Expected BEGIN_ARRAY but was BEGIN_OBJECT parsing JSON

Question

At the line

reader.beginArray();

I get the error:

expected beginarray but was beginobject.

I tried changing .beginArray() to .beginObject() but it doesn't work.

This code is part of a JsonParser

public List<Noticias> leerArrayNoticias(JsonReader reader) throws IOException {
    ArrayList<Noticias> noticias = new ArrayList<>();
    try {
        reader.beginArray();
        while (reader.hasNext()) {

            noticias.add(leerNoticia(reader));
        }
        reader.endArray();
    }catch(IOException e){
        e.printStackTrace();
    }catch(Exception e){
        e.printStackTrace();
    }
    return noticias;
}

Here is the Json that im trying to parse

{"noticias":
    [    
        {"idnoticias":"109","titulo":"nueva1","descripcion":"nuevo1"},
        {"idnoticias":"110","titulo":"nueva2","descripcion":"nuevo2"}
    ]
}

How does the JSON look like? The issue might be what the exception is saying, the json starts with an object instead of an array. You have said that you tried that, but can you give us that stack trace of that error? — engineercoding, Aug 17 '15 at 19:46
Trying whit an object sais "java.lang.IllegalStateException: Expected BEGIN_OBJECT but was NAME" — Joaquín Naftaly, Aug 17 '15 at 19:51

score 0 · Answer 1 · answered Aug 17 '15 at 20:11

You are reading the JSON wrong, since this JSON contains out of a JSON Object, then a JSON-Array with the key "noticias". So we have to read the JSON like this:

public void readNotes (final JsonReader reader) {
    // MARKING THE FOLLOWING FOR DELETION (SEE BELOW)
    reader.beginObject(); // First start reading the object
    reader.nextName(); // Read the noticias key, we don't need the actual key
    // END MARKING 
    reader.beginArray(); // Start the array of objects

    while (reader.hasNext()) {
        // Start the object and read it out
        reader.beginObject();

        reader.nextName();
        final int idnotes = reader.nextInt();

        reader.nextName();
        final String title = reader.nextString();

        reader.nextName();
        final String description = reader.nextString();

        // Do stuff with the variables

        // Close this object
        reader.endObject();
    }

    reader.endArray(); // Close the array

    // MARKING THE FOLLOWING FOR DELETION (SEE BELOW)
    reader.endObject(); // Close the object
    // END MARKING 
}

However, your JSON could be optimized as we do not need the first object. Then the JSON would be like this:

[    
    {"idnoticias":"109","titulo":"nueva1","descripcion":"nuevo1"},
    {"idnoticias":"110","titulo":"nueva2","descripcion":"nuevo2"}
]

If you have this JSON you can leave out the marked rules as above to make it work.

Expected BEGIN_ARRAY but was BEGIN_OBJECT parsing JSON

1 Answers1