我有一段丑陋的巨大代码。它可以做很多事情，主要是查询数据库。每个查询都取决于上一个查询的结果或传入请求体的参数。查询是使用Future异步完成的。代码有效，但不可读。我如何重组它以使其简洁？我曾想过使用for而不是map和flatMap，但由于对以前查询的依赖性，我无法弄清楚如何在新查询中使用以前Future的结果以及如何处理错误路径。
我正在使用play 2.6和scala 2.12.2
def oldSignupUser:Action[AnyContent] = silhouette.UserAwareAction.async {
implicit request => {
val body: AnyContent = request.body
val jsonBody: Option[JsValue] = body.asJson
jsonBody match {
case Some(json) => {
val userProfile: Option[UserProfile] = json.asOpt[UserProfile] userProfile match {
case Some(profile) => {
val loginInfo = LoginInfo(CredentialsProvider.ID, profile.externalProfileDetails.email)
val userKeys = UserKeys(utilities.bucketIDFromEmail(profile.externalProfileDetails.email),profile.externalProfileDetails.email,loginInfo,profile.externalProfileDetails.firstName,profile.externalProfileDetails.lastName)
val findUserFuture: Future[Option[User]] = userRepo.findOne(userKeys) // userFuture will eventually contain the result of database query i.e Some(user) or None
findUserFuture.flatMap { (userOption: Option[User]) =>
userOption match {
case Some(user) => {
if(user.profile.internalProfileDetails.get.confirmed) {
Future {
Ok(Json.toJson(JsonResultError(messagesApi("error.duplicateUser")(langs.availables(0)))))
}
} else {
val userKeys = UserKeys(utilities.bucketIDFromEmail(user.profile.externalProfileDetails.email),user.profile.externalProfileDetails.email,loginInfo,user.profile.externalProfileDetails.firstName,user.profile.externalProfileDetails.lastName)
val userToken:UserToken = utilities.createUserToken(user.id,userKeys,UserTokenType.RegistrationConfirmation)
val userTokenSaveFuture:Future[Option[UserToken]] = userTokenRepo.save(userToken)
logger.trace(s"user token save future ${userTokenSaveFuture}")
userTokenSaveFuture.map( (userTokenOption:Option[UserToken])=>{
userTokenOption match {
case Some(userToken) => {
val signupEmailOption:Option[SignupEmail] = createEmailMessageForUserToken(userToken)
signupEmailOption match {
case Some(signupEmail:SignupEmail) =>{
val _:String = mailerService.sendEmail(signupEmail.subject, signupEmail.from,List(user.profile.externalProfileDetails.email),None,Some(signupEmail.html))
Ok(Json.toJson(JsonResultSuccess(messagesApi("success.userSignupConfirmationEmailSent")(langs.availables(0)))))
}
case None =>{
InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))
}
}
}
case None => {
Ok(Json.toJson(JsonResultError("user not added"))) //Todom - this is misleading as user is added but token isn't
}
}
})
}
}
case None => {
val passwordInfo:PasswordInfo = userRepo.hashPassword(profile.externalProfileDetails.password.get)
val bucketId = utilities.bucketIDFromEmail(profile.externalProfileDetails.email)
val newUser:User = User(
utilities.getUniqueID(),//UUID.randomUUID(),
UserProfile(Some(InternalUserProfile(loginInfo,bucketId,false,Some(passwordInfo))),
profile.externalProfileDetails))
val saveUserFuture:Future[Option[User]] = userRepo.save(newUser)
saveUserFuture.flatMap { (userOption:Option[User]) =>{ userOption match {
case Some(user) => {
val initialPortfolio = user.profile.externalProfileDetails.portfolio
val profileAndPortfolio = profile.externalProfileDetails.copy(portfolio = initialPortfolio)
logger.trace(s"saving external profile and portfolio ${profileAndPortfolio}")
val savedProfileAndPortfolioOptionFuture = userProfileAndPortfolioRepo.save(profileAndPortfolio)
savedProfileAndPortfolioOptionFuture.flatMap(profileAndPortfolioOption =>{
profileAndPortfolioOption match {
case Some(profileAndPortfolio) => {
val userKeys = UserKeys(utilities.bucketIDFromEmail(user.profile.externalProfileDetails.email),user.profile.externalProfileDetails.email,loginInfo,user.profile.externalProfileDetails.firstName,user.profile.externalProfileDetails.lastName)
val userToken:UserToken = utilities.createUserToken(user.id,userKeys,UserTokenType.RegistrationConfirmation)
val userTokenSaveFuture:Future[Option[UserToken]] = userTokenRepo.save(userToken)
userTokenSaveFuture.flatMap( (userTokenOption:Option[UserToken])=>{
userTokenOption match {
case Some(userToken) => {
val signupEmailOption = createEmailMessageForUserToken(userToken)
signupEmailOption match {
case Some(signupEmail) =>{
