Jhipster Gateway empty response with code 200 when throwing com.netflix.zuul.exception.ZuulException: Forwarding error
<p>Using a microservice architecture sometimes I found communication errors between the gateway and the microservice, causing exceptions in the gateway like these:</p>

<pre><code>com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:15
....
Caused by: com.netflix.client.ClientException: null
    at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:123)
    at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:81)
    at org.springframework.cloud.netflix.zuul.filters.route.RestClientRibbonCommand.forward(RestClientRibbonCommand.java:135)
....
Caused by: java.net.URISyntaxException: Illegal character in query at index 69: http://192.168.4.25:8081/api/almacen/docs/1/metadata?metadatos=%5B%7B"clave":"cmis:name","valor":"documento.txt"%7D,%7B"clave":"cmis:lastModifiedBy","valor":"swagger"%7D%5D
    at java.net.URI$Parser.fail(URI.java:2848)
    at java.net.URI$Parser.checkChars(URI.java:3021)



com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:158)
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:133)
...
Caused by: com.netflix.client.ClientException: null
    at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:123)
    at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:81)
...
Caused by: java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
</code></pre>

<p>The problem is that the response from the gateway is 200 (OK) and empty content. I would like to have an error code, as I can see the error happens at the JWTFilter, when invoking the doFilter</p>

<pre><code>@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
    throws IOException, ServletException {
    try {
        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
        String jwt = resolveToken(httpServletRequest);
        if (StringUtils.hasText(jwt)) {
            if (this.tokenProvider.validateToken(jwt)) {
                Authentication authentication = this.tokenProvider.getAuthentication(jwt);
                SecurityContextHolder.getContext().setAuthentication(authentication);
            }
        }
        filterChain.doFilter(servletRequest, servletResponse);
    } catch (ExpiredJwtException eje) {
        log.info("Security exception for user {} - {}", eje.getClaims().getSubject(), eje.getMessage());
        ((HttpServletResponse) servletResponse).setStatus(HttpServletResponse.SC_UNAUTHORIZED);
    }
}
</code></pre>

<p>I try to catch the exception, even creating other filter that wraps the JWFilter, but I wasn't able to catch the error.</p>

<p>Is there any way to improve the code to get an error code instead a 200?</p>

<p>Thanks in advance</p>