android - 使用 header 调用 Volley 请求时出现 UnsupportedOperationException

Question

我尝试使用 Volley 库发出调用请求。我想设置 header ，但出现 java.lang.UnsupportedOperationException。您知道为什么吗？我该如何解决这个问题？

 public void getAccountInfo() {
            RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
            String url = "http://demo.gopos.pl/oauth/token";
            StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
                    new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            // Display the first 500 characters of the response string.
                            Log.e(TAG, "onResponse SUCCES!!" + response);

                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, "That didn't work!");
            }

        }) {
            @Override
            public Map<String,String> getHeaders()throws AuthFailureError {
                Map<String,String> params = super.getHeaders();
                if(params==null)params = new HashMap<>();
                params.put("username","username");
                params.put("password","password");
                return params;
            }
        };
        queue.add(stringRequest);


    }

Answer 1

删除这两行:

 Map<String,String> params = super.getHeaders();
            if(params==null)params = new HashMap<>();

然后添加这个:

   Map<String, String> params = new HashMap<>();

它现在应该可以工作了。