UlmDesign JS Resource

A useful snippet HTML5 hybrid app for Android, using the method addJavascriptInterface to save and write file in external storage:

// write storage permission in your manifest file of Android project

    
    ...


// start code
@SuppressLint({"SetJavaScriptEnabled","JavascriptInterface"})
public class MainActivity extends Activity {
public WebView webView;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main); // source activity_main.xml
webView = (WebView) findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.addJavascriptInterface(new WebAppInterface(this), "Android");
webView.setWebViewClient(new WebViewClient());
// important set Web Chrome Client
webView.setWebChromeClient(new WebChromeClient());
webView.loadUrl(url); //local or remote
}
// final class for save and write file in external storage
final class WebAppInterface {
        Context mContext;

        /** Instantiate the interface and set the context */
        WebAppInterface(Context c) {
            mContext = c;
        }
        public void writeToFile(String data, String filename, String tag) {
            try {
                File root = android.os.Environment.getExternalStorageDirectory();
                File dir = new File (root.getAbsolutePath() + "/foldercustom");
                dir.mkdirs();
                File file = new File(dir, filename);
                FileOutputStream f = new FileOutputStream(file);
                PrintWriter pw = new PrintWriter(f);
                pw.println(data);
                pw.flush();
                pw.close();
                f.close();
            }
            catch (IOException e) {
                Log.e(tag, "File write failed: " + e.toString());
            }
        }
    }

}
// Now open html file in www folder




hello

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