BAEL-325: Refactored to use multi-module structure.

patterns/front-controller/pom.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>front-controller</artifactId>
+    <packaging>war</packaging>
+
+    <parent>
+        <artifactId>patterns-parent</artifactId>
+        <groupId>com.baeldung.patterns</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>..</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-war-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.eclipse.jetty</groupId>
+                <artifactId>jetty-maven-plugin</artifactId>
+                <configuration>
+                    <webApp>
+                        <contextPath>/front-controller</contextPath>
+                    </webApp>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/FrontControllerServlet.java

@@ -0,0 +1,38 @@
+package com.baeldung.patterns.front.controller;
+
+import com.baeldung.patterns.front.controller.commands.FrontCommand;
+import com.baeldung.patterns.front.controller.commands.UnknownCommand;
+
+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 FrontControllerServlet extends HttpServlet {
+    @Override
+    protected void doGet(
+      HttpServletRequest request,
+      HttpServletResponse response
+    ) throws ServletException, IOException {
+        FrontCommand command = getCommand(request);
+        command.init(getServletContext(), request, response);
+        command.process();
+    }
+
+    private FrontCommand getCommand(HttpServletRequest request) {
+        try {
+            Class type = Class.forName(
+              String.format(
+                "com.baeldung.patterns.front.controller.commands.%sCommand",
+                request.getParameter("command")
+              )
+            );
+            return (FrontCommand) type
+              .asSubclass(FrontCommand.class)
+              .newInstance();
+        } catch (Exception e) {
+            return new UnknownCommand();
+        }
+    }
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/commands/FrontCommand.java

@@ -0,0 +1,32 @@
+package com.baeldung.patterns.front.controller.commands;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+public abstract class FrontCommand {
+    protected ServletContext context;
+    protected HttpServletRequest request;
+    protected HttpServletResponse response;
+
+    public void init(
+      ServletContext servletContext,
+      HttpServletRequest servletRequest,
+      HttpServletResponse servletResponse
+    ) {
+        this.context = servletContext;
+        this.request = servletRequest;
+        this.response = servletResponse;
+    }
+
+    public abstract void process() throws ServletException, IOException;
+
+    protected void forward(String target) throws ServletException, IOException {
+        target = String.format("/WEB-INF/jsp/%s.jsp", target);
+        RequestDispatcher dispatcher = context.getRequestDispatcher(target);
+        dispatcher.forward(request, response);
+    }
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/commands/SearchCommand.java

@@ -0,0 +1,21 @@
+package com.baeldung.patterns.front.controller.commands;
+
+import com.baeldung.patterns.front.controller.data.Book;
+import com.baeldung.patterns.front.controller.data.BookshelfImpl;
+
+import javax.servlet.ServletException;
+import java.io.IOException;
+
+public class SearchCommand extends FrontCommand {
+    @Override
+    public void process() throws ServletException, IOException {
+        Book book = new BookshelfImpl().getInstance()
+          .findByTitle(request.getParameter("title"));
+        if (book != null) {
+            request.setAttribute("book", book);
+            forward("book-found");
+        } else {
+            forward("book-notfound");
+        }
+    }
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/commands/UnknownCommand.java

@@ -0,0 +1,11 @@
+package com.baeldung.patterns.front.controller.commands;
+
+import javax.servlet.ServletException;
+import java.io.IOException;
+
+public class UnknownCommand extends FrontCommand {
+    @Override
+    public void process() throws ServletException, IOException {
+        forward("unknown");
+    }
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/data/Book.java

@@ -0,0 +1,15 @@
+package com.baeldung.patterns.front.controller.data;
+
+public interface Book {
+    String getAuthor();
+
+    void setAuthor(String author);
+
+    String getTitle();
+
+    void setTitle(String title);
+
+    Double getPrice();
+
+    void setPrice(Double price);
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/data/BookImpl.java

@@ -0,0 +1,46 @@
+package com.baeldung.patterns.front.controller.data;
+
+public class BookImpl implements Book {
+    private String author;
+    private String title;
+    private Double price;
+
+    public BookImpl() {
+    }
+
+    public BookImpl(String author, String title, Double price) {
+        this.author = author;
+        this.title = title;
+        this.price = price;
+    }
+
+    @Override
+    public String getAuthor() {
+        return author;
+    }
+
+    @Override
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+
+    @Override
+    public String getTitle() {
+        return title;
+    }
+
+    @Override
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    @Override
+    public Double getPrice() {
+        return price;
+    }
+
+    @Override
+    public void setPrice(Double price) {
+        this.price = price;
+    }
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/data/Bookshelf.java

