JsonObjectRequest -无法发送参数

JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, url, null,
        new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                // 处理响应
            }
        },
        new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                // 处理错误
            }
        }) {
    @Override
    protected Map<String, String> getParams() {
        Map<String, String> params = new HashMap<>();
        params.put("param1", "value1");
        params.put("param2", "value2");
        return params;
    }
};

RequestQueue queue = Volley.newRequestQueue(context);
queue.add(request);