我有 3 个 API GET 调用。我的方法面临的问题是，该应用程序能够从两个 API 成功获取数据，并且我也能够在 UI 上显示它。但是，对于第三个 API 调用，由于以下错误，之前显示的数据消失了，这是不好的。
D/Volley: [380] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://example.com/api/search/getTwitterData?limit=10&tag=JavaScript 0x865f5dc2 NORMAL 3> [lifetime=6683], [size=10543], [rc=200], [retryCount=0]
如何使用 Volley 进行并发 API GET 调用而不丢失 UI 上的数据。有人可以指导我吗？
以下是我的代码的摘录。
public class StaggeredSearchActivity extends AppCompatActivity {
...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_staggered_search);
requestQueue = Volley.newRequestQueue(this);
Intent intent = getIntent();
String searchText = intent.getStringExtra("searchText");
// Three concurrent API GET Calls
getMediumData(searchText);
getExampleData(searchText);
getGoogleData(searchText);
recyclerView = findViewById(R.id.staggered_recycler_view);
staggeredGridLayoutManager = new StaggeredGridLayoutManager(2, LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(staggeredGridLayoutManager);
}
ArrayList<StaggeredCustomCard> dataset = new ArrayList<>();
private void getMediumData(String searchText) {
progressBar = findViewById(R.id.progressBar);
progressBar.setVisibility(View.VISIBLE);
String url = UrlConstants.getUrl() + searchText;
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest
(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
progressBar.setVisibility(View.INVISIBLE);
JSONArray array = response.getJSONArray("mediumposts");
...
dataset.add(new StaggeredCustomCard(user, userpost, postdate));
}
staggeredGridAdapter = new StaggeredGridAdapter(StaggeredSearchActivity.this, dataset);
recyclerView.setAdapter(staggeredGridAdapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// TODO: Handle error
progressBar.setVisibility(View.INVISIBLE);
}
});
jsonObjectRequest.setRetryPolicy(new DefaultRetryPolicy(
DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 15,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
requestQueue.add(jsonObjectRequest);
}
private void getExampleData(String searchText) {
...
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest
(Request.Method.GET, url, null, new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
try {
...
dataset.add(new StaggeredCustomCard(user, userpost, postdate));
staggeredGridAdapter = new StaggeredGridAdapter(StaggeredSearchActivity.this, dataset);
recyclerView.setAdapter(staggeredGridAdapter);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
...
}
});
jsonArrayRequest.setRetryPolicy(new DefaultRetryPolicy(
DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 15,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
requestQueue.add(jsonArrayRequest);
}
private void getGoogleData(String searchText) {
...
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest
(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
...
dataset.add(new StaggeredCustomCard(user, userpost, postdate));
}
staggeredGridAdapter = new StaggeredGridAdapter(StaggeredSearchActivity.this, dataset);
recyclerView.setAdapter(staggeredGridAdapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
...
}
});
jsonObjectRequest.setRetryPolicy(new DefaultRetryPolicy(
DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 15,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
requestQueue.add(jsonObjectRequest);
}
}
最佳答案
问题是您每次都在初始化适配器，这就是为什么一旦新的 API 调用您的数据就会丢失。我更喜欢下面的方法，这样可以帮助你，
在 ArrayList 中添加数据并通知适配器，
在 onCreate 中添加这一行，
staggeredGridAdapter = new StaggeredGridAdapter(StaggeredSearchActivity.this, dataset);
recyclerView.setAdapter(staggeredGridAdapter);
API回调响应的变化:
...
dataset.add(new StaggeredCustomCard(user, userpost, postdate));
循环后添加以下行
staggeredGridAdapter.notifyDataSetChanged();
适配器的变化
private ArrayList<StaggeredCustomCard> dataSet;
private Context context;
public MyAdapter(ArrayList<StaggeredCustomCard> dataSet, Context context) {
this.data = data;
this.context = context;
}
注意:不要在适配器上创建新对象。
关于java - 如何使用 Volley 进行并发 GET 调用？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57961172/