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Using CORS with Vaadin
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<html> | |
<meta charset="UTF-8"> | |
<meta name="viewport" content="width=device-width, initial-scale=1.0"> | |
<head> | |
<!-- Add withCredentials to Vaadin requests to allow session cookies. Note: this affects to all XHRs on this page. --> | |
<script> | |
XMLHttpRequest.prototype._originalSend = XMLHttpRequest.prototype.send; | |
var sendWithCredentials = function(data) { | |
this.withCredentials = true; | |
this._originalSend(data); | |
}; | |
XMLHttpRequest.prototype.send = sendWithCredentials; | |
</script> | |
<style> | |
/* Set size and styles for the application DIV */ | |
#myapp { | |
width: 300px; | |
height: 300px; | |
border:1px solid #aaa; | |
box-shadow: 2px 2px 20px gray; | |
} | |
</style> | |
</head> | |
<body> | |
<!-- Load the Vaadin bootstrap --> | |
<script type="text/javascript" src="http://myvaadinappdomain.com/VAADIN/vaadinBootstrap.js"></script> | |
<!-- Placeholder for the vaadin application--> | |
<div id="myapp" class="v-app embedded"> | |
<div class="v-app-loading"></div> | |
</div> | |
<!-- Start the Vaadin application from myvaadinappdomain.com --> | |
<script type="text/javascript"> | |
window.onload= function() { | |
if (!window.vaadin) alert("Failed to load the Vaadin bootstrap"); | |
vaadin.initApplication("myapp", { | |
"browserDetailsUrl": "http://myvaadinappdomain.com/", | |
"serviceUrl": "http://myvaadinappdomain.com/", | |
"widgetset": "com.vaadin.DefaultWidgetSet", | |
"theme": "reindeer", | |
"versionInfo": {"vaadinVersion": null}, | |
"vaadinDir": "http://myvaadinappdomain.com/VAADIN/", | |
"heartbeatInterval": 300, | |
"debug": true, | |
}); | |
} | |
</script> | |
</body> | |
</html> |
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@WebServlet(value = "/*", asyncSupported = true) | |
@VaadinServletConfiguration(productionMode = false, ui = MyVaadinUI.class) | |
public static class MyCORSServlet extends VaadinServlet { | |
/** | |
* Override to handle the CORS requests. | |
*/ | |
@Override | |
protected void service(HttpServletRequest request, | |
HttpServletResponse response) throws ServletException, | |
IOException { | |
// Origin is needed for all CORS requests | |
String origin = request.getHeader("Origin"); | |
if (origin != null && isAllowedRequestOrigin(origin)) { | |
// Handle a preflight "option" requests | |
if ("options".equalsIgnoreCase(request.getMethod())) { | |
response.addHeader("Access-Control-Allow-Origin", origin); | |
response.setHeader("Allow", | |
"GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS"); | |
// allow the requested method | |
String method = request | |
.getHeader("Access-Control-Request-Method"); | |
response.addHeader("Access-Control-Allow-Methods", method); | |
// allow the requested headers | |
String headers = request | |
.getHeader("Access-Control-Request-Headers"); | |
response.addHeader("Access-Control-Allow-Headers", headers); | |
response.addHeader("Access-Control-Allow-Credentials", | |
"true"); | |
response.setContentType("text/plain"); | |
response.setCharacterEncoding("utf-8"); | |
response.getWriter().flush(); | |
return; | |
} // Handle UIDL post requests | |
else if ("post".equalsIgnoreCase(request.getMethod())) { | |
response.addHeader("Access-Control-Allow-Origin", origin); | |
response.addHeader("Access-Control-Allow-Credentials", | |
"true"); | |
super.service(request, response); | |
return; | |
} | |
} | |
// All the other requests nothing to do with CORS | |
super.service(request, response); | |
} | |
/** | |
* Check that the page Origin header is allowed. | |
*/ | |
private boolean isAllowedRequestOrigin(String origin) { | |
// TODO: Remember to limit the origins. | |
return origin.matches(".*"); | |
} | |
} |
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https://gist.github.com/elmot/ade1c6b31206e04184a5