package io.vertx.blueprint.todolist.common;
import io.reactivex.Completable;
import io.reactivex.Maybe;
import io.reactivex.Single;
import io.vertx.core.http.HttpMethod;
import io.vertx.core.json.JsonObject;
import io.vertx.reactivex.core.AbstractVerticle;
import io.vertx.reactivex.core.http.HttpServerResponse;
import io.vertx.reactivex.ext.web.Router;
import io.vertx.reactivex.ext.web.RoutingContext;
import io.vertx.reactivex.ext.web.handler.CorsHandler;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.function.Function;
/**
* An abstract base reactive verticle that provides several helper methods for RESTful API.
*
* @author <a href="http://www.sczyh30.com">Eric Zhao</a>
*/
public abstract class RestfulApiVerticle extends AbstractVerticle {
/**
* Create an HTTP server for the REST service.
*
* @param router router instance
* @param host server host
* @param port server port
* @return asynchronous result
*/
protected Completable createHttpServer(Router router, String host, int port) {
return vertx.createHttpServer()
.requestHandler(router::accept)
.rxListen(port, host)
.toCompletable();
}
/**
* Enable CORS support for web router.
*
* @param router router instance
*/
protected void enableCorsSupport(Router router) {
Set<String> allowHeaders = new HashSet<>();
allowHeaders.add("x-requested-with");
allowHeaders.add("Access-Control-Allow-Origin");
allowHeaders.add("origin");
allowHeaders.add("Content-Type");
allowHeaders.add("accept");
// CORS support
router.route().handler(CorsHandler.create("*")
.allowedHeaders(allowHeaders)
.allowedMethod(HttpMethod.GET)
.allowedMethod(HttpMethod.POST)
.allowedMethod(HttpMethod.DELETE)
.allowedMethod(HttpMethod.PATCH)
.allowedMethod(HttpMethod.PUT)
);
}
// Helper status methods.
/**
* Resolve an asynchronous status and send back the response.
* By default, the successful status code is 200 OK.
*
* @param context routing context
* @param asyncResult asynchronous status with no result
*/
protected void sendResponse(RoutingContext context, Completable asyncResult) {
HttpServerResponse response = context.response();
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
asyncResult.subscribe(response::end, ex -> internalError(context, ex));
}
}
/**
* Resolve an asynchronous status and send back the response.
* The successful status code depends on processor {@code f}.
*
* @param context routing context
* @param asyncResult asynchronous status with no result
*/
protected void sendResponse(RoutingContext context, Completable asyncResult, Consumer<RoutingContext> f) {
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
asyncResult.subscribe(() -> f.accept(context), ex -> internalError(context, ex));
}
}
protected <T> void sendResponse(RoutingContext context, Single<T> asyncResult,
Function<T, String> converter, BiConsumer<RoutingContext, String> f) {
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
asyncResult.subscribe(r -> f.accept(context, converter.apply(r)), ex -> internalError(context, ex));
}
}
/**
* Resolve an asynchronous result and send back the response.
*
* @param context routing context
* @param asyncResult asynchronous result
* @param converter result content converter
* @param <T> the type of result
*/
protected <T> void sendResponse(RoutingContext context, Single<T> asyncResult, Function<T, String> converter) {
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
asyncResult.subscribe(r -> ok(context, converter.apply(r)),
ex -> internalError(context, ex));
}
}
protected <T> void sendResponse(RoutingContext context, Maybe<T> asyncResult, Function<T, String> converter) {
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
Single<Optional<T>> single = asyncResult.map(Optional::of)
.switchIfEmpty(Maybe.just(Optional.empty()))
.toSingle();
sendResponseOpt(context, single, converter);
}
}
protected <T> void sendResponseOpt(RoutingContext context, Single<Optional<T>> asyncResult, Function<T, String> converter) {
if (asyncResult == null) {
internalError(context, "invalid_status");
} else {
asyncResult.subscribe(r -> {
if (r.isPresent()) {
ok(context, converter.apply(r.get()));
} else {
notFound(context);
}
},
ex -> internalError(context, ex));
}
}
/**
* Send back a response with status 200 Ok.
*
* @param context routing context
*/
protected void ok(RoutingContext context) {
context.response().end();
}
/**
* Send back a response with status 200 OK.
*
* @param context routing context
* @param content body content in JSON format
*/
protected void ok(RoutingContext context, String content) {
context.response().setStatusCode(200)
.putHeader("content-type", "application/json")
.end(content);
}
/**
* Send back a response with status 201 Created.
*
* @param context routing context
*/
protected void created(RoutingContext context) {
context.response().setStatusCode(201).end();
}
/**
* Send back a response with status 201 Created.
*
* @param context routing context
* @param content body content in JSON format
*/
protected void created(RoutingContext context, String content) {
context.response().setStatusCode(201)
.putHeader("content-type", "application/json")
.end(content);
}
/**
* Send back a response with status 204 No Content.
*
* @param context routing context
*/
protected void noContent(RoutingContext context) {
context.response().setStatusCode(204).end();
}
/**
* Send back a response with status 400 Bad Request.
*
* @param context routing context
* @param ex exception
*/
protected void badRequest(RoutingContext context, Throwable ex) {
context.response().setStatusCode(400)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", ex.getMessage()).encodePrettily());
}
/**
* Send back a response with status 400 Bad Request.
*
* @param context routing context
*/
protected void badRequest(RoutingContext context) {
context.response().setStatusCode(400)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", "bad_request").encodePrettily());
}
/**
* Send back a response with status 404 Not Found.
*
* @param context routing context
*/
protected void notFound(RoutingContext context) {
context.response().setStatusCode(404)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("message", "not_found").encodePrettily());
}
/**
* Send back a response with status 500 Internal Error.
*
* @param context routing context
* @param ex exception
*/
protected void internalError(RoutingContext context, Throwable ex) {
context.response().setStatusCode(500)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", ex.getMessage()).encodePrettily());
}
/**
* Send back a response with status 500 Internal Error.
*
* @param context routing context
* @param cause error message
*/
protected void internalError(RoutingContext context, String cause) {
context.response().setStatusCode(500)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", cause).encodePrettily());
}
/**
* Send back a response with status 503 Service Unavailable.
*
* @param context routing context
*/
protected void serviceUnavailable(RoutingContext context) {
context.fail(503);
}
/**
* Send back a response with status 503 Service Unavailable.
*
* @param context routing context
* @param ex exception
*/
protected void serviceUnavailable(RoutingContext context, Throwable ex) {
context.response().setStatusCode(503)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", ex.getMessage()).encodePrettily());
}
/**
* Send back a response with status 503 Service Unavailable.
*
* @param context routing context
* @param cause error message
*/
protected void serviceUnavailable(RoutingContext context, String cause) {
context.response().setStatusCode(503)
.putHeader("content-type", "application/json")
.end(new JsonObject().put("error", cause).encodePrettily());
}
}
