/*
 * Copyright 2014 Red Hat, Inc.
 *
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse License v1.0
 *  and Apache License v2.0 which accompanies this distribution.
 *
 *  The Eclipse License is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 *
 *  The Apache License v2.0 is available at
 *  http://www.opensource.org/licenses/apache2.0.php
 *
 *  You may elect to redistribute this code under either of these licenses.
 */

package io.vertx.ext.web;

import io.vertx.codegen.annotations.*;
import io.vertx.core.Handler;
import io.vertx.core.MultiMap;
import io.vertx.core.Vertx;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.http.HttpMethod;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.core.http.HttpServerResponse;
import io.vertx.core.json.JsonArray;
import io.vertx.core.json.JsonObject;
import io.vertx.ext.auth.User;

import java.util.List;
import java.util.Map;
import java.util.Set;

Represents the context for the handling of a request in Vert.x-Web.
 A new instance is created for each HTTP request that is received in the Handler<HttpServerRequest>.handle(HttpServerRequest) of the router. 

The same instance is passed to any matching request or failure handlers during the routing of the request or
failure.
 The context provides access to the HttpServerRequest and HttpServerResponse and allows you to maintain arbitrary data that lives for the lifetime of the context. Contexts are discarded once they have been routed to the handler for the request. 
 The context also provides access to the Session, cookies and body for the request, given the correct handlers in the application. 

If you use the internal error handler
Author:
Tim Fox/**
 * Represents the context for the handling of a request in Vert.x-Web.
 * <p>
 * A new instance is created for each HTTP request that is received in the
 * {@link Router#handle(HttpServerRequest)} of the router.
 * <p>
 * The same instance is passed to any matching request or failure handlers during the routing of the request or
 * failure.
 * <p>
 * The context provides access to the {@link HttpServerRequest} and {@link HttpServerResponse}
 * and allows you to maintain arbitrary data that lives for the lifetime of the context. Contexts are discarded once they
 * have been routed to the handler for the request.
 * <p>
 * The context also provides access to the {@link Session}, cookies and body for the request, given the correct handlers
 * in the application.
 * <p>
 * If you use the internal error handler
 *
 * @author <a href="http://tfox.org">Tim Fox</a>
 */
@VertxGen
public interface RoutingContext {

  
Returns:
the HTTP request object/**
   * @return the HTTP request object
   */
  @CacheReturn
  HttpServerRequest request();

  
Returns:
the HTTP response object/**
   * @return the HTTP response object
   */
  @CacheReturn
  HttpServerResponse response();

  
Tell the router to route this context to the next matching route (if any).
This method, if called, does not need to be called during the execution of the handler, it can be called
some arbitrary time later, if required.

If next is not called for a handler then the handler should make sure it ends the response or no response
will be sent.
/**
   * Tell the router to route this context to the next matching route (if any).
   * This method, if called, does not need to be called during the execution of the handler, it can be called
   * some arbitrary time later, if required.
   * <p>
   * If next is not called for a handler then the handler should make sure it ends the response or no response
   * will be sent.
   */
  void next();

  
Fail the context with the specified status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with provided status code. 
Params:
statusCode –  the HTTP status code/**
   * Fail the context with the specified status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with provided status code.
   *
   * @param statusCode  the HTTP status code
   */
  void fail(int statusCode);

  
Fail the context with the specified throwable and 500 status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with 500 status code. 
Params:
throwable –  a throwable representing the failure/**
   * Fail the context with the specified throwable and 500 status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with 500 status code.
   *
   * @param throwable  a throwable representing the failure
   */
  void fail(Throwable throwable);

  
Fail the context with the specified throwable and the specified the status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with provided status code. 
Params:
statusCode – the HTTP status code
throwable – a throwable representing the failure/**
   * Fail the context with the specified throwable and the specified the status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with provided status code.
   *
   * @param statusCode the HTTP status code
   * @param throwable a throwable representing the failure
   */
  void fail(int statusCode, Throwable throwable);

  
Put some arbitrary data in the context. This will be available in any handlers that receive the context.
Params:
key –  the key for the data
obj –  the data
Returns:
a reference to this, so the API can be used fluently/**
   * Put some arbitrary data in the context. This will be available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param obj  the data
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  RoutingContext put(String key, Object obj);

  
Get some data from the context. The data is available in any handlers that receive the context.
Params:
key –  the key for the data
Type parameters:
<T> –  the type of the data
Throws:
ClassCastException – if the data is not of the expected type
Returns:
 the data/**
   * Get some data from the context. The data is available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param <T>  the type of the data
   * @return  the data
   * @throws ClassCastException if the data is not of the expected type
   */
  <T> T get(String key);