val _:String = mailerService.sendEmail(signupEmail.subject,signupEmail.from,List(user.profile.externalProfileDetails.email),None,Some(signupEmail.html))
Future{Ok(Json.toJson(JsonResultSuccess((messagesApi("success.userSignupConfirmationEmailSent"))(langs.availables(0)))))}
}
case None =>{
Future{InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))}
}
}
}
case None => {
Future{Ok(Json.toJson(JsonResultError("user not added"))) }
}
}
})
}
case None =>{
Future{InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))}
}
}
})
}
case None => {
Future{Ok(Json.toJson(JsonResultError("unable to add user")))}
}
}
}
}
.recover { case x => {
x match {
case _:EmailException =>InternalServerError(Json.toJson(JsonResultError("The server encountered internal error and couldn't sent email to the email id.")))
case _ => InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))
}
}
}
}
}
}
.recover { case x => {
logger.trace("Future failed in signupUser. In recover. Returning Internal Server Error"+x)
x match {
case _:EmailException =>InternalServerError(Json.toJson(JsonResultError("The server encountered internal error and couldn't sent email to the email id.")))
case _ => InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))
}
}
}
}
case None => Future {
logger.trace("invalid profile structure")
Ok(Json.toJson(JsonResultError(messagesApi("error.incorrectBodyStructure")(langs.availables(0))))) }
}
}
case None => Future {
Ok(Json.toJson(JsonResultError(messagesApi("error.incorrectBodyType")(langs.availables(0))))) }
}
}
}
更新-在我解决问题之前，问题已经结束。非常感谢mfirry和tim的回答。这是我能想到的版本，我相信它是模块化的。
def getUserProfileFromBody(json:JsValue): Option[UserProfile] ={
val userProfile = json.asOpt[UserProfile] //check if json conforms with UserProfile structure
userProfile
}
def getJsonBody(body:AnyContent) = {
val jsonBody: Option[JsValue] = body.asJson
jsonBody
}
def generateUserKeysFromUserProfile(profile:UserProfile):UserKeys = {
val loginInfo = LoginInfo(/*provider id eg "credentials"*/CredentialsProvider.ID, /*provider Key eg email*/profile.externalProfileDetails.email)
val userKeys = UserKeys(utilities.bucketIDFromEmail(profile.externalProfileDetails.email),profile.externalProfileDetails.email,loginInfo,profile.externalProfileDetails.firstName,profile.externalProfileDetails.lastName)
logger.trace(s"generated userkey ${userKeys}")
userKeys
}
def findIfUserIsNewOrExisting(userKey:UserKeys): Future[Boolean] ={
logger.trace(s"looking for user with keys ${userKey}")
val findUserFuture = userRepo.findOne(userKey) // userFuture will eventually contain the result of database query i.e Some(user) or None
logger.trace(s"user future is ${findUserFuture}")
for(userOption <- findUserFuture) yield {
logger.trace(s"user option ${userOption}")
userOption match {
case Some(user) => {
val userConfirmed = isUserConfirmed(user)
if(userConfirmed) {
throw new DuplicateUserException(user,"duplicateuser", new Throwable("duplicateuser"))
} else throw new UnconfirmedUserException(user,"unconfirmeduser", new Throwable("unconfirmeduser"))
}
case None => {
false
}
}
}
}
def returnError(error:String) = {
println(s"returning error ${error}")
Future {
/*
note the distintion between langs and messages. Lang means languages this application supports
eg English, French
Messages are the messages defined per language. Eg app.title is a message defined inn English. It might not be defined in French
*/
/*logger.trace("langs array"+langs.availables) //languages available
logger.trace("app.title: "+messagesApi.isDefinedAt("app.title")(langs.availables(0)))//pick the first language and see taht app.title is defined in it
logger.trace("error: "+messagesApi.isDefinedAt("error.incorrectBodyType")(langs.availables(0)))//see taht error.incorrectBodyType is defined in the 1st language
*/
Ok(Json.toJson(JsonResultError(error)))
}/*TODOM - Standardise error messages. Use as constants*/
}
def isUserConfirmed(user:User):Boolean = user.profile.internalProfileDetails.get.confirmed
def sendConfirmationTokenForUser(user:User) = {
val userKeys = generateUserKeysFromUserProfile(user.profile)
//for this user, create a token which could be sent in the email for verification
