Add API WEB service with endpoint for IBAN validation

Author: skarware

IBANList.txt.out

@@ -14,6 +14,7 @@
  <java.version>11</java.version>
  <maven.compiler.source>11</maven.compiler.source>
  <maven.compiler.target>11</maven.compiler.target>
+ <jetty.version>9.4.30.v20200611</jetty.version>
  </properties>
 
  <dependencies>
@@ -22,6 +23,21 @@
  <artifactId>commons-validator</artifactId>
  <version>1.6</version>
  </dependency>
+ <dependency>
+ <groupId>javax.servlet</groupId>
+ <artifactId>javax.servlet-api</artifactId>
+ <version>4.0.1</version>
+ </dependency>
+ <dependency>
+ <groupId>org.eclipse.jetty</groupId>
+ <artifactId>jetty-server</artifactId>
+ <version>${jetty.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>org.eclipse.jetty</groupId>
+ <artifactId>jetty-servlet</artifactId>
+ <version>${jetty.version}</version>
+ </dependency>
  </dependencies>
 
  <build>

pom.xml

@@ -0,0 +1,39 @@
+package edu.task.technical.ibanvalidator.service;
+
+import edu.task.technical.ibanvalidator.servlet.IBANValidationServlet;
+import org.eclipse.jetty.server.Connector;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.servlet.ServletHandler;
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
+
+public class HttpService {
+
+ private Server httpJettyServer;
+
+ void start(int WebPort) throws Exception {
+
+ int maxThreads = 100;
+ int minThreads = 10;
+ int idleTimeout = 120;
+
+ QueuedThreadPool threadPool = new QueuedThreadPool(maxThreads, minThreads, idleTimeout);
+
+ httpJettyServer = new Server(threadPool);
+ ServerConnector connector = new ServerConnector(httpJettyServer);
+ connector.setPort(WebPort);
+ httpJettyServer.setConnectors(new Connector[]{connector});
+
+ ServletHandler servletHandler = new ServletHandler();
+ httpJettyServer.setHandler(servletHandler);
+
+ servletHandler.addServletWithMapping(IBANValidationServlet.class, "/api/ibanvalidator");
+
+ httpJettyServer.start();
+ }
+
+ void stop() throws Exception {
+ httpJettyServer.stop();
+ }
+
+}

src/main/java/edu/task/technical/ibanvalidator/service/HttpService.java

@@ -17,6 +17,8 @@ public class IBANValidationService {
  // Get dependencies
  private final CLIService cliService = new CLIService();
  private final FileService fileService = new FileService();
+ private final HttpService httpService = new HttpService();
+
 
  // Prints passed IBAN code and its validation to STDOUT
  private void printCodeAndValidation(String ibanCode) {
@@ -28,10 +30,9 @@ private void printCodeAndValidation(String ibanCode) {
  public void start(String[] args) {
  // Check if arguments from command line passed has an API argument
  if (args.length > 0) {
+ // If so then run as WEB service and expose API endpoint
  if (args[0].toLowerCase().equals("api")) {
- // if so then run as WEB service and expose API endpoints
- // TODO: implement servlet to provide REST API service
- System.err.println("Sorry, API functionality has not been yet implemented");
+ this.initiateAPIMode(args);
  } else {
  System.err.println("Unknown option, try 'api'");
  }
@@ -41,6 +42,30 @@ public void start(String[] args) {
  }
  }
 
+ private void initiateAPIMode(String[] args) {
+ // Default port to 8080
+ int port = 8080;
+
+ // If port passed as a second argument then parse it as integer and pass as the argument to a httpServer or exit program on error
+ if (args.length > 1) {
+ if (args[1] != null) {
+ try {
+ port = Integer.parseInt(args[1]);
+ } catch (NumberFormatException exception) {
+ System.err.println("Could not parse port number, make sure it is a number");
+ exitProgram();
+ }
+ }
+ }
+ // Try to start Http Server, if any problem exit the program
+ try {
+ this.httpService.start(port);
+ } catch (Exception e) {
+ System.err.println("Could not start Http server");
+ exitProgram();
+ }
+ }
+
  // Overloaded procedure to start IBANValidationService, shortcut to run as CLI version
  public void start() {
  this.initiateCLIMainMenu();
@@ -50,6 +75,13 @@ public void start() {
  private void exitProgram() {
  System.out.println("\n\tProgram exiting,\n\t\t\t see you...");
 
+ // Wait for http server operations to finish before exiting program
+ try {
+ this.httpService.stop();
+ } catch (Exception e) {
+ System.err.println("Failed to gracefully stop Http Server");
+ }
+
  // exit the application
  System.exit(0);
  }
@@ -70,8 +102,8 @@ private void initiateCLIMainMenu() {
  this.readIBANsFileValidateSaveResult(this.ibanCodeList);
 
  } else if (userOption == 99 || userOption == 67) { // if key == 'c' or C
- // TODO: invoke servlet API
- System.out.println("Sorry, API functionality has not been yet implemented");
+ // Invoke servlet API
+ this.initiateAPIMode(new String[]{});
 
  } else if (userOption == 101 || userOption == 69) { // if key == 'e' or E
  // Exit the program

src/main/java/edu/task/technical/ibanvalidator/service/IBANValidationService.java

@@ -0,0 +1,26 @@
+package edu.task.technical.ibanvalidator.servlet;
+
+import org.apache.commons.validator.routines.IBANValidator;
+
+import javax.servlet.ServletException;
+
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+public class IBANValidationServlet extends HttpServlet {
+
+ // Get a singleton instance of the IBAN validator using the default formats
+ private final IBANValidator ibanValidator = IBANValidator.getInstance();
+
+ public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
+
+ String iban = req.getParameter("iban");
+
+ res.setContentType("application/json");
+ res.setStatus(HttpServletResponse.SC_OK);
+ res.getWriter().println("{\"" + iban + "\": \"" + ibanValidator.isValid(iban) + "\"}");
+ }
+
+}