本文介绍了在Volley onRsponse之外返回修改后的arrayList的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我需要在volley onResponse方法之外访问此arrayList.但它返回的是IndexOutOfBoundsException.
public ArrayList<QuestionAnswer> arrayList;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
arrayList = new ArrayList<>();
JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, getTalkById, new JSONObject(params),
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
JSONObject data = response.optJSONObject("data");
JSONArray highSchoolQuesAns = data.optJSONArray("questions").optJSONObject(0).optJSONArray("answers");
for (int i = 0; i < highSchoolQuesAns.length(); i++) {
String question = highSchoolQuesAns.optJSONObject(i).optString("question");
String answer = highSchoolQuesAns.optJSONObject(i).optString("answer");
arrayList.add(new QuestionAnswer(question, answer));
// adding new QuestionAnswer
}
Log.v("test",arrayList.get(0).question); // value is available here inside on response. And getting question of first arrayList element.
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("Error", "Error: " + error.getMessage());
}
}
);
request.setRetryPolicy(new DefaultRetryPolicy(
VolleyApplication.TIMEOUT,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
VolleyApplication.getInstance().getRequestQueue().add(request);
Log.v("test",arrayList.get(0).question); //java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
//This is where the issue is. AND I REALLY NEED TO access this arraylist outside of volley onResponse method
}
如您所见，我正在尝试登录两个地方.来自onResponse的日志确实返回了一些内容，但是在onResponse之外，它仅给出IndexOutOfBoundException.我做了很多调试，并意识到在onResponse arrayList之外是空的(并且我正在尝试访问一个不存在的空元素).在onResponse内部修改的ArrayList不能在外部访问.甚至是全局/类级别的变量
推荐答案
我建议您在截击成功响应后使用单独的方法，如下所示
I suggest you to have separate method after success response from volley as given below
public ArrayList<QuestionAnswer> arrayList;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
arrayList = new ArrayList<>();
JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, getTalkById, new JSONObject(params),
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
JSONObject data = response.optJSONObject("data");
JSONArray highSchoolQuesAns = data.optJSONArray("questions").optJSONObject(0).optJSONArray("answers");
for (int i = 0; i < highSchoolQuesAns.length(); i++) {
String question = highSchoolQuesAns.optJSONObject(i).optString("question");
String answer = highSchoolQuesAns.optJSONObject(i).optString("answer");
arrayList.add(new QuestionAnswer(question, answer));
// adding new QuestionAnswer
}
GetArrayValue();
Log.v("test",arrayList.get(0).question); // value is available here inside on response. And getting question of first arrayList element.
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("Error", "Error: " + error.getMessage());
}
}
);
request.setRetryPolicy(new DefaultRetryPolicy(
VolleyApplication.TIMEOUT,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
VolleyApplication.getInstance().getRequestQueue().add(request);
}
private void GetArrayValue(){
Log.v("test",arrayList.get(0).question);
}
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