我通过Volley获取json数据。我遇到的问题
是从未调用过Volley的onResponse，因此不会解析和显示数据。
示例JSON数据
{
"title": "This is a sample text title title",
"cat": {
"origin" : "United states",
"target" : "Asia",
},
"content": "Lorem ipsum ipsum trxt hag jlak jshss jsyts pjqgq uuqtyq usiuqjo uwywh",
}
NewsActivity
public class NewsDetails extends AppCompatActivity {
private final String TAG = "NewsDetails";
private ProgressDialog mProgresscircle;
TextView newsTitle, newsOrigin, newsContent;
//private int news_id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_news_details);
newsTitle = (TextView) findViewById(R.id.dnews_title);
newsOrigin = (TextView) findViewById(R.id.dnews_origin);
newsContent = (TextView) findViewById(R.id.dnews_content);
if (NetworkCheck.isAvailableAndConnected(this)) {
//Calling method to load newss
loadNews();
} else {
final Context context;
context = this;
final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
alertDialog.setTitle(R.string.alert_titl);
alertDialog.setCancelable(false);
alertDialog.setIcon(R.mipmap.ic_launcher);
alertDialog.setMessage(R.string.failed_news);
alertDialog.setPositiveButton(R.string.alert_retry, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (!NetworkCheck.isAvailableAndConnected(context)) {
alertDialog.show();
} else {
loadNews();
}
}
});
alertDialog.setNegativeButton(R.string.alert_cancel, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
alertDialog.show();
}
}
private void loadNews() {
Log.d(TAG, "loadNews called");
mProgresscircle = new ProgressDialog(NewsDetails.this);
mProgresscircle.setCancelable(false);
mProgresscircle.setMessage(null);
mProgresscircle.show();
int news_id = getIntent().getIntExtra("NewsId", -1);
Toast.makeText(NewsDetails.this, "News id is" + news_id, Toast.LENGTH_SHORT).show();
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DetailConfig.GET_DURL + news_id,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, "onResponse called NewsDetails");
//Dismissing progressbar;
if (mProgresscircle != null) {
mProgresscircle.dismiss();
}
//Calling method to parse json array
parseNews(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
//Creating request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to queue
requestQueue.add(djsonArrayRequest);
}
//This method will parse json data of news
private void parseNews(JSONArray jsonArray) {
Log.d(TAG, "Parsing news array");
for (int i = 0; i<jsonArray.length(); i++) {
JSONObject jsonObject = null;
try {
jsonObject = jsonArray.getJSONObject(i);
String title = jsonObject.getString(DetailConfig.TAG_DPOST_TITLE);
newsTitle.setText(title);
JSONObject pOrigin = jsonObject.getJSONObject("cat");
String origin = pOrigin.getString("origin");
newsOrigin.setText(origin);
String content = jsonObject.getString(DetailConfig.TAG_DPOST_CONTENT);
newsContent.setText(content);
} catch (JSONException w) {
w.printStackTrace();
}
}
}
}
我知道的事情
所以，我的问题是为什么onResponse没有被调用，我应该如何解决它？
答案 0 :(得分：4)
您应该使用 JsonObjectRequest 而不是JsonArrayRequest，因为您在响应中获得了jsonobject。 要获得更多知识，您可以通过Volley tutorial
答案 1 :(得分：3)
/ *你得到了json的响应，但你的响应监听器方法是让Json Array用下面的代码替换你的代码，并在你的错误监听器方法中添加一个调试点* /
private void loadNews() {
Log.d(TAG, "loadNews called");
mProgresscircle = new ProgressDialog(NewsDetails.this);
mProgresscircle.setCancelable(false);
mProgresscircle.setMessage(null);
mProgresscircle.show();
int news_id = getIntent().getIntExtra("NewsId", -1);
Toast.makeText(NewsDetails.this, "News id is" + news_id, Toast.LENGTH_SHORT).show();
final JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
DetailConfig.GET_DURL, requestParam,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d("Debug", response.toString());
//TODO parsing code
parseNews(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("", "Error: " + error.getMessage());
}
});
//Creating request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to queue
requestQueue.add(djsonArrayRequest);
}
// or replace this code into your into your loadNews method
final JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
DetailConfig.GET_DURL, requestParam,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d("Debug", response.toString());
//TODO parsing code
parseNews(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("", "Error: " + error.getMessage());
}
});
**
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