Android Calling JavaScript functions in WebView -

i trying call javascript functions sitting in html page running inside android webview. pretty simple code tries below - android app, call javascript function test message, inturn calls java function in android app displays test message via toast.

the javascript function looks like:

function testecho(message){      window.jsinterface.doechotest(message); } 

from webview, have tried calling javascript following ways no luck:

mywebview.loadurl("javascript:testecho(hello world!)"); mwebview.loadurl("javascript:(function () { " + "testecho(hello world!);" + "})()"); 

i did enable javascript on webview

mywebview.getsettings().setjavascriptenabled(true); // register class containing methods exposed javascript mywebview.addjavascriptinterface(myjsinterface, "jsinterface");  

and heres java class

public class jsinterface{  private webview mappview; public jsinterface  (webview appview) {         this.mappview = appview;     }      public void doechotest(string echo){         toast toast = toast.maketext(mappview.getcontext(), echo, toast.length_short);         toast.show();     } } 

i've spent lot of time googling around see may doing wrong. examples have found use approach. see wrong here?

edit: there several other external javascript files being referenced & used in html, issue?

i figured out issue : missing quotes in testecho() parameter. how got call work:

mywebview.loadurl("javascript:testecho('hello world!')");