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=== Java Example ===
'''Example 1''' -- This code can be found at [http://www.javacamp.org/designPattern/chains.html www.Javacamp.org]
import java.io.*;
abstract class PurchasePower {
protected final double base = 500;
protected PurchasePower successor;
public void setSuccessor(PurchasePower successor){
this.successor = successor;
}
abstract public void processRequest(PurchaseRequest request);
}
class Manager extends PurchasePower {
private final double ALLOWABLE = 10 * base;
public void processRequest(PurchaseRequest request ) {
if( request.getAmount() < ALLOWABLE )
System.out.println("Manager will approve $"+ request.getAmount());
else
if( successor != null)
successor.processRequest(request);
}
}
class Director extends PurchasePower {
private final double ALLOWABLE = 20 * base;
public void processRequest(PurchaseRequest request ) {
if( request.getAmount() < ALLOWABLE )
System.out.println("Director will approve $"+ request.getAmount());
else
if( successor != null)
successor.processRequest(request);
}
}
class VicePresident extends PurchasePower {
private final double ALLOWABLE = 40 * base;
public void processRequest(PurchaseRequest request) {
if( request.getAmount() < ALLOWABLE )
System.out.println("Vice President will approve $" + request.getAmount());
else
if( successor != null )
successor.processRequest(request);
}
}
class President extends PurchasePower {
private final double ALLOWABLE = 60 * base;
public void processRequest(PurchaseRequest request){
if( request.getAmount() < ALLOWABLE )
System.out.println("President will approve $" + request.getAmount());
else
System.out.println( "Your request for $" + request.getAmount() + " needs a board meeting!");
}
}
class PurchaseRequest {
private int number;
private double amount;
private String purpose;
public PurchaseRequest(int number, double amount, String purpose){
this.number = number;
this.amount = amount;
this.purpose = purpose;
}
public double getAmount() {
return amount;
}
public void setAmount(double amt){
amount = amt;
}
public String getPurpose() {
return purpose;
}
public void setPurpose(String reason) {
purpose = reason;
}
public int getNumber(){
return number;
}
public void setNumber(int num) {
number = num;
}
}
class CheckAuthority {
public static void main(String[] args) throws Exception{
Manager manager = new Manager();
Director director = new Director();
VicePresident vp = new VicePresident();
President president = new President();
manager.setSuccessor(director);
director.setSuccessor(vp);
vp.setSuccessor(president);
//enter ctrl+c to kill.
while (true) {
System.out.println("Enter the amount to check who should approve your expenditure.");
System.out.print(">");
double d = Double.parseDouble(new BufferedReader(new InputStreamReader(System.in)).readLine());
manager.processRequest(new PurchaseRequest(0, d, "General"));
}
}
}
----
# [http://codebetter.com/blogs/jeremy.miller/archive/2005/11/06/134359.aspx Codebetter.com]
# [http://www.c-sharpcorner.com/UploadFile/rmcochran/chain_of_command01172007143425PM/chain_of_command.aspx C-Sharpcorner.com]
# [http://www.javacamp.org/designPattern/chains.html Javacamp.org]
----
--[[User:Djeyarat|Djeyarat]] 15:49, 2 April 2007 (EDT)