Why am I getting the \'java.lang.IllegalStateException: Expected BEGIN_OBJECT but was NAME at line 1 column 73\' error when parsing JSON data using GSON in Android?

How to Parse JSON Data Using GSON in Android: Error Resolution

When parsing JSON data using GSON in Android, you may encounter the error: "java.lang.IllegalStateException: Expected BEGIN_OBJECT but was NAME at line 1 column 73." This error indicates a syntax issue in the JSON data, specifically, a missing opening brace.

Possible Solution

To resolve this issue, ensure that your JSON data is correctly formatted and contains both an opening and closing curly brace. For example:

<code class="json">{
    "count": "12",
    "colbreak": 1,
    ...
    "seek": 0
}</code>

Common Cause

One common cause of this error is receiving JSON data that is stored in a file or downloaded from a server as a string. In such cases, the string may not be properly encoded or prefixed, which can lead to parsing errors.

Custom Class Modification

In your code, you are using Java reflection to create a custom class, GsonParse, to represent the JSON data structure. This approach is generally not recommended. Instead, create explicit getter and setter methods for each field in GsonParse. Additionally, annotate the class and field names with @SerializedName to match the JSON property names.

Here's an example:

<code class="java">public class GsonParse {

    @SerializedName("count")
    private String count;

    @SerializedName("colbreak")
    private String colbreak;

    @SerializedName("name")
    private String name;

    @SerializedName("score")
    private String score;

    @SerializedName("Words")
    private List<Words> mWords = new ArrayList<>();

    @SerializedName("seek")
    private String seek;

    // Add getters and setters here...
}</code>

UTF-8 Encoding

Ensure that your JSON data is properly encoded in UTF-8 format. When receiving JSON data over HTTP, the server should respond with the appropriate Content-Type header (e.g., 'application/json; charset=utf-8').

Improved Parsing Method

Here's an improved version of your parsing method that uses a Reader:

<code class="java">public static <T> ArrayList<T> JsonParse(T t, Reader reader) {
    ArrayList<T> lcs = new ArrayList<>();
    try {
        Gson gson = new Gson();
        JsonReader jsonReader = new JsonReader(reader);

        jsonReader.beginObject();
        while (jsonReader.hasNext()) {
            T cse = (T) gson.fromJson(jsonReader, t.getClass());
            lcs.add(cse);
        }
        jsonReader.endObject();
        jsonReader.close();
    } catch (UnsupportedEncodingException | IOException e) {
        e.printStackTrace();
    }
    return (ArrayList<T>) lcs;
}</code>

Usage

To use this method, create a Reader from your source (e.g., file or HTTP response) and pass it to the JsonParse method:

<code class="java">InputStream ims = assetManager.open("file.txt");
Reader reader = new InputStreamReader(ims, "UTF-8");

ArrayList<GsonParse> gsonObjects = JsonParse(new GsonParse(), reader);</code>

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