February 01, 2011
Mark Wielaard: New GPG key.
Finally created a new GPG key using gnupg. The old one was a DSA/1024 bits one and 8 years old. The new one is a RSA/2048 bits one. I will use the new one in the future to sign any release tarballs I might create. pub 2048R/57816A6A 2011-01-29 Key f...
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February 01, 2011
Andrew Hughes: [SECURITY] IcedTea6 1.7.8, 1.8.5, 1.9.5 Released!.
We are pleased to announce a new set of security releases, IcedTea6 1.7.8, IcedTea6 1.8.5 and IcedTea6 1.9.5.
This update contains the following security updates:
The IcedTea project provides a harness to build the source code from OpenJDK6 u...
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The Match Maker Design Pattern - a New Place for the Actions
How to add actions to a system without modifying business objects, add objects without changing actions, and still keep things reusable.
The Match Maker Design Pattern
Tue, 2010-04-27
Michael Bar-Sinai
How to add actions to a system without modifying business objects, add objects without changing actions, and still keep things reusable.
Software systems often deal with similar concepts, whose behavior differs only slightly. Classic Object-Oriented design deals with such cases using inheritance; overriding the calculateSalary() method in different Employee subclasses allows the rest of the application to remain oblivious to the subtle differences between the salary algorithms of Manager, Engineer, and AnnoyingCeoNephew.
Sadly, inheritance doesn't scale very well. You might get away with adding a toXml() method to the business model objects, but when the customer requires data export support for Excel, OpenOffice, CSV, JSON and Lotus 1-2-3 - you know inheritance just ain't gonna cut it. Another issue with inheritance is that when one holds an Employee reference to an object and needs to know the its ac...
Date: April, 26 2010
Url: http://www.java.net/article/2010/04/26/match-maker-design-pattern-new-place-actions
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