calling java function from javascript on android

Question

I'm trying to make connection between javascript and java in android app and i'm able to control javascript in a way that it fills "gsm_num" field with 111111 and later with 222222 but it cannot call a function "jsmessage" in java...i tried moving @SuppressLint("JavascriptInterface") before whole on click function but it just can't print js message... can someone please show me what am i doing wrong?

@Override
        public void onClick(View arg0) {

            String url = "http://www.page.com";
            wv.loadUrl(url);
            setContentView(wv);
            wv.getSettings().setJavaScriptEnabled(true);
            wv.setWebViewClient(new WebViewClient() {

                public void onPageFinished(WebView view1, String url) {

                    view1.getSettings().setJavaScriptEnabled(true);
                    view1.loadUrl("javascript: document.getElementById('gsm_num').value = '11111111'; document.forms['button'].submit();");

                    view1.setWebViewClient(new WebViewClient() {
                        @SuppressLint("JavascriptInterface")
                        @JavascriptInterface
                        public void onPageFinished(WebView view2, String url) {

                            final class JavaScriptInterface {
                                JavaScriptInterface () { }
                                public void jsmessage() {
                                    Log.e("btijs", "message");
                                }
                              }


                            view2.getSettings().setJavaScriptEnabled(true);

                            view2.addJavascriptInterface(new JavaScriptInterface(), "JSInterface");
                            view1.loadUrl("javascript: document.getElementById('gsm_num2').value = '2222222'; window.JSInterface.jsmessage();");


                         }

                    });
                }
            });
        }
    });

Answer 1

I think there are a couple problems here. First I think you need to add a new JavaScriptInterface to your WebView like this:

    wv.addJavascriptInterface(new MyJavaScriptInterface(), "HTMLOUT");

And I think your JavaScript code itself might not work. You're not actually declaring your input as a function. Here's some code I used to do a similar task:

    wv.loadUrl("javascript:(function() { " +
                        "window.HTMLOUT.showHTML(document.getElementById('role').innerHTML);" +
                        "})()");

Where showHTML is a method I wrote inside the JavaScriptInterface

Here is my JavaScriptInterface class inside of the method where I'm using it:

private void Authentication(){

    class MyJavaScriptInterface {

        @JavascriptInterface
        public void showHTML(String content) {
            // grants access based on authorization level

            }
        }
    }

    // open up the login page
    final WebView wv = (WebView)findViewById(R.id.login_webview);

    wv.getSettings().setJavaScriptEnabled(true);

    wv.addJavascriptInterface(new MyJavaScriptInterface(), "HTMLOUT");

    wv.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url) {

            //once page is finished loading, check id="role" pass that value to showHTML
            if(url.contains(getString(R.string.loginURL))) {
                wv.loadUrl("javascript:(function() { " +
                        "window.HTMLOUT.showHTML(document.getElementById('role').innerHTML);" +
                        "})()");

            }

        }

        @Override
        public void onReceivedError(WebView view, int errorCode, String description,
                                    String failingUrl) {
            Log.w("LoginActivity: ", description);
        }
    });

    wv.loadUrl(getString(R.string.loginURL));

}