@@ -0,0 +1,15 @@
+package com.baeldung.patterns.front.controller.data;
+
+public interface Bookshelf {
+
+    default void init() {
+        add(new BookImpl("Wilson, Robert Anton & Shea, Robert", "Illuminati", 9.99));
+        add(new BookImpl("Fowler, Martin", "Patterns of Enterprise Application Architecture", 27.88));
+    }
+
+    Bookshelf getInstance();
+
+    <E extends Book> boolean add(E book);
+
+    Book findByTitle(String title);
+}

patterns/front-controller/src/main/java/com/baeldung/patterns/front/controller/data/BookshelfImpl.java

@@ -0,0 +1,24 @@
+package com.baeldung.patterns.front.controller.data;
+
+import java.util.ArrayList;
+
+public class BookshelfImpl extends ArrayList<Book> implements Bookshelf {
+    private static Bookshelf INSTANCE;
+
+    @Override
+    public Bookshelf getInstance() {
+        if (INSTANCE == null) {
+            INSTANCE = new BookshelfImpl();
+            INSTANCE.init();
+        }
+        return INSTANCE;
+    }
+
+    @Override
+    public Book findByTitle(String title) {
+        return this.stream()
+          .filter(book -> book.getTitle().toLowerCase().contains(title.toLowerCase()))
+          .findFirst()
+          .orElse(null);
+    }
+}

patterns/front-controller/src/main/resources/front controller.puml

@@ -0,0 +1,22 @@
+@startuml
+
+class Handler {
+doGet
+doPost
+}
+
+abstract class AbstractCommand {
+process
+}
+class ConcreteCommand1 {
+process
+}
+class ConcreteCommand2 {
+process
+}
+
+Handler .right.> AbstractCommand
+AbstractCommand <|-- ConcreteCommand1
+AbstractCommand <|-- ConcreteCommand2
+
+@enduml

patterns/front-controller/src/main/webapp/WEB-INF/jsp/book-found.jsp

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Bookshelf: Title found</title>
+    </head>
+    <body>
+        <p>Our Bookshelf contains this title:</p>
+        <h2>${book.getTitle()}</h2>
+        <p>Author: ${book.getAuthor()}</p>
+        <input type="submit" value="Buy it: ${book.getPrice()}$">
+    </body>
+</html>

patterns/front-controller/src/main/webapp/WEB-INF/jsp/book-notfound.jsp

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Bookshelf: Title not found</title>
+</head>
+    <body>
+        <p>Our Bookshelf doesn't contains this title:</p>
+        <h2>${param.get("title")}</h2>
+    </body>
+</html>

patterns/front-controller/src/main/webapp/WEB-INF/jsp/unknown.jsp

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Bookshelf: Command unknown</title>
+    </head>
+    <body>
+        <p>Sorry, this command is not known!</p>
+    </body>
+</html>

patterns/front-controller/src/main/webapp/WEB-INF/web.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
+		   http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
+         version="3.1">
+    <servlet>
+        <servlet-name>front-controller</servlet-name>
+        <servlet-class>com.baeldung.patterns.front.controller.FrontControllerServlet</servlet-class>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>front-controller</servlet-name>
+        <url-pattern>/</url-pattern>
+    </servlet-mapping>
+</web-app>

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/FrontControllerServlet.java

@@ -1,9 +1,9 @@
-package com.baeldung.patterns;
+package com.baeldung.patterns.intercepting.filter;
 
-import com.baeldung.patterns.commands.FrontCommand;
+import com.baeldung.patterns.intercepting.filter.commands.FrontCommand;
-import com.baeldung.patterns.commands.UnknownCommand;
+import com.baeldung.patterns.intercepting.filter.commands.UnknownCommand;
-import com.baeldung.patterns.data.Bookshelf;
+import com.baeldung.patterns.intercepting.filter.data.Bookshelf;
-import com.baeldung.patterns.data.BookshelfImpl;
+import com.baeldung.patterns.intercepting.filter.data.BookshelfImpl;
 
