问题
I'm trying to send arraylist containing numbers as parameter in volley request and then parse it and display the values (in string) in toast. But I'm getting null in response. I would like to know where is the problem.
json response:
{
"got_members": [
"1",
"2"
]
}public class SearchFragment extends Fragment{
Button checkme;
private static final String ADDMEM = "http://www.example.com/api/event/addmembers/", KEY_ADDMEM = "adding_members";
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.searchfragment, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
checkme = (Button)view.findViewById(R.id.checkme);
checkme.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
checkarraylist();
}
});
}
private void checkarraylist(){
StringRequest stringRequest = new StringRequest(Request.Method.POST, ADDMEM,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
if(response != null){
try {
JSONObject object = new JSONObject(response);
} catch (JSONException e) {
e.printStackTrace();
}
}else {
Toast.makeText(getActivity(), response, Toast.LENGTH_SHORT).show();
try {
JSONArray itemArray = new JSONObject(response).getJSONArray("got_members");
for (int i = 0; i < itemArray.length(); i++) {
String value = itemArray.getString(i);
Toast.makeText(getActivity(), "Result:" + value + "\n", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getActivity(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
ArrayList<String> strings = new ArrayList<String>();
strings.add("10");
strings.add("20");
strings.add("30");
Map<String, String> params = new HashMap<String, String>();
int i=0;
for(String object: strings){
params.put("adding_members["+(i++)+"]", object);
System.out.println(object);
}
/* String array[]=strings.toArray(new String[strings.size()]);
for(String k: array)
{
params.put("adding_members", k);
System.out.println(k);
} */
return params;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
return params;
}
};
RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
requestQueue.add(stringRequest);
}
}回答1:
First in your Object in ArrayList: create JSONObjectmethod name as getJSONObject, like this
public class EstimateObject {
String id, name, qty, price, total;
public EstimateObject(String id, String name, String qty, String price, String total, int position)
{
this.id = id;
this.name = name;
this.qty = qty;
this.price = price;
this.total =total;
this.position = position;
}
public JSONObject getJSONObject() {
JSONObject obj = new JSONObject();
try {
obj.put("Id", id);
obj.put("Name", name);
obj.put("Qty",qty);
obj.put("Price", price);
obj.put("Total", total);
}
catch (JSONException e) {
e.printStackTrace();
}
return obj;
}
Aftrer Here is how I converted it,in my activity
JSONObject JSONestimate = new JSONObject();
JSONArray myarray = new JSONArray();
for (int i = 0; i < items.size(); i++) {
try {
JSONestimate.put("data:" + String.valueOf(i + 1), items.get(i).getJSONObject());
myarray.put(items.get(i).getJSONObject());
} catch (JSONException e) {
e.printStackTrace();
}
}
Log.d("JSONobject: ", JSONestimate.toString());
Log.d("JSONArray : ", myarray.toString());
Here i converted both type JSONObject and JSONArray.
After in
map.put("jsonarray",myarray.toString());
回答2:
You have to parse the JSONObject first . Then get the JSONArray . like this way ->
try {
JSONArray array = new JSONObject(response).getJSONArray("got_members");
for (int i = 0; i < itemArray.length(); i++) {
String value=itemArray.getString(i);
//Log.e("json", i+"="+value);
Toast.makeText(getActivity(), "Result:" + value+"\n", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
回答3:
You need to add the following code alongwith your overriding getParams() function
@Override
protected Map<String, String> getParams() {
//Parameters added here
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
return params;
}
Also you need to change this line
JSONArray itemArray = new JSONArray("got_members");
to
JSONArray itemArray = new JSONObject(response).getJSONArray("got_members");
回答4:
This may be the late response but as per response example this could help a bit
try {
JSONObject object = new JSONObject();
JSONArray jsonArray = new JSONArray();
for (int i = 0; i < 2; i++) {
String someString = String.valueOf(i);
jsonArray.put(someString);
}
object.put("got_members", jsonArray);
} catch (JSONException e) {
e.printStackTrace();
}
回答5:
First get the response in JsonObject and then retreive the JsonArray or change the string request to JsonArray request
try {
JsonObject object=new JsonObject(response)
JSONArray itemArray = new JSONArray("got_members");
for (int i = 0; i < itemArray.length(); i++) {
String value=itemArray.getString(i);
//Log.e("json", i+"="+value);
Toast.makeText(getActivity(), "Result:" + value+"\n", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getActivity(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
or simply use JSONArray array = new JSONObject (response).getJSONArray("got_members");
回答6:
try this instead of sending whole arraylist,if you are sending contact
@Override
protected Map<String, String> getParams() throws AuthFailureError {
ArrayList<String> numbers = new ArrayList<String>();
Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null);
while (phones.moveToNext())
{
String name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
numbers.add("\n"+name+"\n"+phoneNumber+"\n");
}
phones.close();
Map<String, String> params = new HashMap<String, String>();
int i=0;
for(String object: numbers){
params.put("a"+(i++), object);
if(i==10)
break;
}
return params;
now handle this on server side
$response=array();$response["res"]=array(); foreach($_POST as $k => $v) {
if(strpos($k, 'a') === 0) {
$res=array();
$ab=$k = $v;
$res["name"]=$ab;array_push($response["res"],$res);}}echo json_encode($response);
now after response
@Override
public void onResponse(String response) {
try {
JSONObject stdent = new JSONObject(response);
JSONArray students = stdent.getJSONArray("res");
for (int i = 0; i < students.length(); i++) {
String ab=students.getString(i);
Toast.makeText(getApplicationContext(), ab, Toast.LENGTH_LONG).show();
}
来源：https://stackoverflow.com/questions/36741810/send-arraylist-as-parameter-in-volley-request