val userToken:UserToken = utilities.createUserToken(user.id,userKeys,UserTokenType.RegistrationConfirmation)
logger.trace(s"saving token ${userToken}")
val userTokenSaveFuture:Future[Option[UserToken]] = userTokenRepo.save(userToken)
logger.trace(s"user token save future ${userTokenSaveFuture}")
for(userTokenOption <- userTokenSaveFuture) yield {
logger.trace(s"user token ${userTokenOption}")
userTokenOption match {
case Some(userToken) => {
val signupEmailOption:Option[SignupEmail] = createEmailMessageForUserToken(userToken)
signupEmailOption match {
case Some(signupEmail:SignupEmail) =>{
val email = mailerService.sendEmail(signupEmail.subject, signupEmail.from,List(user.profile.externalProfileDetails.email),None,Some(signupEmail.html))
println(s"sent email message ${email}")
email
//Ok(Json.toJson(JsonResultSuccess(messagesApi("success.userSignupConfirmationEmailSent")(langs.availables(0)))))
}
case None =>{
logger.trace("unable to create html response for email confirmation")
//InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))
throw EmailMessageCreationException("errorInCreatingHTML", new Throwable("errorInCreatingHTML"))
}
}
}
case None => {
logger.trace("error in adding token")
throw EmailTokenSaveException("emailTokenSaveException", new Throwable("emailTokenSaveException"))
//Ok(Json.toJson(JsonResultError("user not added"))) //Todom - this is misleading as user is added but token isn't
}
}
}
}
def addUserToDatabase(user:User) = {
println(s"saving user ${user}")
val saveUserFuture:Future[Option[User]] = userRepo.save(user)
for(userOption <- saveUserFuture) yield {
userOption match {
case Some(user) => {
logger.trace("user added successfully "+user)
user
}
case None => throw new NewUserAdditionException("newUserAdditionError", new Throwable("newUserAdditionError"))
}
}
}
def addNewUser(profile:UserProfile) = {
logger.trace(s"new user sign up request with profile ${profile}")
////NOTE - //salt is empty for BCryptSha256PasswordHasher. The 'hash' method of BCryptSha256PasswordHasher does not return the salt separately because it is embedded in the hashed password.
//should creation of passwordInfo be moved to UserRepo? Not sure.
//A profile associated with the credentials provider stores a Silhouette PasswordInfo object holding the hashed password
//val passwordInfo:PasswordInfo = userRepo.passwordHasher.hash(profile.externalProfileDetails.password.get)
val passwordInfo: PasswordInfo = userRepo.hashPassword(profile.externalProfileDetails.password.get)
//logger.trace("password info is ",passwordInfo)
val bucketId = utilities.bucketIDFromEmail(profile.externalProfileDetails.email)
val loginInfo = LoginInfo(/*provider id eg "credentials"*/ CredentialsProvider.ID, /*provider Key eg email*/ profile.externalProfileDetails.email)
val newUser: User = User(
utilities.getUniqueID(), //UUID.randomUUID(),
UserProfile(Some(InternalUserProfile(loginInfo, bucketId, false, Some(passwordInfo))),
profile.externalProfileDetails))
logger.trace("adding new user" + newUser)
addUserToDatabase(newUser)
}
def saveProfileAndPortfolio(profileAndPortfolio:ExternalUserProfile) = {
logger.trace(s"saving external profile and portfolio ${profileAndPortfolio}")
val savedProfileAndPortfolioOptionFuture = userProfileAndPortfolioRepo.save(profileAndPortfolio)
for(savedProfileAndPortfolio <- savedProfileAndPortfolioOptionFuture) yield {
savedProfileAndPortfolio match {
case Some(profileAndPortfolio) => profileAndPortfolio
case None => throw ProfileAndPortfolioAdditionException("profileAndPortfolioAdditionException",new Throwable("profileAndPortfolioAdditionException"))
}
}
}
def createUserProfileAndPortfolioInformation(user:User) = {
val profile = user.profile
val initialPortfolio = user.profile.externalProfileDetails.portfolio //Some(TagsOfInterestToAUserAPI(Set(),Set(),Set()))
val profileAndPortfolio = profile.externalProfileDetails.copy(portfolio = initialPortfolio)
saveProfileAndPortfolio(profileAndPortfolio)
}
def signupUser = silhouette.UserAwareAction.async {
implicit request => {
logger.trace(s"received request ${request}")
val jsonBody = getJsonBody(request.body)
/*
TODOM - testcase - check what happens if some other body type is sent.
