Android Volley 解析 JSON 并放入 listview 不起作用

Question

我在这里使用本指南：

http://www.androidhive.info/2014/07/android-custom-listview-with-image-and-text-using-volley/

我放了

System.out.println(error.getMessage());

在我下面的代码中，这是它显示给我的错误：

01-13 18:53:21.425 1915-1915/com.app.dev.myapplication I/System.out: org.json.JSONException: Value {"server_response":[{"first_name":"bob","last_name":"john","user_name":"bobthebuilder","avatar":"stringOfURL"}]} of type org.json.JSONObject cannot be converted to JSONArray
01-13 18:53:21.425 1915-1915/com.app.dev.myapplication D/Volley: [1] 2.onErrorResponse: SearchActivity

这是我的 JSON 代码：

{"server_response":[{"first_name":"bob","last_name":"john","user_name":"bobthebuilder","avatar":"stringOfURL"}]}

这是我的代码：

public class SearchActivity extends AppCompatActivity {

String JSON_STRING,sq,js_username,js_first_name,js_last_name,js_avatar;
EditText et_sq;
private static final String json_user_search_url = "http://www.domain.com/string.php";
private static final String TAG = SearchActivity.class.getSimpleName();
private List<SearchResults> movieList = new ArrayList<SearchResults>();
private ListView listView;
private CustomListAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_search);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    listView = (ListView) findViewById(R.id.listViewSearch);
    adapter = new CustomListAdapter(this, movieList);
    listView.setAdapter(adapter);

    // Creating volley request obj
    JsonArrayRequest movieReq = new JsonArrayRequest(json_user_search_url, new Response.Listener<JSONArray>() {

                @Override
                public void onResponse(JSONArray response) {
                    Log.d(TAG, response.toString());

                    // Parsing json
                    for (int i = 0; i < response.length(); i++) {
                        try {

                            JSONArray responseArray = response.getJSONArray("server_response");
                            JSONObject content = responseArray.getJSONObject(0);
                            SearchResults movie = new SearchResults();
                            movie.setUser_name(obj.getString("user_name"));
                            movie.setFirst_name(obj.getString("first_name"));
                            movie.setLast_name(obj.getString("last_name"));
                            movie.setAvatarUrl(obj.getString("avatar"));

                            // adding movie to movies array
                            movieList.add(movie);

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

                    }

                    adapter.notifyDataSetChanged();
                }
            }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            System.out.println(error.getMessage());
            VolleyLog.d(TAG, "Error: " + error.getMessage());

        }
    });

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(movieReq);
}

}

Answer 1

响应是一个 JSON 对象，其中“server_response”是它的唯一值。 “server_response”本身就是一个JSONObject包裹的JSONArray，所以需要改一下：

new JsonArrayRequest(json_user_search_url, new Response.Listener<JSONArray>() {

到：

new JsonObjectRequest(json_user_search_url, new Response.Listener<JSONObject>() {

以及覆盖 onResponse：

@Override
public void onResponse(JSONObject response) {

然后您可以访问响应并获取“server_response”，而无需像您一样循环访问内容：

@Override
public void onResponse(JSONObject response) {
    JSONArray responseArray = response.getJSONArray("server_response");
    JSONObject content = responseArray.getJSONObject(0);
    String firstName = content.getString("first_name");

    //get rest of the objects similarly...
}

编辑：在原始答案中犯了一个错误。 “server_response”是一个 JSONArray，在索引 0 处包含一个 JSON 对象。您访问 JSONObject 并将其内容存储为一个对象，然后提取其数据的键/值对。