No Generics for You in Java

Include EAN13 in Java No Generics for You
No Generics for You
GS1 - 13 implement in java
use java ean13 development toinsert ean13 in java
Here comes the funny part. In the Rolodex thought experiment, I asked, Wouldn t it be great if [you could just make this Rolodex class a generic] Remember Because one answer is Maybe, but we ll never know, because you can t. Up through Flash Player 10.1 at least, Vector holds a prized position as the one and only generic in all of ActionScript 3.0. You can t take a sweet data type you created and parameterize the type it uses. Sadly, you will see no parameterized Tree.<T>s or Heap.<T>s. For now at least, it s a special case that exists for performance tuning. Although you can build your own data types that use Vector internally for performance, you won t be able to parameterize them and take advantage of the no-cast no-cost element access that you get with a generic. The thing is, you don t really need generics. Judicious use of interfaces makes a lot more sense than a type parameter in most cases. For example, when you think of it, the Rolodex example is really terrible. How would a Rolodex work that stores emotions Cupcakes don t have phone numbers . . . how would you implement placeCall() when T is Cupcake In reality, you almost always need certain guarantees about the objects you re dealing with, even if it s something as simple as the ability to compare two of them. Nowhere does Flash Player give you a sort function that works on all
Bar Code barcode library in java
using java tointegrate bar code for web,windows application
9: Vectors
Barcode recognizer with java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
objects. In other words, your ability to do interesting things generically is limited by the things that you re guaranteed you can do with any arbitrary object. In Flash Player, any arbitrary object means subclasses of Object, and Object is not endowed with many powers. In this case, you really don t want to be able to give Rolodex any type in the world. You want it to operate on objects that have phone numbers to call and a name to sort. Hey, you have a mechanism for that:
Control upc - 13 size in visual
to connect ean13+5 and ean13+2 data, size, image with .net c# barcode sdk
interface IContact { function get phoneNumber():Number; function get fullName():String; function get lastName():String; }
Control ean13 image for .net
generate, create ean-13 supplement 2 none for .net projects
The Rolodex example is far from generic. It should be implemented to only operate on objects that have certain properties. The perfect device for holding objects to a certain contract is an interface. So Rolodex should not be generic. Its interface should be written around an IContact interface that allows it to do the interesting things a Rolodex does. Internally, you re more than welcome to use a Vector.<IContact> to make Rolodex fast and ef cient! (See Example 9-2.) You should use an interface or a common superclass in lieu of generics to keep your classes abstract. The only drawback you ll see is that you may have to do some potentially dangerous upcasts. EXAMPLE 9-2
Ean13+2 barcode library on .net
use vs .net gtin - 13 encoding toget upc - 13 for .net
Control ean13 data for visual basic
ean13 data with visual basic
The Rolodex Class
Control barcode pdf417 size with java
to draw pdf417 and pdf417 data, size, image with java barcode sdk
package { import com.actionscriptbible.Example; public class ch9ex2 extends Example { public function ch9ex2() { var rolodex:Rolodex = new Rolodex(); rolodex.addEntry(new Person("Roger", "Braunstein", 7185555555)); rolodex.addEntry(new Person("Simon", "Bolivar")); rolodex.addEntry(new Person("Shimon", "Peres")); trace("B entries:", rolodex.getEntriesUnderLetter("B")); var firstB:Person = Person(rolodex.getEntriesUnderLetter("B")[0]); //note that we still have to upcast because this returns an IContact. } } } class Rolodex { protected var entries:Vector.<IContact>; public function Rolodex() { entries = new Vector.<IContact>(); } public function addEntry(contact:IContact):void { entries.push(contact); entries = entries.sort(function(a:IContact, b:IContact):Number { return (a.lastName.toLowerCase() < b.lastName.toLowerCase()) -1 : 1; }); }
Java gtin - 12 implementation in java
use java upc-a supplement 2 development topaint upc-a with java
Control gtin - 13 data for java
to generate ean13+5 and gtin - 13 data, size, image with java barcode sdk
Part II: Core ActionScript 3.0 Data Types
Control pdf417 data on java
pdf-417 2d barcode data in java
Control barcode pdf417 image in java
using java touse barcode pdf417 in web,windows application
ISBN - 10 barcode library in java
using java touse bookland ean on web,windows application
public function getEntriesUnderLetter(ltr:String):Vector.<IContact> { ltr = ltr.toLowerCase(); return entries.filter(function(entry:IContact, { return (entry.lastName.charAt(0).toLowerCase() == ltr); }); } public function getRandomEntry():IContact { return entries[Math.floor(Math.random() * entries.length)]; } public function placeCall(contact:IContact):void { trace("calling", contact.phoneNumber); } } interface IContact { function get phoneNumber():Number; function get fullName():String; function get lastName():String; } class Person implements IContact { private var _phoneNumber:Number; private var _lastName:String; private var _firstName:String; public function Person(first:String, last:String = "", number:Number = 0) { _firstName = first; _lastName = last; _phoneNumber = number; } public function get phoneNumber():Number {return _phoneNumber;} public function get fullName():String {return _lastName + ", " + _firstName;} public function get lastName():String {return _lastName;} public function toString():String {return "[Person " + fullName + "]";} }
Control qr bidimensional barcode data with
qr code iso/iec18004 data on visual
Even though I ve designed Rolodex to operate on IContacts, and it uses a Vector for storage internally, you don t have the leisure of returning contacts as type Person or Company; you still have to upcast. Generics are best suited for optimized storage data types, which don t depend in any way on the contents or structure of the data. While you can t create your own, Vector, just like Array, is incredibly useful and exible.
Compose universal product code version a on visual
use .net for windows forms crystal upc-a creation toinclude upc code on c#
Aspx.cs Page Crystal ucc.ean - 128 generator with visual basic
using barcode creator for web pages crystal control to generate, create ucc ean 128 image in web pages crystal applications.
Pdf417 2d Barcode drawer on visual basic
generate, create pdf-417 2d barcode none with projects
EAN / UCC - 14 creation with .net
generate, create gs1128 none with .net projects