Mega Code Archive
Composite Pattern 2
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//[C] 2002 Sun Microsystems, Inc.---
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
public class RunCompositePattern {
public static void main(String [] arguments){
System.out.println("Example for the Composite pattern");
System.out.println();
System.out.println("This code sample will propagate a method call throughout");
System.out.println(" a tree structure. The tree represents a project, and is");
System.out.println(" composed of three kinds of ProjectItems - Project, Task,");
System.out.println(" and Deliverable. Of these three classes, Project and Task");
System.out.println(" can store an ArrayList of ProjectItems. This means that");
System.out.println(" they can act as branch nodes for our tree. The Deliverable");
System.out.println(" is a terminal node, since it cannot hold any ProjectItems.");
System.out.println();
System.out.println("In this example, the method defined by ProjectItem,");
System.out.println(" getTimeRequired, provides the method to demonstrate the");
System.out.println(" pattern. For branch nodes, the method will be passed on");
System.out.println(" to the children. For terminal nodes (Deliverables), a");
System.out.println(" single value will be returned.");
System.out.println();
System.out.println("Note that it is possible to make this method call ANYWHERE");
System.out.println(" in the tree, since all classes implement the getTimeRequired");
System.out.println(" method. This means that you are able to calculate the time");
System.out.println(" required to complete the whole project OR any part of it.");
System.out.println();
System.out.println("Deserializing a test Project for the Composite pattern");
System.out.println();
if (!(new File("data.ser").exists())){
DataCreator.serialize("data.ser");
}
Project project = (Project)(DataRetriever.deserializeData("data.ser"));
System.out.println("Calculating total time estimate for the project");
System.out.println("\t" + project.getDescription());
System.out.println("Time Required: " + project.getTimeRequired());
}
}
interface Contact extends Serializable{
public static final String SPACE = " ";
public String getFirstName();
public String getLastName();
public String getTitle();
public String getOrganization();
public void setFirstName(String newFirstName);
public void setLastName(String newLastName);
public void setTitle(String newTitle);
public void setOrganization(String newOrganization);
}
class ContactImpl implements Contact{
private String firstName;
private String lastName;
private String title;
private String organization;
public ContactImpl(){}
public ContactImpl(String newFirstName, String newLastName,
String newTitle, String newOrganization){
firstName = newFirstName;
lastName = newLastName;
title = newTitle;
organization = newOrganization;
}
public String getFirstName(){ return firstName; }
public String getLastName(){ return lastName; }
public String getTitle(){ return title; }
public String getOrganization(){ return organization; }
public void setFirstName(String newFirstName){ firstName = newFirstName; }
public void setLastName(String newLastName){ lastName = newLastName; }
public void setTitle(String newTitle){ title = newTitle; }
public void setOrganization(String newOrganization){ organization = newOrganization; }
public String toString(){
return firstName + SPACE + lastName;
}
}
class DataCreator{
private static final String DEFAULT_FILE = "data.ser";
public static void main(String [] args){
String fileName;
if (args.length == 1){
fileName = args[0];
}
else{
fileName = DEFAULT_FILE;
}
serialize(fileName);
}
public static void serialize(String fileName){
try{
serializeToFile(createData(), fileName);
}
catch (IOException exc){
exc.printStackTrace();
}
}
private static Serializable createData(){
Contact contact1 = new ContactImpl("Dennis", "Moore", "Managing Director", "Highway Man, LTD");
Contact contact2 = new ContactImpl("Joseph", "Mongolfier", "High Flyer", "Lighter than Air Productions");
Contact contact3 = new ContactImpl("Erik", "Njoll", "Nomad without Portfolio", "Nordic Trek, Inc.");
Contact contact4 = new ContactImpl("Lemming", "", "Principal Investigator", "BDA");
Project project = new Project("IslandParadise", "Acquire a personal island paradise");
Deliverable deliverable1 = new Deliverable("Island Paradise", "", contact1);
Task task1 = new Task("Fortune", "Acquire a small fortune", contact4, 11.0);
Task task2 = new Task("Isle", "Locate an island for sale", contact2, 7.5);
Task task3 = new Task("Name", "Decide on a name for the island", contact3, 3.2);
project.addProjectItem(deliverable1);
project.addProjectItem(task1);
project.addProjectItem(task2);
