Spring Rest API interceptor add response header on each/every request - rest

Question

I am working with Spring 4 REST API annotation based configuration application. I want to add response header on each/every request once user is authenticate by JWT. I have created interceptor for that which looks as below:
public class AuthenticateInterceptor implements HandlerInterceptor {
#Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object, Exception arg3)
throws Exception {
response.addHeader("afterCompletion", "afterCompletion header");
response.setHeader("afterCompletion", "afterCompletion header");
System.out.println("************** afterCompletion **************");
}
#Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object,
ModelAndView modelAndView) throws Exception {
response.addHeader("postHandle", "postHandle header");
System.out.println("************** postHandle **************");
}
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {
System.out.println("************** preHandle **************");
return true;
}
}
My interceptor configuration is as below:
#Configuration
public class AdapterConfig extends WebMvcConfigurerAdapter {
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new AuthenticateInterceptor());
}
}
When I get JSON response I am not able the see the added header value which are added from interceptor. Any one help me what is the issue and how can I add header from interceptor for each/every request.

Answer 1

I didn't succeed in interceptors, Instead using Filters or WebFilter perfectly works:
#Component
public class ResponseHeaderWebFilter implements Filter {
#Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletResponse httpServletResponse = (HttpServletResponse) response;
httpServletResponse.setHeader("CustomHeaderName", "SomeValue");
chain.doFilter(request, response);
}
}
In case you are using webflux reactive component, then :
#Component
public class ResponseHeaderWebFilter implements WebFilter {
#Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
exchange.getResponse()
.getHeaders()
.add("CustomHeaderName", "SomeValue");
return chain.filter(exchange);
}
}

Answer 2

If it can help you, I've managed it like this: https://stackoverflow.com/a/49431665/4939245
Look at second point
You can put the response header for each call in the application (this is for Spring annotation-based):
#Component
public class Filter extends OncePerRequestFilter {
....
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
//response.addHeader("Access-Control-Allow-Origin", "*");
//response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
response.setHeader("Cache-Control", "no-store"); // HTTP 1.1.
response.setHeader("Pragma", "no-cache"); // HTTP 1.0.
response.setHeader("Expires", "0"); // Proxies.
filterChain.doFilter(request, response);
}
}
I hope I was helpful!

Answer 3

You are almost doing same but would like to give you consitant way of achieving same. Please do following changes.
1) Add #Component annotation on AuthenticateInterceptor class. And you package containing this class should be in packages scanned list.
#Component
public class AuthenticateInterceptor implements HandlerInterceptor {
...
}
2) Autowire and inject instance of AuthenticateInterceptor like below.
#Configuration
public class AdapterConfig extends WebMvcConfigurerAdapter {
#Autowired
private AuthenticateInterceptor authenticateInterceptor;
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(authenticateInterceptor);
}
}