONArray("arraName").
If the array consist of Object then Iterate the array and then get the object using the index using method getJSONObject(index).
Now get the value using the key.
Here is the sample code in which you can do this.
Parse JSON from the string:
public void convert() throws JSONException {
String jsonString = readFile("prop.json"); //URL of your json file
JSONObject jsonObj = new JSONObject(jsonString);
JSONArray jsonArr = jsonObj.getJSONArray("value");
for (int j = 0; j < jsonArr.length(); j++) {
JSONObject tempJsonObj = jsonArr.getJSONObject(j);
System.out.println(tempJsonObj.get("name"));
System.out.println(tempJsonObj.get("kind"));
System.out.println(tempJsonObj.get("url"));
}
}
Read JSON file:
public String readFile(String filename) {
String result = "";
try {
BufferedReader br = new BufferedReader(new FileReader(filename));
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
line = br.readLine();
}
result = sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
return result;
}

How to parse JSON Array (Not Json Object) in Android

I have a trouble finding a way how to parse JSONArray.
It looks like this:
[{"name":"name1","url":"url1"},{"name":"name2","url":"url2"},...]
I know how to parse it if the JSON was written differently (In other words, if I had json object returned instead of an array of objects).
But it's all I have and have to go with it.
*EDIT: It is a valid json. I made an iPhone app using this json, now I need to do it for Android and cannot figure it out.
There are a lot of examples out there, but they are all JSONObject related. I need something for JSONArray.
Can somebody please give me some hint, or a tutorial or an example?
Much appreciated !

use the following snippet to parse the JsonArray.
JSONArray jsonarray = new JSONArray(jsonStr);
for (int i = 0; i < jsonarray.length(); i++) {
JSONObject jsonobject = jsonarray.getJSONObject(i);
String name = jsonobject.getString("name");
String url = jsonobject.getString("url");
}

I'll just give a little Jackson example:
First create a data holder which has the fields from JSON string
// imports
// ...
#JsonIgnoreProperties(ignoreUnknown = true)
public class MyDataHolder {
#JsonProperty("name")
public String mName;
#JsonProperty("url")
public String mUrl;
}
And parse list of MyDataHolders
String jsonString = // your json
ObjectMapper mapper = new ObjectMapper();
List<MyDataHolder> list = mapper.readValue(jsonString,
new TypeReference<ArrayList<MyDataHolder>>() {});
Using list items
String firstName = list.get(0).mName;
String secondName = list.get(1).mName;

public static void main(String[] args) throws JSONException {
String str = "[{\"name\":\"name1\",\"url\":\"url1\"},{\"name\":\"name2\",\"url\":\"url2\"}]";
JSONArray jsonarray = new JSONArray(str);
for(int i=0; i<jsonarray.length(); i++){
JSONObject obj = jsonarray.getJSONObject(i);
String name = obj.getString("name");
String url = obj.getString("url");
System.out.println(name);
System.out.println(url);
}
}
Output:
name1
url1
name2
url2

Create a class to hold the objects.
public class Person{
private String name;
private String url;
//Get & Set methods for each field
}
Then deserialize as follows:
Gson gson = new Gson();
Person[] person = gson.fromJson(input, Person[].class); //input is your String
Reference Article: http://blog.patrickbaumann.com/2011/11/gson-array-deserialization/

In this example there are several objects inside one json array. That is,
This is the json array: [{"name":"name1","url":"url1"},{"name":"name2","url":"url2"},...]
This is one object: {"name":"name1","url":"url1"}
Assuming that you have got the result to a String variable called jSonResultString:
JSONArray arr = new JSONArray(jSonResultString);
//loop through each object
for (int i=0; i<arr.length(); i++){
JSONObject jsonProductObject = arr.getJSONObject(i);
String name = jsonProductObject.getString("name");
String url = jsonProductObject.getString("url");
}

public class CustomerInfo
{
#SerializedName("customerid")
public String customerid;
#SerializedName("picture")
public String picture;
#SerializedName("location")
public String location;
public CustomerInfo()
{}
}
And when you get the result; parse like this
List<CustomerInfo> customers = null;
customers = (List<CustomerInfo>)gson.fromJson(result, new TypeToken<List<CustomerInfo>>() {}.getType());

A few great suggestions are already mentioned.
Using GSON is really handy indeed, and to make life even easier you can try this website
It's called jsonschema2pojo and does exactly that:
You give it your json and it generates a java object that can paste in your project.
You can select GSON to annotate your variables, so extracting the object from your json gets even easier!

My case
Load From Server Example..
int jsonLength = Integer.parseInt(jsonObject.getString("number_of_messages"));
if (jsonLength != 1) {
for (int i = 0; i < jsonLength; i++) {
JSONArray jsonArray = new JSONArray(jsonObject.getString("messages"));
JSONObject resJson = (JSONObject) jsonArray.get(i);
//addItem(resJson.getString("message"), resJson.getString("name"), resJson.getString("created_at"));
}

Create a POJO Java Class for the objects in the list like so:
class NameUrlClass{
private String name;
private String url;
//Constructor
public NameUrlClass(String name,String url){
this.name = name;
this.url = url;
}
}
Now simply create a List of NameUrlClass and initialize it to an ArrayList like so:
List<NameUrlClass> obj = new ArrayList<NameUrlClass>;
You can use store the JSON array in this object
obj = JSONArray;//[{"name":"name1","url":"url1"}{"name":"name2","url":"url2"},...]

Old post I know, but unless I've misunderstood the question, this should do the trick:
s = '[{"name":"name1","url":"url1"},{"name":"name2","url":"url2"}]';
eval("array=" + s);
for (var i = 0; i < array.length; i++) {
for (var index in array[i]) {
alert(array[i][index]);
}
}

URL url = new URL("your URL");
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
BufferedReader reader;
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
//setting the json string
String finalJson = buffer.toString();
//this is your string get the pattern from buffer.
JSONArray jsonarray = new JSONArray(finalJson);