  
Remove some data from the context. The data is available in any handlers that receive the context.
Params:
key –  the key for the data
Type parameters:
<T> –  the type of the data
Throws:
ClassCastException – if the data is not of the expected type
Returns:
 the previous data associated with the key/**
   * Remove some data from the context. The data is available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param <T>  the type of the data
   * @return  the previous data associated with the key
   * @throws ClassCastException if the data is not of the expected type
   */
  <T> T remove(String key);

  
Returns:
all the context data as a map/**
   * @return all the context data as a map
   */
  @GenIgnore(GenIgnore.PERMITTED_TYPE)
  Map<String, Object> data();

  
Returns:
the Vert.x instance associated to the initiating Router for this context/**
   * @return the Vert.x instance associated to the initiating {@link Router} for this context
   */
  @CacheReturn
  Vertx vertx();

  
Returns:
the mount point for this router. It will be null for a top level router. For a sub-router it will be the path
at which the subrouter was mounted./**
   * @return the mount point for this router. It will be null for a top level router. For a sub-router it will be the path
   * at which the subrouter was mounted.
   */
  @Nullable String mountPoint();

  
Returns:
the current route this context is being routed through./**
   * @return the current route this context is being routed through.
   */
  Route currentRoute();

  
Return the normalised path for the request.

The normalised path is where the URI path has been decoded, i.e. any unicode or other illegal URL characters that
were encoded in the original URL with `%` will be returned to their original form. E.g. `%20` will revert to a space.
Also `+` reverts to a space in a query.

The normalised path will also not contain any `..` character sequences to prevent resources being accessed outside
of the permitted area.
 It's recommended to always use the normalised path as opposed to HttpServerRequest.path() if accessing server resources requested by a client. 
Returns:
the normalised path/**
   * Return the normalised path for the request.
   * <p>
   * The normalised path is where the URI path has been decoded, i.e. any unicode or other illegal URL characters that
   * were encoded in the original URL with `%` will be returned to their original form. E.g. `%20` will revert to a space.
   * Also `+` reverts to a space in a query.
   * <p>
   * The normalised path will also not contain any `..` character sequences to prevent resources being accessed outside
   * of the permitted area.
   * <p>
   * It's recommended to always use the normalised path as opposed to {@link HttpServerRequest#path()}
   * if accessing server resources requested by a client.
   *
   * @return the normalised path
   */
  String normalisedPath();

  
Get the cookie with the specified name. The context must have first been routed to a CookieHandler for this to work. 
Params:
name –  the cookie name
Returns:
the cookie/**
   * Get the cookie with the specified name. The context must have first been routed to a {@link io.vertx.ext.web.handler.CookieHandler}
   * for this to work.
   *
   * @param name  the cookie name
   * @return the cookie
   */
  @Nullable Cookie getCookie(String name);

  
Add a cookie. This will be sent back to the client in the response. The context must have first been routed to a CookieHandler for this to work. 
Params:
cookie –  the cookie
Returns:
a reference to this, so the API can be used fluently/**
   * Add a cookie. This will be sent back to the client in the response. The context must have first been routed
   * to a {@link io.vertx.ext.web.handler.CookieHandler} for this to work.
   *
   * @param cookie  the cookie
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  RoutingContext addCookie(Cookie cookie);

  
Expire a cookie, notifying a User Agent to remove it from its cookie jar. The context must have first been routed to a CookieHandler for this to work. 
Params:
name –  the name of the cookie
Returns:
the cookie, if it existed, or null/**
   * Expire a cookie, notifying a User Agent to remove it from its cookie jar. The context must have first been routed
   * to a {@link io.vertx.ext.web.handler.CookieHandler} for this to work.
   *
   * @param name  the name of the cookie
   * @return the cookie, if it existed, or null
   */
  default @Nullable Cookie removeCookie(String name) {
    return removeCookie(name, true);
  }

  
Remove a cookie from the cookie set. If invalidate is true then it will expire a cookie, notifying a User Agent to remove it from its cookie jar. The context must have first been routed to a CookieHandler for this to work. 
Params:
name –  the name of the cookie
Returns:
the cookie, if it existed, or null/**
   * Remove a cookie from the cookie set. If invalidate is true then it will expire a cookie, notifying a User Agent to
   * remove it from its cookie jar. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.CookieHandler} for this to work.
   *
   * @param name  the name of the cookie
   * @return the cookie, if it existed, or null
   */
  @Nullable Cookie removeCookie(String name, boolean invalidate);

