Credit card validator 66

.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/4"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

.gitignore

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+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*

.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>CreditCardValidatorProject</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

.settings/org.eclipse.jdt.core.prefs

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+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8

Base_of_credit_card_vendors.txt

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+Visa 13/16 4 
+MasterCard 16 2221-2720/51-55 

README.md

@@ -1 +1,27 @@
 # recruitment-tl-task-public
+
+## Description
+
+**Please note: Your task is not to write code, but to perform a code review.**
+
+Let's assume you became a leader of the young, immature team, which produces solutions of questionable quality. Below you'll find one of the projects the team is responsible for. Take a look into the repository, do the code review. Point out all the issues with the code quality and how it conforms to clean code (and any other you can think of) principles. Make sure that you look at the code from all possible angles and describe all the possible improvements. Detail all the changes that would have to be done (once again, from all the perspectives you can think of), for this code to become a production ready service (instead of command line application). You could consider resiliency to high loads, things like ddos attacks, auditing etc.
+
+### Task to be reviewed
+#### Task description
+Implement a REST service which validates a credit card number from a common credit card vendor (Visa, MasterCard). Validator should be implemented  in a way that allows extending it easily when adding new card vendors.
+
+#### Task acceptance criteria
+- Request contains only two parameters: card vendor and card number
+- First version should support MasterCard and Visa
+
+## Instructions for candidates
+- once link to recruitment task branch is received, import repository to your Github account
+- create a pull request in your repository
+- add pull request comments in places you find appropriate
+- also respond to production readiness aspects (resiliency, security, etc.) in a summarizing comment
+- make repository public, so that recruiters will be able to review task solution
+
+## Review acceptance criteria
+- code review has a form of GitHub pull request comments 
+- comments are in English
+- code review was finished within a week (168 hours), counting from the moment, when link to recruitment task branch was received

src/validator/CreditCardChecking.java

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+package validator;
+
+public interface CreditCardChecking {
+	public boolean checkValidity(CreditCardVendor ccv, String number);
+}

src/validator/CreditCardValidator.java

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+package validator;
+
+import java.util.ArrayList;
+
+public class CreditCardValidator implements CreditCardChecking {
+
+	@Override
+	public boolean checkValidity(CreditCardVendor ccv, String number) {
+		ArrayList<Integer> chars = ccv.getNumberOfChars();
+		ArrayList<String> masks = ccv.getIIN();
+
+		boolean result1 = checkLengthCorrectness(number, chars);
+		boolean result2 = checkIINMaskCorrectness (number, masks);
+		boolean result3 = checkLuhnalgorithmCorrectness(number);
+
+		return result1 && result2 && result3;
+	}
+
+	private boolean checkLengthCorrectness(String number, ArrayList<Integer> chars){
+		boolean result = false;
+		for (int i = 0; i<chars.size();i++){
+			if (chars.get(i) == number.length())
+				result = true;
+		}
+		return result;
+	}
+
+	private boolean checkIINMaskCorrectness (String number, ArrayList<String> masks){
+		boolean result = false;
+		for (int i = 0; i<masks.size();i++){
+			if (number.startsWith(masks.get(i)))
+				result = true;
+		}
+		return result;
+	}
+
+	private boolean checkLuhnalgorithmCorrectness(String number){
+		boolean result = false;
+
+		String[] characters = number.split("");
+		int[] intCharsReverse = new int[characters.length];
+		int sum = 0;
+
+		for(int i = 0;i<characters.length;i++){
+			intCharsReverse[characters.length-1-i] = Integer.parseInt(characters[i]);
+		}
+
+		for(int i = 0;i<intCharsReverse.length;i++){
+			intCharsReverse[i] = (i%2==1) ? 2*intCharsReverse[i] : intCharsReverse[i];
+		}
+
+		for(int i = 0;i<intCharsReverse.length;i++){
+			sum += (intCharsReverse[i]<10) ? intCharsReverse[i] : (intCharsReverse[i]%10 + intCharsReverse[i]/10);
+		}
+
+		if(sum%10==0)
+			result = true;
+
+		return result;
+	}
+
+}

src/validator/CreditCardValidatorProject.java

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+package validator;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+public class CreditCardValidatorProject {
+
+	private static CreditCardVendorsReader reader = new CreditCardVendorsReader();
+	private static ArrayList<CreditCardVendor> vendors = reader.returnVendorArray();
+	private static CreditCardValidator validator = new CreditCardValidator();
+	private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+	public static void main(String[] args) {
+        System.out.println("CREDIT CARD VALIDATOR\n");
+
+        int vendorsLength = vendors.size();
+        int selected = 0;
+
+        while (true){
+        	printMenu();
+        	try{
+                selected = Integer.parseInt(br.readLine());
+                if(selected < vendorsLength){
+    	        	System.out.println("Type your credit card number:");
+    	        	String cardNumber;
+    				try {
+    					cardNumber = br.readLine();
+    					boolean result = validator.checkValidity(vendors.get(selected), cardNumber);
+    					printResultOfValidation(result);
+    				} catch (IOException e) {
+    					System.out.println("Something went wrong!\n Please retry the process");
+    				}
+
+            	}else{
+            		break;
+            	}
+            }catch(NumberFormatException | IOException e){
+                System.err.println("Invalid Format!");
+            }
+
+        }
+
+    }
+
+	static private void printMenu(){
+		System.out.println("Select your card vendor from list below("+vendors.size()+" exits):");
+    	for (int i = 0;i<vendors.size();++i)
+    		System.out.println(i+" "+vendors.get(i).toString());
+	}
+
+	static private void printResultOfValidation(boolean result){
+		if(result){
+    		System.out.println("\n\nCard number is valid.\n");
+    	}else{
+    		System.out.println("\n\nCard number is invalid!\n");
+    	}
+	}
+}

