how can i add a custom header to post request on webview

Question

I am now having a problem about post request on webview. Here is the situation: when my webview loaded a login page,and there's a form inside which would make the post request.How can i add a custom header to it when i click submit button.

Answer 1

I ran into needing to implement such a feature myself so I'm posting a code snippet for anyone running into the same issue in the future. I'd definitely recommend using OkHttp but the principle (make a request and load the html into the browser in the success callback) should be the same with any other network client.

protected void postURL(final String url, String postData) {
    Request request = new Request.Builder()
            .url(url)
            .addHeader("Cache-Control", "max-age=0")
            .addHeader("Origin", "null") //Optional
            .addHeader("Upgrade-Insecure-Requests", "1")
            .addHeader("User-Agent", webView.getSettings().getUserAgentString())
            .addHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8")
            .addHeader("Accept-Language", Locale.getDefault().getLanguage())
            .addHeader("Cookie", CookieManager.getInstance().getCookie(url))
            .addHeader("X-Requested-With", BuildConfig.APPLICATION_ID)
            .post(RequestBody.create(MediaType.parse("application/x-www-form-urlencoded"), postData))
            .build();

    new OkHttpClient().newCall(request).enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            Timber.e(e.getMessage());
        }

        @Override
        public void onResponse(Call call, final Response response) throws IOException {
            final String htmlString = response.body().string();

            webView.post(new Runnable() {
                @Override
                public void run() {
                    webView.clearCache(true);
                    webView.loadDataWithBaseURL(url, htmlString, "text/html", "utf-8", null);
                }
            });
        }
    });
}

Note that most of those headers are not required but can be used as a guideline to reconstruct an original request issued by the webview itself