Dropwizard Add a response filter for all resources

Question

How do I add a filter to my Dropwizard application that will check the response returned by each resource?

Should I use javax.servlet.Filterorjavax.ws.rs.container.ContainerResponseFilter

Any examples related to its use would be appreciated.

Answer 1

Add a response filter for all resources using dropwizard you can do the following:

• Create a CustomFilter that extends javax.servlet.Filter-

  public class CustomFilter implements Filter {
  
      public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
          // your filtering task
          chain.doFilter(req, res);
      }
  
      public void init(FilterConfig filterConfig) {
      }
  
      public void destroy() {
      }
  }
  

• Then register the same on your own Service, which extends Application-

  public class CustomService extends Application<CustomConfig> { //CustomConfig extend 'io.dropwizard.Configuration'
  
    public static void main(String[] args) throws Exception {
      new CustomService().run(args);
    }
  
    @Override
    public void initialize(Bootstrap<CustomConfig> someConfigBootstrap) {
      // do some initialization
    }
  
    @Override
    public void run(CustomConfig config, io.dropwizard.setup.Environment environment) throws Exception {
      ... // resource registration
      environment.servlets().addFilter("Custom-Filter", CustomFilter.class)
          .addMappingForUrlPatterns(java.util.EnumSet.allOf(javax.servlet.DispatcherType.class), true, "/*");
    }
  }
  

• Now you should well filter all the resources using the one described above CustomFilter.

Answer 2

I think you want to use javax.servlet.Filter.

A filter is an object that performs filtering tasks on either the request to a resource (a servlet or static content), or on the response from a resource, or both.

More details here .