[rest] No 'Access-Control-Allow-Origin' header is present on the requested resource - Resteasy

I am working on a webapplication comprises UI-Angular , Server-Java , RestEasy 3.0.9.Final for rest api calls

When i tried to access the rest service from another domain am getting below error

CANNOT LOAD Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8080' is therefore not allowed access.

I configured my server side to respond with the cross domain calls and this is working with the GET Call but POST Call is creating ERROR

web.xml

<context-param>
    <param-name>resteasy.providers</param-name>
    <param-value>com.test.sample.app.CorsFeature</param-value>
</context-param>

<listener>
    <listener-class>
        org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
</listener>


<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<servlet>
    <servlet-name>resteasy-servlet</servlet-name>
    <servlet-class>
        org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
    <init-param>
        <param-name>javax.ws.rs.Application</param-name>
        <param-value>com.test.sample.app.Application</param-value>
    </init-param>
</servlet>

<servlet-mapping>
    <servlet-name>resteasy-servlet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>

<context-param>
    <param-name>resteasy.servlet.mapping.prefix</param-name>
    <param-value>/rest</param-value>
</context-param>
<context-param>
    <param-name>resteasy.scan</param-name>
    <param-value>true</param-value>
</context-param>

Service class

@GET
@Path("/getnameAtt")
@Produces(MediaType.APPLICATION_JSON)
public Response getHostnameAttributes() {
return Response
.status(200)
.header("Access-Control-Allow-Origin", "*")
.header("Access-Control-Allow-Headers",
        "origin, content-type, accept, authorization")
.header("Access-Control-Allow-Credentials", "true")
.header("Access-Control-Allow-Methods",
        "GET, POST, PUT, DELETE, OPTIONS, HEAD")
.header("Access-Control-Max-Age", "1209600")
.entity(new TestImpl().getHostNameAttributes())
.build();
}

@POST
@Path("/getSeq")
@Produces(MediaType.APPLICATION_JSON)
public Response getCurrentSequence(String request) {
return Response
.status(200)
.header("Access-Control-Allow-Origin", "*")
.header("Access-Control-Allow-Headers",
        "origin, content-type, accept, authorization")
.header("Access-Control-Allow-Credentials", "true")
.header("Access-Control-Allow-Methods",
        "GET, POST, PUT, DELETE, OPTIONS, HEAD")
.header("Access-Control-Max-Age", "1209600")
.entity(new TestImpl().getCurrentSeq(request))
.build();
}

Since i am new to resteasy not able to figure out why this was not working. Any help would be greatly appreciated . Waiting for your response.

Thanks

After facing a similar issue, below is what I did :

• Created a class extending javax.ws.rs.core.Application and added a Cors Filter to it.

To the CORS filter, I added corsFilter.getAllowedOrigins().add("http://localhost:4200");.

Basically, you should add the URL which you want to allow Cross-Origin Resource Sharing. Ans you can also use "*" instead of any specific URL to allow any URL.

public class RestApplication
    extends Application
{
    private Set<Object> singletons = new HashSet<Object>();

    public MessageApplication()
    {
        singletons.add(new CalculatorService()); //CalculatorService is your specific service you want to add/use.
        CorsFilter corsFilter = new CorsFilter();
        // To allow all origins for CORS add following, otherwise add only specific urls.
        // corsFilter.getAllowedOrigins().add("*");
        System.out.println("To only allow restrcited urls ");
        corsFilter.getAllowedOrigins().add("http://localhost:4200");
        singletons = new LinkedHashSet<Object>();
        singletons.add(corsFilter);
    }

    @Override
    public Set<Object> getSingletons()
    {
        return singletons;
    }
}

• And here is my web.xml:

<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>Restful Web Application</display-name>

    <!-- Auto scan rest service -->
    <context-param>
        <param-name>resteasy.scan</param-name>
        <param-value>true</param-value>
    </context-param>

    <context-param>
        <param-name>resteasy.servlet.mapping.prefix</param-name>
        <param-value>/rest</param-value>
    </context-param>

    <listener>
        <listener-class>
            org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap
        </listener-class>
    </listener>

    <servlet>
        <servlet-name>resteasy-servlet</servlet-name>
        <servlet-class>
            org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
        </servlet-class>
        <init-param>
            <param-name>javax.ws.rs.Application</param-name>
            <param-value>com.app.RestApplication</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>resteasy-servlet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

</web-app>

The most important code which I was missing when I was getting this issue was, I was not adding my class extending javax.ws.rs.Application i.e RestApplication to the init-param of <servlet-name>resteasy-servlet</servlet-name>

   <init-param>
        <param-name>javax.ws.rs.Application</param-name>
        <param-value>com.app.RestApplication</param-value>
    </init-param>

And therefore my Filter was not able to execute and thus the application was not allowing CORS from the URL specified.

Seems your resource POSTmethod won't get hit as @peeskillet mention. Most probably your ~POST~ request won't work, because it may not be a simple request. The only simple requests are GET, HEAD or POST and request headers are simple(The only simple headers are Accept, Accept-Language, Content-Language, Content-Type= application/x-www-form-urlencoded, multipart/form-data, text/plain).

Since in you already add Access-Control-Allow-Origin headers to your Response, you can add new OPTIONS method to your resource class.

    @OPTIONS
@Path("{path : .*}")
public Response options() {
    return Response.ok("")
            .header("Access-Control-Allow-Origin", "*")
            .header("Access-Control-Allow-Headers", "origin, content-type, accept, authorization")
            .header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD")
            .header("Access-Control-Max-Age", "2000")
            .build();
}