volley框架下,使用post方式请求服务器,传递参数和头

/**
     * volley框架下,使用post方式请求服务器,传递参数和头
     */
    public void postHead() {
        String url = "http://api.mefans.hk/token";
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        StringRequest request = new StringRequest(url, new Response.Listener() {

            @Override
            public void onResponse(String response) {
                Log.i("aa", "post请求成功" + response);
                Toast.makeText(MainActivity.this, response, Toast.LENGTH_LONG).show();

            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.i("aa", "post请求失败" + error.toString());
                Toast.makeText(MainActivity.this, error.toString(), Toast.LENGTH_LONG).show();

            }
        }) {
            @Override
            protected Map getParams() throws AuthFailureError {
                // 请求参数
                Map map = new HashMap();
                //new 一个Map  参数放到Map中
                map.put("grant_type", "client_credentials");
                return map;
            }

            @Override
            public Map getHeaders() throws AuthFailureError {
                // 请求头

                Map map = new HashMap();
//                map.put("Content-Type","application/x-www-form-urlencoded");
                map.put("Authorization ", "basic c6ed4f49ee14ce55554de3cecd1ef307066d8d5202a184f5d28e78df8815b25b");
                //new 一个Map这里设置头信息，把头信息放到Map中
                return map;
            }
        };
        request.setTag("request");
        requestQueue.add(request);
    }