Java EE过滤器优先级控制的实例解读

@Priority(1)
@Provider
public class TimeFilter implements ContainerRequestFilter, ContainerResponseFilter {
    @Override
    public void filter(ContainerRequestContext reqContext) throws IOException {
        System.out.println("-- TimeFilter request --");
        reqContext.setProperty("start-time", System.currentTimeMillis());
    }
    @Override
    public void filter(ContainerRequestContext reqContext,
                       ContainerResponseContext resContext) throws IOException {
        System.out.println("-- TimeFilter response --");
        long startTime = (long) reqContext.getProperty("start-time");
        System.out.printf("Time taken for request %s:  %s milli secs%n",
                reqContext.getUriInfo().getPath(),
                System.currentTimeMillis() - startTime
        );
    }
}

@Priority(2)
@Provider
public class LogFilter implements ContainerRequestFilter, ContainerResponseFilter {
    @Override
    public void filter(ContainerRequestContext reqContext) throws IOException {
        System.out.println("-- req headers --");
        log(reqContext.getUriInfo(), reqContext.getHeaders());
    }
    @Override
    public void filter(ContainerRequestContext reqContext,
                       ContainerResponseContext resContext) throws IOException {
        System.out.println("-- res headers --");
        log(reqContext.getUriInfo(), resContext.getHeaders());
    }
    private void log(UriInfo uriInfo, MultivaluedMap<String, ?> headers) {
        System.out.println("Path: " + uriInfo.getPath());
        headers.entrySet().forEach(h -> System.out.println(h.getKey() + ": " + h.getValue()));
    }
}

@Path("/")
public class MyResource {
    @GET
    @Path("{path:.*}")
    public String getResponse(@PathParam("path") String path) {
        System.out.printf("creating response for '%s'%n", path);
        return "dummy-response for " + path;
    }
}

mvn tomcat7:run-war