9. Developer Guide

TODO: document writing Custom Route Predicate Factories

In order to write a GatewayFilter you will need to implement GatewayFilterFactory. There is an abstract class called AbstractGatewayFilterFactory which you can extend.

PreGatewayFilterFactory.java. 

---
public class PreGatewayFilterFactory extends AbstractGatewayFilterFactory<PreGatewayFilterFactory.Config> {

public PreGatewayFilterFactory() {
	super(Config.class);
}

@Override
public GatewayFilter apply(Config config) {
	// grab configuration from Config object
	return (exchange, chain) -> {
           //If you want to build a "pre" filter you need to manipulate the
           //request before calling change.filter
           ServerHttpRequest.Builder builder = exchange.getRequest().mutate();
           //use builder to manipulate the request
           return chain.filter(exchange.mutate().request(request).build());
	};
}

public static class Config {
       //Put the configuration properties for your filter here
}

}

PostGatewayFilterFactory.java. 

---
public class PostGatewayFilterFactory extends AbstractGatewayFilterFactory<PostGatewayFilterFactory.Config> {

public PostGatewayFilterFactory() {
	super(Config.class);
}

@Override
public GatewayFilter apply(Config config) {
	// grab configuration from Config object
	return (exchange, chain) -> {
		return chain.filter(exchange).then(Mono.fromRunnable(() -> {
			ServerHttpReponse response = exchange.getResponse();
			//Manipulate the response in some way
		}));
	};
}

public static class Config {
       //Put the configuration properties for your filter here
}

}

TODO: document writing Custom Global Filters

TODO: document writing Custom Route Locators and Writers