src/validator/CreditCardVendor.java

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+package validator;
+
+import java.util.ArrayList;
+
+public class CreditCardVendor {
+	private String name;
+	private ArrayList<Integer> numberOfChars;
+	private ArrayList<String> IIN;
+
+	public String getName(){
+		return name;
+	}
+
+	public ArrayList<Integer> getNumberOfChars(){
+		return numberOfChars;
+	}
+
+	public ArrayList<String> getIIN(){
+		return IIN;
+	}
+
+	public CreditCardVendor(String vendorName, ArrayList<Integer> charsNumbers, ArrayList<String> masks){
+		name = vendorName;
+		numberOfChars = charsNumbers;
+		IIN = masks;
+	}
+
+	@Override
+	public String toString(){
+		return name;
+	}
+}

src/validator/CreditCardVendorReading.java

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+package validator;
+
+import java.util.ArrayList;
+
+public interface CreditCardVendorReading {
+	public ArrayList<CreditCardVendor> returnVendorArray();
+}

src/validator/CreditCardVendorsReader.java

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+package validator;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class CreditCardVendorsReader implements CreditCardVendorReading {
+	@Override
+	public ArrayList<CreditCardVendor> returnVendorArray() {
+		ArrayList<CreditCardVendor> list = new ArrayList<CreditCardVendor>();
+
+		try(BufferedReader br = new BufferedReader(new FileReader("Base_of_credit_card_vendors.txt"))) {
+		    for(String line; (line = br.readLine()) != null; ) {
+		        String[] values = line.split(" ");
+
+		        String vendorName = values[0];
+		        ArrayList<Integer> vendorNumbersOfChars = new ArrayList<Integer>();
+		        ArrayList<String> vendorMasks = new ArrayList<String>();
+
+		        parseLengths(values[1], vendorNumbersOfChars);
+		        parseMasks(values[2], vendorMasks);
+
+		        list.add(new CreditCardVendor(vendorName,vendorNumbersOfChars,vendorMasks));
+
+		    }
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+		return list;
+	}
+
+	private void parseLengths(String value, ArrayList<Integer> vendorNumbersOfChars){
+		String[] values = value.split("/");
+		for(int i=0; i<values.length; i++){
+        	vendorNumbersOfChars.add(Integer.parseInt(values[i]));
+        }
+	}
+
+	private void parseMasks(String value,  ArrayList<String> vendorMasks){
+	     String[] masks = value.split("/");
+	     for(int i=0;i<masks.length; i++){
+	     	if (masks[i].split("-").length == 1){
+	     		vendorMasks.add(masks[i]);
+	     	}else{
+	     		long min= Long.parseLong((masks[i].split("-"))[0]);
+	     		long max= Long.parseLong((masks[i].split("-"))[1]);
+	     		for (long j = min; j<=max;j++)
+	     			vendorMasks.add(""+j);
+	     	}
+	     }
+	}
+
+}

src/validator/Tests.java

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+package validator;
+
+import static org.junit.Assert.*;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+import org.junit.Test;
+
+public class Tests {
+	private static CreditCardVendorsReader reader = new CreditCardVendorsReader();
+	private static ArrayList<CreditCardVendor> vendors = reader.returnVendorArray();
+	private static CreditCardValidator validator = new CreditCardValidator();
+	private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	private static CreditCardVendor vendorMasterCard = vendors.get(1);
+
+
+	@Test
+	public void testLengthOfNumberWhenCorrect() {
+		String number = "5584239583699571";
+		assertEquals(true, validator.checkValidity(vendorMasterCard, number));
+	}
+
+	@Test
+	public void testLengthOfNumberWhenIncorrect() {
+		String number = "55842395";
+		assertEquals(false, validator.checkValidity(vendorMasterCard, number));
+	}
+
+	@Test
+	public void testIINWhenCorrect() {
+		String number = "5584239583699571";
+		assertEquals(true, validator.checkValidity(vendorMasterCard, number));
+	}
+
+	@Test
+	public void testIINWhenIncorrect() {
+		String number = "7784239583699571";
+		assertEquals(false, validator.checkValidity(vendorMasterCard, number));
+	}
+
+	@Test
+	public void testLuhnAlghoritmWhenCorrect() {
+		String number = "5584239583699571";
+		assertEquals(true, validator.checkValidity(vendorMasterCard, number));
+	}
+
+	@Test
+	public void testLuhnAlghoritmWhenIncorrect() {
+		String number = "5584239583611111";
+		assertEquals(false, validator.checkValidity(vendorMasterCard, number));
+	}
+
+}