Nesting error on write GSON file by JsonWriter

Question

I would like to write to file by this function, but return always an exception NESTING PROBLEM. where is my error? The Exception appear in this line code:

writer.name("code").value(s);

please help me

this is the call:

---

userA.Write(file_name, getActivity().getBaseContext(),Prodotto);

---

public static void Write(String fileName,Context context,String s) {

         JsonWriter writer;
         File myDir, file_1;
         String file;

         try {
            myDir = context.getFilesDir();
            file = myDir.getAbsolutePath().toString();
            file_1 = context.getFileStreamPath(fileName);
            if(!file_1.exists()) { 
                //not exist file, create it             
                file_1 = new File(myDir, fileName);
            }
            //writer = new JsonWriter(new FileWriter(file+ "/"+ fileName));
            writer = new JsonWriter(new FileWriter(file+ "/"+ fileName));

            writer.beginObject(); // {
            writer.name("items"); // "items"

            writer.beginArray(); // [
            //ciclo for per tutti gli oggetti presenti
            writer.name("code").value(s); // "code" : 29
            writer.name("type").value(s); // "type"
            writer.name("name").value(s); // "name"
            writer.name("size").value(s); // "size"

            writer.endArray(); // ]      
            writer.endObject(); // }
            writer.close();

            System.out.println("Write - Done");

         } catch (IOException e) {
        e.printStackTrace();
         }

       }

My JSON structure is:

{ "items" : 
 [
   {
     "code" : "1234",
     "type" : "Pagnerine Cialda",
     "name" : "Pagnerine Cialda Sottozero/Estate",
      "size" : "ct"
   },
    {
      "code" : "1234",
     "type" : "Pagnerine Cartone",
     "name" : "Pagnerine Cartone 16B",
      "size" : "ct"
   },
    {
      "code" : "1234",
     "type" : "Zucchero",
     "name" : "Saccarosio",
      "size" : "kg"
   },
 ]
}

Answer 1

You can try this code. This is exactly what you need to build your JSON content:

    writer.beginObject().name("itemes").beginArray();

    writer.beginObject().name("code").value(1234);
    writer.name("type").value("Pagnerine Cialda").endObject();

    writer.beginObject().name("code").value(1234);
    writer.name("type").value("Pagnerine Cartone").endObject();

    writer.endArray().endObject().flush();

    writer.close();

Answer 2

From your code there is suspicious part:

      writer.beginArray(); // [
        //ciclo for per tutti gli oggetti presenti
        writer.name("code").value(s); // "code" : 29
        writer.name("type").value(s); // "type"
        writer.name("name").value(s); // "name"
        writer.name("size").value(s); // "size"

        writer.endArray(); // ]       

I suppose, you interesting to start array of Objects like: [{...}, {...}].

and each Object represents:

{"code": xxxxx, "type": xxx, "name": xxx, "size": xxxx}

Instead you got ["code": xxxxx, "type": xxx, "name": xxx, "size": xxxx].

You can't put Key-Value to array.

So maybe something like that:

      writer.beginArray(); // [
       writer.beginObject(); // { // open new object           
        writer.name("code").value(s); // "code" : 29
        writer.name("type").value(s); // "type"
        writer.name("name").value(s); // "name"
        writer.name("size").value(s); // "size"
        writer.endObject(); // }
        writer.endArray(); // ]     

as a side note

In Java, methods start from lower case later.