What is Scala: Proxy Design Pattern

This Structural design pattern is also known as the proxy design pattern. This structural pattern for designing is very much useful in the creation of a representative object which can control the access to another object. With the help of Scala Development, the object can either be remote or sometimes be really very expensive. The major objective of the proxy design pattern is to provide a surrogate or the placeholder pattern for the other object in order to access the control.

In the Proxy Design Pattern, the word proxy means representing. The other alternative words for the proxies are handlers, wrapper as well as the surrogates. In Spark Development, the proxy patterns can control and manage access to the objects they desire to protect. These proxies can be chained together forming a big network. The Client and each proxy delegates the information and the messages to the actual server in the **Scala Development**.

Initially, in many applications, the user-specific details like username, phone number were easily logged without the process of scrambling. But now it is compulsory for the Spark Developer to ensure the scrambling of all these user-specific data. In order to bring about this change in the Scala & Spark Development, a proxy class needs to be added between the logging framework designed and the client.

The proxy is the class that functions as the interface to other structures. Once, the Logger Proxy class gets created that gets called before the framework gets called. This will do the process of scrambling the logs in the Spark Development and then the various logging framework methods will be called. One of the important files is build.sbt file that had all project settings. Dependency like slf4j is used in order to add the logging framework to the application. Below is the UML Class and Sequence diagram for the sample Proxy design pattern.

In the above Development, the Proxy class will be implementing the Subject interface thereby acting as an alternative for the Subject objects. Sequence diagram here shows the implementation of the run-time interactions. From the above example, the client object will be working through the Proxy object that does the process of controlling full access to the RealSubject object. In the Scala Development, the Proxy class cleanly maintains the reference to the substituted object such that the requests can be forwarded to it like the realSubject.operation().

name := “ProxyDesignPattern”

version := “0.1”

scalaVersion := “2.12.6”

libraryDependencies ++= Seq(“org.slf4j” % “slf4j-api” % “1.7.5”,

“org.slf4j” % “slf4j-simple” % “1.7.5”)

In the Scala Development, this is where the library dependency gets added along with the Scala version and name by the Scala Developer. The next step will be to create a client class that calls the logging methods.

object Client extends App {

val logger = LoggerProxy.getLogger(this.getClass.getName)

logger.info(“Log Contains IP address: 127.0.0.1”)

logger.debug(“UserName: jainnancy trying to sign in”)

logger.error(“Password: abxyz is wrong “)

Here, in the Scala Development, the different logging methods get called by the Scala Developer leading to its execution.

The LoggerHelper class performs the scrambling of the logs.

class LoggerHelper {

private val regex = “\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b”

private val password = “Password: “

private val userName = “UserName: “

def scramble(message : String) = scrambleUsername(scrambleIp((scramblePassword(message))))

private def scrambleUsername(message : String) = {

if(message.contains(userName)) {

val index = message.indexOf(userName) + userName.length()

val textStartedPassword = message.substring(index)

message.substring(0, index) + “X” + textStartedPassword.substring(textStartedPassword.indexOf(“ “))

}

else {

message

}

}

private def scrambleIp(message : String) = message.replaceAll(regex, “XXX.XXX.XXX.XXX”)

private def scramblePassword(message : String) = {

if(message.contains(password)) {

val index = message.indexOf(password) + password.length()

val textStartedPassword = message.substring(index)

message.substring(0, index) + “X” + textStartedPassword.substring(textStartedPassword.indexOf(“ “))

}

else {

message

}

}

}

One more class must be implemented such that the class will be acting as the proxy between the client and the logging framework. By this, Spark Developer would ensure that the logs get scrambled before the logging process begins. In Scala Development, this LoggerProxy class implements the Logger Interface. This interface is defined in the slf4j framework. These proxy design patterns can solve control access to the object. The proxy design patterns play a significant role in Scala Development Services by designing the flexible and reusable object-oriented type of software.