java - Android，Volley Request，响应阻塞主线程

Question

使用 Volley 处理大型响应时发生了一些不好的事情:

String url = AppHelper.DOMAIN + "/service/pages/profile_update.json";

this.infoTextView.setText(getString(R.string.profile_info_updating));

final StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    JSONObject json = new JSONObject(response);

                    if (json.getBoolean("success")) {
                        // manage JSON object here
                    } else {
                        Toast.makeText(ProfileActivity.this,
                                getString(R.string.connection_problem_server),
                                Toast.LENGTH_LONG).show();
                    }
                } catch (JSONException e) {
                    ProfileActivity.this.infoTextView.setText(
                            getString(R.string.profile_info_updating_error));

                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
        ProfileActivity.this.infoTextView.setText(
                getString(R.string.profile_info_updating_error));

        if (error.networkResponse != null && error.networkResponse.statusCode == 401) {
            Toast.makeText(ProfileActivity.this,
                    getString(R.string.connection_problem_permission),
                    Toast.LENGTH_LONG).show();
        }

        new android.os.Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                if (ProfileActivity.this.swipeRefreshLayout != null) {
                    ProfileActivity.this.swipeRefreshLayout.setRefreshing(false);
                }
            }
        }, 1000);

        error.printStackTrace();
    }
}) {
    @Override
    protected Map<String, String> getParams() {
        Map<String, String> params = new HashMap<>();
        params.put("auth_token", ProfileActivity.this.defaultUser.getAuthenticationToken());
        return params;
    }

    @Override
    public Map<String, String> getHeaders() throws AuthFailureError {
        Map<String, String> params = new HashMap<>();
        params.putAll(super.getHeaders());
        params.put("Accept-Encoding", "gzip,deflate");
        return params;
    }

    @Override
    protected Response<String> parseNetworkResponse(NetworkResponse response) {
        StringBuilder output = new StringBuilder();
        try {
            GZIPInputStream gStream = new GZIPInputStream(new ByteArrayInputStream(response.data));
            InputStreamReader reader = new InputStreamReader(gStream);
            BufferedReader in = new BufferedReader(reader, 16384);

            String read;

            while ((read = in.readLine()) != null) {
                output.append(read).append("\n");
            }
            reader.close();
            in.close();
            gStream.close();
        } catch (IOException error) {
            error.printStackTrace();
            return Response.error(new ParseError());
        }

        return Response.success(output.toString(), HttpHeaderParser.parseCacheHeaders(response));
    }
};

stringRequest.setRetryPolicy(new RetryPolicy() {
    @Override
    public int getCurrentTimeout() {
        // 40 seconds
        return 40000;
    }

    @Override
    public int getCurrentRetryCount() {
        return DefaultRetryPolicy.DEFAULT_MAX_RETRIES;
    }

    @Override
    public void retry(VolleyError error) throws VolleyError {
        throw error;
    }
});

Volley.newRequestQueue(this).add(stringRequest);

此代码阻塞主线程，卡住应用程序。

此外，我设置了一些 header 值以允许 gzip 响应和处理数据的代码。但这不是造成不良行为的部分。应用程序仅在 onResponse(String response) 启动时卡住。

我该怎么做才能避免这种情况？

Answer 1

onResponse 和 onErrorResponse 是在 UI 线程上调用的，因此在这些方法中进行的任何繁重操作都会降低应用程序的响应速度。我猜您正在尝试解析 onResponse() 中的响应，这是不正确的。

You have to move to parsing logic to parseNetworkResponse since this is the method which is called in background thread. Refer the below link for more details :

https://developer.android.com/training/volley/request-custom.html