  
Returns:
the number of cookies. The context must have first been routed to a CookieHandler for this to work./**
   * @return the number of cookies. The context must have first been routed to a {@link io.vertx.ext.web.handler.CookieHandler}
   * for this to work.
   */
  int cookieCount();

  
Returns:
a set of all the cookies. The context must have first been routed to a CookieHandler for this to be populated./**
   * @return a set of all the cookies. The context must have first been routed to a {@link io.vertx.ext.web.handler.CookieHandler}
   * for this to be populated.
   */
  Set<Cookie> cookies();

  
Returns:
 the entire HTTP request body as a string, assuming UTF-8 encoding. The context must have first been routed to a BodyHandler for this to be populated./**
   * @return  the entire HTTP request body as a string, assuming UTF-8 encoding. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   */
  @Nullable String getBodyAsString();

  
Get the entire HTTP request body as a string, assuming the specified encoding. The context must have first been routed to a BodyHandler for this to be populated. 
Params:
encoding –  the encoding, e.g. "UTF-16"
Returns:
the body/**
   * Get the entire HTTP request body as a string, assuming the specified encoding. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   *
   * @param encoding  the encoding, e.g. "UTF-16"
   * @return the body
   */
  @Nullable String getBodyAsString(String encoding);

  
Returns:
Get the entire HTTP request body as a JsonObject. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * @return Get the entire HTTP request body as a {@link JsonObject}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  @Nullable JsonObject getBodyAsJson();

  
Returns:
Get the entire HTTP request body as a JsonArray. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * @return Get the entire HTTP request body as a {@link JsonArray}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  @Nullable JsonArray getBodyAsJsonArray();

  
Returns:
Get the entire HTTP request body as a Buffer. The context must have first been routed to a BodyHandler for this to be populated./**
   * @return Get the entire HTTP request body as a {@link Buffer}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   */
  @Nullable Buffer getBody();

  
Returns:
a set of fileuploads (if any) for the request. The context must have first been routed to a BodyHandler for this to work./**
   * @return a set of fileuploads (if any) for the request. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to work.
   */
  Set<FileUpload> fileUploads();

  
Get the session. The context must have first been routed to a SessionHandler for this to be populated. Sessions live for a browser session, and are maintained by session cookies. 
Returns:
 the session./**
   * Get the session. The context must have first been routed to a {@link io.vertx.ext.web.handler.SessionHandler}
   * for this to be populated.
   * Sessions live for a browser session, and are maintained by session cookies.
   * @return  the session.
   */
  @Nullable Session session();

  
Get the authenticated user (if any). This will usually be injected by an auth handler if authentication if successful.
Returns:
 the user, or null if the current user is not authenticated./**
   * Get the authenticated user (if any). This will usually be injected by an auth handler if authentication if successful.
   * @return  the user, or null if the current user is not authenticated.
   */
  @Nullable User user();

  
If the context is being routed to failure handlers after a failure has been triggered by calling fail(Throwable) then this will return that throwable. It can be used by failure handlers to render a response, e.g. create a failure response page. 
Returns:
 the throwable used when signalling failure/**
   * If the context is being routed to failure handlers after a failure has been triggered by calling
   * {@link #fail(Throwable)} then this will return that throwable. It can be used by failure handlers to render a response,
   * e.g. create a failure response page.
   *
   * @return  the throwable used when signalling failure
   */
  @CacheReturn
  @Nullable
  Throwable failure();

  
If the context is being routed to failure handlers after a failure has been triggered by calling fail(int) then this will return that status code. It can be used by failure handlers to render a response, e.g. create a failure response page. When the status code has not been set yet (it is undefined) its value will be -1. 
Returns:
 the status code used when signalling failure/**
   * If the context is being routed to failure handlers after a failure has been triggered by calling
   * {@link #fail(int)}  then this will return that status code.  It can be used by failure handlers to render a response,
   * e.g. create a failure response page.
   *
   * When the status code has not been set yet (it is undefined) its value will be -1.
   *
   * @return  the status code used when signalling failure
   */
  @CacheReturn
  int statusCode();

  
If the route specifies produces matches, e.g. produces `text/html` and `text/plain`, and the `accept` header
matches one or more of these then this returns the most acceptable match.
Returns:
 the most acceptable content type./**
   * If the route specifies produces matches, e.g. produces `text/html` and `text/plain`, and the `accept` header
   * matches one or more of these then this returns the most acceptable match.
   *
   * @return  the most acceptable content type.
   */
  @Nullable String getAcceptableContentType();

