使用Android Volley将各种数据类型从android发送到php

Question

I have an android app. I want to send POST request to a php file. The parameters consist of arrayList and Strings. I want to do something like this:

private Map<String, String> params;

    public RequestPostBook(long id, ArrayList<String> bookNames, ArrayList<String> bookAuthors, ArrayList<String> subjects,
                           String date,Response.Listener<String> listener)
    {
        super(Method.POST, REGISTER_REQUEST_URL, listener, null);


        params = new HashMap<>();
        params.put("candidateId", id + "");
        params.put("bookName",bookNames);
        params.put("authorName",bookAuthors);
        params.put("subjectName",subjects);
        params.put("reqDate",date);
    }

    @Override
    public Map<String, String> getParams() {
        return params;
    }

This is giving errors as the Map is (String, String).. Please help me about how to get it done. Please rectify this code. Thanks in advance.

Answer 1

The problem is that your Map is composed of <String,String> and you are passing an ArrayList<String> . You should do something like bookNames.toString() then you'll send a String

Or also you can create a JSONArray as follows :

JSONArray types=new JSONArray(Arrays.asList.(bookNames));

And then do the types.toString() and should work.

Then to decode it with PHP you should use json_decode function

$array = json_decode($json);

Answer 2

params is a Map<String, String> , so it can only take String as values. You are trying to put ArrayList s into it. What you might want to try is

JSONArray bookNamesJSON = new JSONArray(Arrays.asList(bookNames));
JSONArray bookAuthorsJSON = new JSONArray(Arrays.asList(bookAuthors));
JSONArray subjectsJSON = new JSONArray(Arrays.asList(subjects));

and then pass these objects to params

params.put("bookName",bookNamesJSON.toString());
params.put("authorName",bookAuthorsJSON.toString());
params.put("subjectName",subjectsJSON.toString());