*/
jsonBody match {
case Some(json) => { //got json in message body.
//TODOM - convert to pretty print only if logger level is trace
val readableString: String = Json.prettyPrint(json)
logger.trace(s"received Json ${readableString}")
val userProfile = getUserProfileFromBody(json)
userProfile match {
case Some(profile) => { //json conforms to UserProfile.
logger.trace(s"received correct profile structure ${profile}")
val userKeys = generateUserKeysFromUserProfile(profile)
val res = for{isNewUser <- findIfUserIsNewOrExisting(userKeys) //this will throw error if user is duplicate
newUserDetails <- addNewUser(profile)
profileAndPortfolioInfo <- createUserProfileAndPortfolioInformation(newUserDetails)
confirmationEmail <- sendConfirmationTokenForUser(newUserDetails)} yield {
Ok(Json.toJson(JsonResultSuccess((messagesApi("success.userSignupConfirmationEmailSent"))(langs.availables(0)))))
}
res.recover {
case exception: DuplicateUserException => Ok(Json.toJson(JsonResultError(messagesApi("error.duplicateUser")(langs.availables(0)))))
case exception: UnconfirmedUserException => {
sendConfirmationTokenForUser(exception.user)
Ok(Json.toJson(JsonResultSuccess((messagesApi("success.userSignupConfirmationEmailSent"))(langs.availables(0)))))
}
case _:EmailException =>InternalServerError(Json.toJson(JsonResultError("The server encountered internal error and couldn't sent email to the email id.")))
case exception:ProfileAndPortfolioAdditionException => Ok(Json.toJson(JsonResultError("user not added")))
case _:EmailMessageCreationException => Ok(Json.toJson(JsonResultError("user not added")))
case _: EmailTokenSaveException=> Ok(Json.toJson(JsonResultError("user not added")))
case x => {
logger.error(s"unknown exception ${x}")
InternalServerError(Json.toJson(JsonResultError("Internal Server Error")))
}
}
res
}
//Json doesn't conform to UserProfile
case None => Future {
logger.trace("invalid profile structure")
Ok(Json.toJson(JsonResultError(messagesApi("error.incorrectBodyStructure")(langs.availables(0))))) } /*TODOM - Standardise error messages. Use as constants*/
}
}
//message body is not json. Error.
//TODOM - langs contains array of lang. picking the 1st one but would need too pick based on locale.
//langs.availables(0) maps to array defined in application.conf eg. - play.i18n.langs = [ "en", "en-US", "fr" ]
case None =>{
logger.trace("incorrect body type")
returnError(messagesApi("error.incorrectBodyType")(langs.availables(0)))
}
}
}
}
最明显的变化是将代码放入函数中。通过将逻辑分解为具有有意义名称的函数，可以使代码读起来更加清晰。如果将它们定义为方法中的本地函数，则它们可以从方法访问上下文，而不必将其作为参数传入。
将所有错误返回放在方法外部的静态val中，而不是每次都创建它们。
考虑使用Option.fold而不是match:
option.fold(error){ result =>
// Further code
}
删除case x =>之后的{}，它们不是必需的。
case x => { x match {中的第一个case是冗余的。
在您能够证明这部分代码的性能对应用程序的行为有实质性影响之前，不要担心性能。
一个问题是，您没有使用Future的Failure情况来指示失败，因此您不能使用map/flatMap来连锁可能失败的操作。
创建自己的Exception子类，并让方法在失败时返回Future.failed(MyException(error))，而不是Future(error)
然后进行
val res =
for {
res1 <- futureAction1
res2 <- futureAction2(res1)
res3 <- futureAction3(res2)
} yield {
res3
}
最后是
res.recover{ case MyException(err) => err }
for将在第一个Failure返回值处停止，而recover将其转换为适当的Success值。