  
The headers:

Accept
Accept-Charset
Accept-Encoding
Accept-Language
Content-Type
 Parsed into ParsedHeaderValue 
Returns:
A container with the parsed headers./**
   * The headers:
   * <ol>
   * <li>Accept</li>
   * <li>Accept-Charset</li>
   * <li>Accept-Encoding</li>
   * <li>Accept-Language</li>
   * <li>Content-Type</li>
   * </ol>
   * Parsed into {@link ParsedHeaderValue}
   * @return A container with the parsed headers.
   */
  @CacheReturn
  ParsedHeaderValues parsedHeaders();

  
Add a handler that will be called just before headers are written to the response. This gives you a hook where
you can write any extra headers before the response has been written when it will be too late.
Params:
handler –  the handler
Returns:
 the id of the handler. This can be used if you later want to remove the handler./**
   * Add a handler that will be called just before headers are written to the response. This gives you a hook where
   * you can write any extra headers before the response has been written when it will be too late.
   *
   * @param handler  the handler
   * @return  the id of the handler. This can be used if you later want to remove the handler.
   */
  int addHeadersEndHandler(Handler<Void> handler);

  
Remove a headers end handler
Params:
handlerID –  the id as returned from addHeadersEndHandler(Handler<Void>).
Returns:
true if the handler existed and was removed, false otherwise/**
   * Remove a headers end handler
   *
   * @param handlerID  the id as returned from {@link io.vertx.ext.web.RoutingContext#addHeadersEndHandler(Handler)}.
   * @return true if the handler existed and was removed, false otherwise
   */
  boolean removeHeadersEndHandler(int handlerID);

  
Provides a handler that will be called after the last part of the body is written to the wire.
The handler is called asynchronously of when the response has been received by the client.
This provides a hook allowing you to do more operations once the request has been sent over the wire.
Do not use this for resource cleanup as this handler might never get called (e.g. if the connection is reset).
Params:
handler –  the handler
Returns:
 the id of the handler. This can be used if you later want to remove the handler./**
   * Provides a handler that will be called after the last part of the body is written to the wire.
   * The handler is called asynchronously of when the response has been received by the client.
   * This provides a hook allowing you to do more operations once the request has been sent over the wire.
   * Do not use this for resource cleanup as this handler might never get called (e.g. if the connection is reset).
   *
   * @param handler  the handler
   * @return  the id of the handler. This can be used if you later want to remove the handler.
   */
  int addBodyEndHandler(Handler<Void> handler);

  
Remove a body end handler
Params:
handlerID –  the id as returned from addBodyEndHandler(Handler<Void>).
Returns:
true if the handler existed and was removed, false otherwise/**
   * Remove a body end handler
   *
   * @param handlerID  the id as returned from {@link io.vertx.ext.web.RoutingContext#addBodyEndHandler(Handler)}.
   * @return true if the handler existed and was removed, false otherwise
   */
  boolean removeBodyEndHandler(int handlerID);

  
Returns:
true if the context is being routed to failure handlers./**
   * @return true if the context is being routed to failure handlers.
   */
  boolean failed();

  
Set the body. Used by the BodyHandler. You will not normally call this method. 
Params:
body –  the body/**
   * Set the body. Used by the {@link io.vertx.ext.web.handler.BodyHandler}. You will not normally call this method.
   *
   * @param body  the body
   */
  void setBody(Buffer body);

  
Set the session. Used by the SessionHandler. You will not normally call this method. 
Params:
session –  the session/**
   * Set the session. Used by the {@link io.vertx.ext.web.handler.SessionHandler}. You will not normally call this method.
   *
   * @param session  the session
   */
  void setSession(Session session);

  
Set the user. Usually used by auth handlers to inject a User. You will not normally call this method.
Params:
user –  the user/**
   * Set the user. Usually used by auth handlers to inject a User. You will not normally call this method.
   *
   * @param user  the user
   */
  void setUser(User user);

  
Clear the current user object in the context. This usually is used for implementing a log out feature, since the
current user is unbounded from the routing context.
/**
   * Clear the current user object in the context. This usually is used for implementing a log out feature, since the
   * current user is unbounded from the routing context.
   */
  void clearUser();

  
Set the acceptable content type. Used by
Params:
contentType –  the content type/**
   * Set the acceptable content type. Used by
   * @param contentType  the content type
   */
  void setAcceptableContentType(@Nullable String contentType);

