Java Design Patterns Chain of Responsibility Patterns Example 1

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;



interface Language {
   public String getFirstName();
}

class LanguageImpl implements Language {
   private String firstName;

   public LanguageImpl() {
   }//from   w ww.  ja v  a2  s  .  co  m

   public LanguageImpl(String newFirstName) {
      firstName = newFirstName;
   }

   public String getFirstName() {
      return firstName;
   }

   public void setFirstName(String newFirstName) {
      firstName = newFirstName;
   }
   public String toString() {
      return firstName;
   }
}

class Project implements TaskItem {
   private String name;
   private Language lang;
   private String details;
   private List projectItems = new ArrayList();

   public Project() {
   }

   public Project(String n, Language l) {
      name = n;
      lang = l;
   }

   public String getName() {
      return name;
   }

   public String getDetails() {
      return details;
   }

   public Language getLanguage() {
      return lang;
   }

   public TaskItem getParent() {
      return null;
   }

   public List getTaskItems() {
      return projectItems;
   }

   public void setName(String newName) {
      name = newName;
   }

   public void setOwner(Language newOwner) {
      lang = newOwner;
   }

   public void setDetails(String newDetails) {
      details = newDetails;
   }

   public void addTaskItem(TaskItem element) {
      if (!projectItems.contains(element)) {
         projectItems.add(element);
      }
   }

   public void removeTaskItem(TaskItem element) {
      projectItems.remove(element);
   }

   public String toString() {
      return name;
   }
}

interface TaskItem {
   public TaskItem getParent();

   public Language getLanguage();

   public List getTaskItems();
}

class Task implements TaskItem {
   private String name;
   private List projectItems = new ArrayList();
   private Language owner;
   private TaskItem parent;
   private boolean primaryTask;

   public Task(TaskItem newParent) {
      this(newParent, "", null, false);
   }

   public Task(TaskItem newParent, String newName, Language newOwner, boolean newPrimaryTask) {
      parent = newParent;
      name = newName;
      owner = newOwner;
      primaryTask = newPrimaryTask;
   }

   public Language getLanguage() {
      if (owner == null) {
         return parent.getLanguage();
      } else {
         return owner;
      }
   }

   public String getName() {
      return name;
   }

   public List getTaskItems() {
      return projectItems;
   }

   public TaskItem getParent() {
      return parent;
   }

   public boolean isPrimaryTask() {
      return primaryTask;
   }

   public void setName(String newName) {
      name = newName;
   }

   public void setOwner(Language newOwner) {
      owner = newOwner;
   }

   public void setParent(TaskItem newParent) {
      parent = newParent;
   }

   public void setPrimaryTask(boolean newPrimaryTask) {
      primaryTask = newPrimaryTask;
   }

   public void addTaskItem(TaskItem element) {
      if (!projectItems.contains(element)) {
         projectItems.add(element);
      }
   }

   public void removeTaskItem(TaskItem element) {
      projectItems.remove(element);
   }

   public String toString() {
      return name;
   }
}

public class Main {
   public static void main(String[] arguments) {
      Project project = createData();

      getItemInfo(project);
   }

   static Project createData() {
      Language contact1 = new LanguageImpl("CSS");
      Language contact2 = new LanguageImpl("HTML");
      Language contact3 = new LanguageImpl("Java");
      Language contact4 = new LanguageImpl("Javascript");

      Project project = new Project("Project A",  contact2);

      Task task1 = new Task(project, "Task 1", contact4, true);
      Task task2 = new Task(project, "Task 2", null, true);
      Task task3 = new Task(project, "Task 3", contact3, false);
      project.addTaskItem(task1);
      project.addTaskItem(task2);
      project.addTaskItem(task3);

      Task task4 = new Task(task1, "Task 4", null, false);
      Task task5 = new Task(task1, "Task 5", contact1, true);
      Task task6 = new Task(task2, "Task 6", contact1,true);
      Task task7 = new Task(task2, "Task 7", null, false);
      Task task8 = new Task(task2, "Task 8", null, false);
      Task task9 = new Task(task3, "Task 9", null, true);
      Task task10 = new Task(task3, "Task 10", contact4, false);
      task1.addTaskItem(task4);
      task1.addTaskItem(task5);
      task2.addTaskItem(task6);
      task2.addTaskItem(task7);
      task2.addTaskItem(task8);
      task3.addTaskItem(task9);
      task3.addTaskItem(task10);
      return project;
   }

   private static void getItemInfo(TaskItem item) {
      System.out.println("TaskItem: " + item);
      System.out.println("  Owner: " + item.getLanguage());
      System.out.println();
      if (item.getTaskItems() != null) {
         Iterator subElements = item.getTaskItems().iterator();
         while (subElements.hasNext()) {
            getItemInfo((TaskItem) subElements.next());
         }
      }
   }
}