project.addProjectItem(task3);
Deliverable deliverable11 = new Deliverable("$1,000,000", "(total net worth after taxes)", contact1);
Task task11 = new Task("Fortune1", "Use psychic hotline to predict winning lottery numbers", contact4, 2.5);
Task task12 = new Task("Fortune2", "Invest winnings to ensure 50% annual interest", contact1, 14.0);
task1.addProjectItem(task11);
task1.addProjectItem(task12);
task1.addProjectItem(deliverable11);
Task task21 = new Task("Isle1", "Research whether climate is better in the Atlantic or Pacific", contact1, 1.8);
Task task22 = new Task("Isle2", "Locate an island for auction on EBay", contact4, 5.0);
Task task23 = new Task("Isle2a", "Negotiate for sale of the island", contact3, 17.5);
task2.addProjectItem(task21);
task2.addProjectItem(task22);
task2.addProjectItem(task23);
Deliverable deliverable31 = new Deliverable("Island Name", "", contact1);
task3.addProjectItem(deliverable31);
return project;
}
private static void serializeToFile(Serializable content, String fileName) throws IOException{
ObjectOutputStream serOut = new ObjectOutputStream(new FileOutputStream(fileName));
serOut.writeObject(content);
serOut.close();
}
}
class DataRetriever{
public static Object deserializeData(String fileName){
Object returnValue = null;
try{
File inputFile = new File(fileName);
if (inputFile.exists() && inputFile.isFile()){
ObjectInputStream readIn = new ObjectInputStream(new FileInputStream(fileName));
returnValue = readIn.readObject();
readIn.close();
}else{
System.err.println("Unable to locate the file " + fileName);
}
}catch (ClassNotFoundException exc){
exc.printStackTrace();
}catch (IOException exc){
exc.printStackTrace();
}
return returnValue;
}
}
class Deliverable implements ProjectItem{
private String name;
private String description;
private Contact owner;
public Deliverable(){ }
public Deliverable(String newName, String newDescription,
Contact newOwner){
name = newName;
description = newDescription;
owner = newOwner;
}
public String getName(){ return name; }
public String getDescription(){ return description; }
public Contact getOwner(){ return owner; }
public double getTimeRequired(){ return 0; }
public void setName(String newName){ name = newName; }
public void setDescription(String newDescription){ description = newDescription; }
public void setOwner(Contact newOwner){ owner = newOwner; }
}
class Project implements ProjectItem{
private String name;
private String description;
private ArrayList projectItems = new ArrayList();
public Project(){ }
public Project(String newName, String newDescription){
name = newName;
description = newDescription;
}
public String getName(){ return name; }
public String getDescription(){ return description; }
public ArrayList getProjectItems(){ return projectItems; }
public double getTimeRequired(){
double totalTime = 0;
Iterator items = projectItems.iterator();
while(items.hasNext()){
ProjectItem item = (ProjectItem)items.next();
totalTime += item.getTimeRequired();
}
return totalTime;
}
public void setName(String newName){ name = newName; }
public void setDescription(String newDescription){ description = newDescription; }
public void addProjectItem(ProjectItem element){
if (!projectItems.contains(element)){
projectItems.add(element);
}
}
public void removeProjectItem(ProjectItem element){
projectItems.remove(element);
}
}
interface ProjectItem extends Serializable{
public double getTimeRequired();
}
class Task implements ProjectItem{
private String name;
private String details;
private ArrayList projectItems = new ArrayList();
private Contact owner;
private double timeRequired;
public Task(){ }
public Task(String newName, String newDetails,
Contact newOwner, double newTimeRequired){
name = newName;
details = newDetails;
owner = newOwner;
timeRequired = newTimeRequired;
}
public String getName(){ return name; }
public String getDetails(){ return details; }
public ArrayList getProjectItems(){ return projectItems; }
public Contact getOwner(){ return owner; }
public double getTimeRequired(){
double totalTime = timeRequired;
Iterator items = projectItems.iterator();
while(items.hasNext()){
ProjectItem item = (ProjectItem)items.next();
totalTime += item.getTimeRequired();
}
return totalTime;
}
public void setName(String newName){ name = newName; }
public void setDetails(String newDetails){ details = newDetails; }
public void setOwner(Contact newOwner){ owner = newOwner; }
public void setTimeRequired(double newTimeRequired){ timeRequired = newTimeRequired; }
public void addProjectItem(ProjectItem element){
if (!projectItems.contains(element)){
projectItems.add(element);
}
}
public void removeProjectItem(ProjectItem element){
projectItems.remove(element);
}
}
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