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
@@ -13,7 +13,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 
-@WebServlet(name = "front-controller", urlPatterns = "/index")
+@WebServlet(name = "intercepting-filter", urlPatterns = "/")
 public class FrontControllerServlet extends HttpServlet {
     @Override
     public void init(ServletConfig config) throws ServletException {
@@ -52,7 +52,7 @@ public class FrontControllerServlet extends HttpServlet {
         try {
             Class type = Class.forName(
               String.format(
-                "com.baeldung.patterns.commands.%sCommand",
+                "com.baeldung.patterns.intercepting.filter.commands.%sCommand",
                 request.getParameter("command")
               )
             );

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/CheckoutCommand.java

@@ -1,6 +1,6 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.data.Order;
+import com.baeldung.patterns.intercepting.filter.data.Order;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpSession;
@@ -13,7 +13,7 @@ public class CheckoutCommand extends FrontCommand {
         HttpSession session = request.getSession(false);
         if (request.getMethod().equals("POST")) {
             session.removeAttribute("order");
-            response.sendRedirect("index?command=Home&message=Thank you for buying!");
+            response.sendRedirect("/?command=Home&message=Thank you for buying!");
         } else {
             Order order = (Order) session.getAttribute("order");
             Double total = order.getItems().entrySet().stream()

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/FrontCommand.java

@@ -1,7 +1,7 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.filters.FilterManager;
+import com.baeldung.patterns.intercepting.filter.filters.FilterManager;
-import com.baeldung.patterns.filters.OnIntercept;
+import com.baeldung.patterns.intercepting.filter.filters.OnIntercept;
 
 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/HomeCommand.java

@@ -1,6 +1,6 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.data.Bookshelf;
+import com.baeldung.patterns.intercepting.filter.data.Bookshelf;
 
 import javax.servlet.ServletException;
 import java.io.IOException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/LoginCommand.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpSession;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/LogoutCommand.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpSession;
@@ -11,6 +11,6 @@ public class LogoutCommand extends FrontCommand {
         HttpSession session = request.getSession(false);
         session.removeAttribute("username");
         session.removeAttribute("order");
-        response.sendRedirect("index?command=Home");
+        response.sendRedirect("/?command=Home");
     }
 }

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/OrderCommand.java

@@ -1,9 +1,9 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.data.Book;
+import com.baeldung.patterns.intercepting.filter.data.Book;
-import com.baeldung.patterns.data.Bookshelf;
+import com.baeldung.patterns.intercepting.filter.data.Bookshelf;
-import com.baeldung.patterns.data.Order;
+import com.baeldung.patterns.intercepting.filter.data.Order;
-import com.baeldung.patterns.data.OrderImpl;
+import com.baeldung.patterns.intercepting.filter.data.OrderImpl;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpSession;
@@ -27,7 +27,7 @@ public class OrderCommand extends FrontCommand {
             Book book = bookshelf.get(isbn);
             order.add(book, quantity);
             session.setAttribute("order", order);
-            response.sendRedirect(String.format("index?command=Show&isbn=%s", isbn));
+            response.sendRedirect(String.format("/?command=Show&isbn=%s", isbn));
         }
     }
 }

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/SearchCommand.java

@@ -1,7 +1,7 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.data.Book;
+import com.baeldung.patterns.intercepting.filter.data.Book;
-import com.baeldung.patterns.data.Bookshelf;
+import com.baeldung.patterns.intercepting.filter.data.Bookshelf;
 
 import javax.servlet.ServletException;
 import java.io.IOException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/ShowCommand.java

@@ -1,7 +1,7 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
-import com.baeldung.patterns.data.Book;
+import com.baeldung.patterns.intercepting.filter.data.Book;
-import com.baeldung.patterns.data.Bookshelf;
+import com.baeldung.patterns.intercepting.filter.data.Bookshelf;
 
 import javax.servlet.ServletException;
 import java.io.IOException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/commands/UnknownCommand.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.commands;
+package com.baeldung.patterns.intercepting.filter.commands;
 
 import javax.servlet.ServletException;
 import java.io.IOException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/Book.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 public interface Book {
     String getIsbn();

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/BookImpl.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 public class BookImpl implements Book {
     private String isbn;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/Bookshelf.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 import java.util.List;
 

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/BookshelfImpl.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 import java.util.ArrayList;
 import java.util.List;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/Order.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 import java.util.Map;
 

