A possible cause of "...has been blocked by CORS policy"

A JavaScript client:


const deletePing = async () => {
    const config = {
        method: "delete"
    };
    const response = await fetch('http://localhost:8080/cors-error-delete/resources/ping/duke', config);
    console.log(response.status);
};
deletePing();

reports the following error:
app.js:6 OPTIONS http://localhost:8080/cors-error-delete/resources/ping/duke and Access to fetch at 'http://localhost:8080/cors-error-delete/resources/ping/duke' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status.
when a preflight request automatically initiated by the browser fails with status 404.

This will happen, if a resource like:


import javax.ws.rs.DELETE;
import javax.ws.rs.Path;

@Path("ping")
public class PingResource {

    @DELETE
    public void remove() {
    }
}

exposed with:

@ApplicationPath("resources")
public class JAXRSConfiguration extends Application {}    
and with installed CORS-filter:

<dependency>
    <groupId>com.airhacks</groupId>
    <artifactId>jaxrs-cors</artifactId>
    <version>0.0.2</version>
</dependency>    

doesn't accept path params, but the JavaScript client passes them.

In our case: DELETE http://localhost:8080/cors-error-delete/resources/ping/duke is requested, but only http://localhost:8080/cors-error-delete/resources/ping/ is offered.

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