crystal reports barcode Aspect-oriented Implementation in Font

Encode DataMatrix in Font Aspect-oriented Implementation

Aspect-oriented Implementation
ECC200 Generation In None
Using Barcode drawer for Font Control to generate, create Data Matrix ECC200 image in Font applications.
www.OnBarcode.com
Make Barcode In None
Using Barcode generator for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
The implementation that we propose for the Chain of Responsibility design pattern uses the notion of aspect precedence. In the previously presented design patterns, an abstract aspect was defined to implement the code that was shared by all the commands in a chain. This abstract aspect was then extended for each concrete command. Aspect precedence is the notion used for ordering the execution of these commands in the chain.
PDF417 Maker In None
Using Barcode encoder for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
Drawing QR Code In None
Using Barcode generator for Font Control to generate, create Denso QR Bar Code image in Font applications.
www.OnBarcode.com
Generic Part of the Implementation
Encode Code 39 Full ASCII In None
Using Barcode generator for Font Control to generate, create Code 39 Extended image in Font applications.
www.OnBarcode.com
Making DataMatrix In None
Using Barcode encoder for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
The generic part of our implementation of the Chain of Responsibility design pattern is defined in the AbstractChainAspect abstract aspect shown in Listing 8-17. Listing 8-17. Implementation of the Chain of Responsibility Design Pattern Using AspectJ 1 package aop.patterns.chainOfResponsibility; 2 3 public abstract aspect AbstractChainAspect pertarget(receiver()){ 4 protected abstract pointcut receiver();
Make UPC-A Supplement 5 In None
Using Barcode encoder for Font Control to generate, create UPC A image in Font applications.
www.OnBarcode.com
Royal Mail Barcode Creation In None
Using Barcode creation for Font Control to generate, create British Royal Mail 4-State Customer Barcode image in Font applications.
www.OnBarcode.com
CHAPTER 8 DESIGN PATTERNS AND AOP
ECC200 Encoder In None
Using Barcode drawer for Font Control to generate, create DataMatrix image in Font applications.
www.OnBarcode.com
ECC200 Reader In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
5 6 7 8 9 10 }
Create Code 128A In Java
Using Barcode maker for Android Control to generate, create Code 128 image in Android applications.
www.OnBarcode.com
Barcode Reader In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
protected abstract pointcut execute(); protected abstract void handle(); after() : execute() { handle(); }
PDF-417 2d Barcode Creator In Java
Using Barcode creator for Android Control to generate, create PDF 417 image in Android applications.
www.OnBarcode.com
Linear 1D Barcode Creator In VB.NET
Using Barcode generator for .NET framework Control to generate, create 1D Barcode image in VS .NET applications.
www.OnBarcode.com
With our implementation of the Observer and Command design pattern, the abstract receiver pointcut will designate the objects where the Chain of Responsibility pattern needs to be integrated. The abstract execute pointcut defines the condition, which triggers the execution of the chain. The after advice (line 7) calls the abstract method handle. This method will be concretized into subaspects to define the behavior implemented by each command in the chain.
Generating Code 3 Of 9 In Visual Studio .NET
Using Barcode drawer for ASP.NET Control to generate, create ANSI/AIM Code 39 image in ASP.NET applications.
www.OnBarcode.com
Creating PDF 417 In None
Using Barcode creation for Excel Control to generate, create PDF-417 2d barcode image in Office Excel applications.
www.OnBarcode.com
Implementation of a Chain of Commands
Make QR In VS .NET
Using Barcode generation for Reporting Service Control to generate, create QR Code 2d barcode image in Reporting Service applications.
www.OnBarcode.com
EAN / UCC - 13 Generator In Objective-C
Using Barcode creation for iPhone Control to generate, create GS1-128 image in iPhone applications.
www.OnBarcode.com
We now define two simple commands, Step1ChainAspect and Step2ChainAspect, which will be put in a chain (see Listing 8-18). Listing 8-18. Concrete Aspect to Bind the Chain of Responsibility Design Pattern to the Stats Class 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 package aop.patterns.chainOfResponsibility; public aspect Step1ChainAspect extends AbstractChainAspect { protected pointcut receiver() : initialization(Stats.new(..)); protected pointcut execute() : call(void Stats.incOrders()); protected void handle() { System.out.println("OrderHandler 1"); } } public aspect Step2ChainAspect extends AbstractChainAspect { declare precedence : Step1ChainAspect; protected pointcut receiver() : initialization(Stats.new(..)); protected pointcut execute() : call(void Stats.incOrders()); protected void handle() { System.out.println("OrderHandler 2"); } }
Barcode Creation In None
Using Barcode maker for Office Excel Control to generate, create Barcode image in Office Excel applications.
www.OnBarcode.com
Making Code 128 In Objective-C
Using Barcode generation for iPhone Control to generate, create USS Code 128 image in iPhone applications.
www.OnBarcode.com
Both aspects apply on the instances of the Stats class (see the pointcut receiver on lines 4 and 16). Both are also triggered when the Stat.incOrders method is called (see the pointcut execute on lines 5 and 17).
CHAPTER 8 DESIGN PATTERNS AND AOP
The important point in this example is the use of the declare precedence clause at line 14, which allows the definition of the aspect order in the chain. Here, the aspect Step2ChainAspect will be executed after Step1ChainAspect. The ChainExample class in Listing 8-19 illustrates the usage of our implementation of the Chain of Responsibility design pattern. Listing 8-19. Main Class for Testing the Chain of Responsibility Design Pattern package aop.patterns.chainOfResponsibility; public class ChainExample { public static void main(String[] args) { Stats stats = new Stats(); stats.incOrders(); stats.addAmount(10); stats.incOrders(); stats.addAmount(10); stats.incOrders(); stats.addAmount(10); } } When run, this program displays the following output: OrderHandler OrderHandler OrderHandler OrderHandler OrderHandler OrderHandler n 1 n 2 n 1 n 2 n 1 n 2
Evaluation of the Implementation
With the four criteria defined by Hannemann and Kiczales, we can evaluate our implementation as follows: Locality: The class where the chain of responsibility applies is free from any code related to the management of this pattern. The aspect composition mechanism handles the ordering of commands within a chain. Reusability: The management of the chain is reused systematically. The implementation of any new chain only requires the definition of the new chain elements by extending the abstract aspect. Composition transparency: The aspect is not invasive. The behavior of the classes that receives commands is extended, but not modified.
CHAPTER 8 DESIGN PATTERNS AND AOP
(Un)pluggability: The link between the chain of commands and the receivers is weak. The pointcuts for receivers and executions define precisely where the design pattern must be integrated.
Copyright © OnBarcode.com . All rights reserved.