  
Restarts the current router with a new path and reusing the original method. All path parameters are then parsed
and available on the params list.
Params:
path – the new http path./**
   * Restarts the current router with a new path and reusing the original method. All path parameters are then parsed
   * and available on the params list.
   *
   * @param path the new http path.
   */
  default void reroute(String path) {
    reroute(request().method(), path);
  }

  
Restarts the current router with a new method and path. All path parameters are then parsed and available on the
params list.
Params:
method – the new http request
path – the new http path./**
   * Restarts the current router with a new method and path. All path parameters are then parsed and available on the
   * params list.
   *
   * @param method the new http request
   * @param path the new http path.
   */
  void reroute(HttpMethod method, String path);

  
Returns the locales for the current request. The locales are determined from the `accept-languages` header and
sorted on quality.
When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
match will be en-US because it was declared as first entry by the client.
Deprecated:
Use acceptableLanguages() or parsedHeaders().ParsedHeaderValues.acceptLanguage()
Returns:
the best matched locale for the request/**
   * Returns the locales for the current request. The locales are determined from the `accept-languages` header and
   * sorted on quality.
   *
   * When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
   * index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
   * match will be en-US because it was declared as first entry by the client.
   *
   * @deprecated Use {@link #acceptableLanguages()} or {@link #parsedHeaders()}.{@link ParsedHeaderValues#acceptLanguage()}
   * @return the best matched locale for the request
   */
  @Deprecated
  @CacheReturn
  List<Locale> acceptableLocales();

  
Returns the languages for the current request. The languages are determined from the Accept-Language
header and sorted on quality.
When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
match will be en-US because it was declared as first entry by the client.
Returns:
The best matched language for the request/**
   * Returns the languages for the current request. The languages are determined from the <code>Accept-Language</code>
   * header and sorted on quality.
   *
   * When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
   * index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
   * match will be en-US because it was declared as first entry by the client.
   *
   * @return The best matched language for the request
   */
  @CacheReturn
  default List<LanguageHeader> acceptableLanguages(){
    return parsedHeaders().acceptLanguage();
  }

  
Helper to return the user preferred locale. It is the same action as returning the first element of the acceptable
locales.
Deprecated:
Use preferredLanguage() instead
Returns:
the users preferred locale./**
   * Helper to return the user preferred locale. It is the same action as returning the first element of the acceptable
   * locales.
   *
   * @deprecated Use {@link #preferredLanguage()} instead
   * @return the users preferred locale.
   */
  @CacheReturn
  @Deprecated
  default Locale preferredLocale() {
    return preferredLanguage();
  }

  
Helper to return the user preferred language.
It is the same action as returning the first element of the acceptable languages.
Returns:
the users preferred locale./**
   * Helper to return the user preferred language.
   * It is the same action as returning the first element of the acceptable languages.
   *
   * @return the users preferred locale.
   */
  @CacheReturn
  default LanguageHeader preferredLanguage() {
    List<? extends LanguageHeader> acceptableLanguages = acceptableLanguages();
    return acceptableLanguages.size() > 0 ? acceptableLanguages.get(0) : null;
  }

  
Returns a map of named parameters as defined in path declaration with their actual values
Returns:
the map of named parameters/**
   * Returns a map of named parameters as defined in path declaration with their actual values
   *
   * @return the map of named parameters
   */
  Map<String, String> pathParams();

  
Gets the value of a single path parameter
Params:
name – the name of parameter as defined in path declaration
Returns:
the actual value of the parameter or null if it doesn't exist/**
   * Gets the value of a single path parameter
   *
   * @param name the name of parameter as defined in path declaration
   * @return the actual value of the parameter or null if it doesn't exist
   */
  @Nullable
  String pathParam(String name);

  
Returns a map of all query parameters inside the query string

The query parameters are lazily decoded: the decoding happens on the first time this method is called. If the query string is invalid
it fails the context
Returns:
the multimap of query parameters/**
   * Returns a map of all query parameters inside the <a href="https://en.wikipedia.org/wiki/Query_string">query string</a><br/>
   * The query parameters are lazily decoded: the decoding happens on the first time this method is called. If the query string is invalid
   * it fails the context
   *
   * @return the multimap of query parameters
   */
  MultiMap queryParams();

  
Gets the value of a single query parameter. For more info queryParams() 
Params:
name – The name of query parameter
Returns:
The list of all parameters matching the parameter name. It returns an empty list if no query parameter with name was found/**
   * Gets the value of a single query parameter. For more info {@link RoutingContext#queryParams()}
   *
   * @param name The name of query parameter
   * @return The list of all parameters matching the parameter name. It returns an empty list if no query parameter with {@code name} was found
   */
  List<String> queryParam(String name);
}