Is there a way to call Java from JavaScript in Webview?

Use addJavascriptInterface() to add a Java object to the JavaScript environment of the WebView:

browser.addJavascriptInterface(new Locater(), "locater");

Your JavaScript can then reference methods on the fictitious object you injected:

<script language="javascript">
    function whereami() {
        var location=JSON.parse(locater.getLocation());

        document.getElementById("lat").innerHTML=location.lat;
        document.getElementById("lon").innerHTML=location.lon;
    }
</script>

where those methods are implemented on the Java object you used with addJavascriptInterface().

Here is a complete sample project from which these bits of code were pulled that demonstrates this.