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/data/OrderImpl.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.data;
+package com.baeldung.patterns.intercepting.filter.data;
 
 import java.util.HashMap;
 import java.util.Map;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/AuthenticationFilter.java

@@ -1,7 +1,7 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
-import com.baeldung.patterns.commands.FrontCommand;
+import com.baeldung.patterns.intercepting.filter.commands.FrontCommand;
-import com.baeldung.patterns.commands.LoginCommand;
+import com.baeldung.patterns.intercepting.filter.commands.LoginCommand;
 
 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/BaseFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/EncodingFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import javax.servlet.*;
 import javax.servlet.annotation.WebFilter;
@@ -6,7 +6,7 @@ import javax.servlet.annotation.WebInitParam;
 import java.io.IOException;
 
 @WebFilter(
-  servletNames = {"front-controller"},
+  servletNames = {"intercepting-filter"},
   initParams = {@WebInitParam(name = "encoding", value = "UTF-8")}
 )
 public class EncodingFilter extends BaseFilter {

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/FilterChainImpl.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import javax.servlet.*;
 import java.io.IOException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/FilterManager.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/LoggingFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -11,7 +11,7 @@ import javax.servlet.annotation.WebFilter;
 import javax.servlet.http.HttpServletRequest;
 import java.io.IOException;
 
-@WebFilter(servletNames = "front-controller")
+@WebFilter(servletNames = "intercepting-filter")
 public class LoggingFilter extends BaseFilter {
     private static final Logger log = LoggerFactory.getLogger(LoggingFilter.class);
 

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/OnIntercept.java

@@ -0,0 +1,5 @@
+package com.baeldung.patterns.intercepting.filter.filters;
+
+public interface OnIntercept {
+    void intercept();
+}

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/TemplateFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;

patterns/intercepting-filter/src/main/java/com/baeldung/patterns/intercepting/filter/filters/VisitorCounterFilter.java

@@ -1,4 +1,4 @@
-package com.baeldung.patterns.filters;
+package com.baeldung.patterns.intercepting.filter.filters;
 
 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/book-found.jsp

@@ -1,4 +1,4 @@
-<%@ page import="com.baeldung.patterns.data.Book" %>
+<%@ page import="com.baeldung.patterns.intercepting.filter.data.Book" %>
 <%@ page import="java.util.List" %>
 <!DOCTYPE html>
 <html>
@@ -10,12 +10,12 @@
         <% for (Book book : (List<Book>) request.getAttribute("books")) { %>
             <h2><%= book.getTitle() %></h2>
             <p>Author: <%= book.getAuthor() %></p>
-            <form action="index?command=Order" method="POST">
+            <form action="/?command=Order" method="POST">
                 <label for="quantity">Quantity:</label>
                 <input type="text" id="quantity" name="quantity" value="1" required>
                 <input type="hidden" name="isbn" value="<%= book.getIsbn() %>">
                 <input type="submit" value="Buy it: <%= book.getPrice() %>$">
-                <a href="index?command=Home">Go back...</a>
+                <a href="/?command=Home">Go back...</a>
             </form>
         <% } %>
         <%@ include file="shopping-cart-hint.jsp"%>

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/home.jsp

@@ -1,4 +1,4 @@
-<%@ page import="com.baeldung.patterns.data.Book" %>
+<%@ page import="com.baeldung.patterns.intercepting.filter.data.Book" %>
 <%@ page import="java.util.List" %>
 <!DOCTYPE>
 <html>
@@ -6,7 +6,7 @@
         <title>Bookshelf: Home</title>
     </head>
     <body>
-        <form action="index?command=Search" method="POST">
+        <form action="/?command=Search" method="POST">
             <input type="text" id="search" name="q">
             <input type="submit" value="Go!">
         </form>
@@ -19,7 +19,7 @@
             <hr/>
             <p><b><%= book.getAuthor() %>:</b></p>
             <h3><%= book.getTitle() %></h3>
-            <a href="index?command=Show&isbn=<%= book.getIsbn() %>">More...</a>
+            <a href="/?command=Show&isbn=<%= book.getIsbn() %>">More...</a>
         <% } %>
         <%@ include file="shopping-cart-hint.jsp"%>
         <%@ include file="visitor-counter.jsp"%>

