Custom CORS filter in java

Implement CORS Filter in Java.

When you want to make a Cross Domain Call from angular.js to a Jboss (or Any server). You can write a simple servlet filter to achieve this.

Add a new Servlet like below

package com.rest.cors;

public class CorsFilter implements Filter {

    @Override

    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletResponse response = (HttpServletResponse) servletResponse;

        response.setHeader("Access-Control-Allow-Origin", "*");

        response.setHeader("Access-Control-Allow-Credentials", "true");

        response.setHeader("Access-Control-Allow-Methods", "POST, GET, HEAD, OPTIONS");

        response.setHeader("Access-Control-Allow-Headers", "Origin, Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");

        filterChain.doFilter(servletRequest, servletResponse);

    }

    @Override

    public void destroy() {

    }

}

Add a Filter entry in the web.xml of your war file

    <filter>

        <filter-name>cors</filter-name>

        <filter-class>com.rest.cors.CorsFilter</filter-class>

    </filter>

    <filter-mapping>

        <filter-name>cors</filter-name>

        <url-pattern>* /*</url-pattern>

    </filter-mapping>

This will ensure that CORS Filter applied to all, REST APIs and Servlets’.

Available headers are,

Access-Control-Allow-Origin – you can set the originating domain info here

Access-Control-Allow-Credentials – set to true by default

Access-Control-Expose-Headers

Access-Control-Max-Age

Access-Control-Allow-Methods

Access-Control-Allow-Headers

If you intend to use xml/json in content-type, please make sure you allow OPTION as in the above sample.