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/login.jsp

@@ -6,7 +6,7 @@
     <body>
         <p>Please input a username:</p>
         <h2>Login</h2>
-        <form action="index?command=Login" method="POST">
+        <form action="/?command=Login" method="POST">
             <input type="text" name="username" placeholder="Username">
             <input type="hidden" name="redirect" value="<%= (String) request.getAttribute("redirect") %>">
             <input type="submit" value="Proceed">

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/shopping-cart-hint.jsp

@@ -1,4 +1,4 @@
-<%@ page import="com.baeldung.patterns.data.Order" %>
+<%@ page import="com.baeldung.patterns.intercepting.filter.data.Order" %>
 <% if (session != null && session.getAttribute("order") != null) { %>
     <% Order order = ((Order) session.getAttribute("order")); %>
     <% if (order != null && order.getItems().size() > 0) { %>
@@ -10,7 +10,7 @@
             <% } else { %>
                 <%= (order.getItems().size()) %> items.
             <% } %>
-            <a href="index?command=Checkout">Checkout</a>
+            <a href="/?command=Checkout">Checkout</a>
         </p>
     <% } %>
 <% } %>

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/shopping-cart.jsp

@@ -1,5 +1,5 @@
-<%@ page import="com.baeldung.patterns.data.Book" %>
+<%@ page import="com.baeldung.patterns.intercepting.filter.data.Book" %>
-<%@ page import="com.baeldung.patterns.data.Order" %>
+<%@ page import="com.baeldung.patterns.intercepting.filter.data.Order" %>
 <%@ page import="java.util.Map" %>
 <!DOCTYPE html>
 <html>
@@ -22,7 +22,7 @@
         <p>
             <b>Total: <%= request.getAttribute("total") %></b>
         </p>
-        <form action="index?command=Checkout" method="POST">
+        <form action="/?command=Checkout" method="POST">
             <input type="submit" value="Donate :)">
         </form>
     </body>

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/unknown.jsp

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Bookshelf: Command unknown</title>
+    </head>
+    <body>
+        <p>Sorry, this command is not known!</p>
+    </body>
+</html>

patterns/intercepting-filter/src/main/webapp/WEB-INF/jsp/visitor-counter.jsp

@@ -1,5 +1,5 @@
 <% Integer counter = (Integer) request.getAttribute("counter"); %>
 <% if (counter != null && counter > 0) { %>
     <hr/>
-    <p>You are visitor #<%= counter %>. <a href="index?command=Logout">Logout</a></p>
+    <p>You are visitor #<%= counter %>. <a href="/?command=Logout">Logout</a></p>
 <% } %>

patterns/pom.xml

@@ -4,16 +4,22 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
+    <groupId>com.baeldung.patterns</groupId>
+    <artifactId>patterns-parent</artifactId>
+    <packaging>pom</packaging>
+    <modules>
+        <module>front-controller</module>
+        <module>intercepting-filter</module>
+    </modules>
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
+        <relativePath>..</relativePath>
     </parent>
 
-    <groupId>com.baeldung.patterns</groupId>
+    <dependencyManagement>
-    <artifactId>patterns</artifactId>
-    <packaging>war</packaging>
-
         <dependencies>
             <dependency>
                 <groupId>javax.servlet</groupId>
@@ -21,15 +27,11 @@
                 <version>3.1.0</version>
                 <scope>provided</scope>
             </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-api</artifactId>
-            <version>1.7.21</version>
-            <scope>provided</scope>
-        </dependency>
         </dependencies>
+    </dependencyManagement>
 
     <build>
+        <pluginManagement>
             <plugins>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
@@ -44,20 +46,13 @@
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-war-plugin</artifactId>
                     <version>3.0.0</version>
-                <configuration>
-                    <failOnMissingWebXml>false</failOnMissingWebXml>
-                </configuration>
                 </plugin>
                 <plugin>
                     <groupId>org.eclipse.jetty</groupId>
                     <artifactId>jetty-maven-plugin</artifactId>
-                <version>9.3.11.v20160721</version>
+                    <version>9.3.12.v20160915</version>
-                <configuration>
-                    <webApp>
-                        <contextPath>/</contextPath>
-                    </webApp>
-                </configuration>
                 </plugin>
             </plugins>
+        </pluginManagement>
     </build>
 </project>

patterns/src/main/java/com/baeldung/patterns/filters/OnIntercept.java

@@ -1,5 +0,0 @@
-package com.baeldung.patterns.filters;
-
-public interface OnIntercept {
-    void intercept();
-}