Java vs. .NET

1
Java vs. .NET

• Java vs. C
• Swing vs. WinForms

2
C Language Differences

• Class Declaration
• .NET Types
• Event Handling
• Exception Handling
• Operation Parameters
• Operation Visibility

• Component Assemblies
• Package Structure
• Class Properties and Structures
• Class Indexers
• Source Code Attributes

3
Class Declaration

• class SomeClass ExtendedClass, Interface1,
  Interface2
• SomeClass extends ExtendedClass
• SomeClass implements Interface1 and Inteface2
• More than one object can be declared inside the
  .cs file

4
Package Structure

• To import use using keyword

5
.NET Types

• Value Types can be used as Objects
• Aliased to System types so that any .NET language
  can use them from any other .NET language
• (See column to the right) ?
• Structures
• Can have constructors

• Java boolean
• bool (System.Boolean)
• Java bytes
• byte (System.Sbyte)
• Java char
• char (System.Char)
• Java int
• int (System.Int32)
• Java long
• long (System.Int64)
• Java float
• float (System.Single)
• Java double
• double (System.Double)

6
Exception Handling

• Catch Block can trap no Exception or specific
  Exceptions

7
Event Handling

• .NET Delegates
• Much different than Java

8
Class Properties

• Declare a variable
• Only a getter implies a read-only property
• Can use lazy initialization
• Can be defined in an Interface

9
Class Indexers

• Instances of a class can be referenced with Array
  notation on the class

10
Operation Parameters

• Undetermined Number of Parameters
• public void methodCaller( params int a )
• methodCaller( 1 )
• methodCaller( 1, 2, 3, 4, 5 )
• Pass by Reference
• public void increment( ref int a )
• Can possibly change the value of a
• Pass by Reference and Change Value
• public void DoNothing( out int a )
• Ensures a is changed

11
Operation Visibility

• Overriding Inherited Operations
• Requires superclass method to be marked virtual
• Overriding method must be marked override
• public, protected, and private are the same as in
  Java
• internal
• Member is accessible from the entire assembly.
• More than one object can be declared inside the
  .cs file.
• Each object has a handle to the internal member
• protected internal
• A union of protected and internal.
• Can be accessed from the entire assembly, or
  within objects which derive from this class

12
Component Assemblies

• Common Language Runtime (CLR)
• Similar to Java VM
• But multi-lingual, i.e. VB, C, C
• Shareable Dynamic Link Libraries
• Shareable Code Modules
• Linked at compile-time
• Transparency to all .NET languages
• Should be aware of data types, naming and
  formatting standards

13
Source Code Attributes

• Used for compiler and runtime processing
• Attributes are derived from System.Attribute
• New and confusing for us Java Developers

14
Swing and WinForms

• .NET has the same GUI components as Swing
• No Layout Managers
• .NET has Data Binding!
• DataProvider manages DataSources
• DataSet is a disconnected, in-memory data cache
• Lots of 3rd Party Controls converted from COM
  Components to .NET
• Especially Tables and 2D Graphs
• Extensible Application Markup Language (XAML)

15
IDEs

• Visual Studio
• Requires .NET Framework install first
• Horrendously lengthy installation
• SharpDevelop
• Open Source
• Improve C Plugin
• Eclipse
• CodeWright
• By Borland

16
References

• C for Java Developers
• Allen Jones, Adam Freeman
• Microsoft Press
• C Language Pocket Reference
• Peter Dayton, Ben Albahari, Ted Neward
• OReilly Books

• XAML
• C Namespaces Doc
• .NET CodeDom
• GotDotNet
• How Do I?...Common Tasks
• .NET 24/7
• Windows Forms QuickStart Tutorial

17
Conclusions

• More web info for Java than .NET for now
• Longhorn and XAML
• XAML can be translated at run-time for WinForms
  or WebForms
• If Windows is the only client platform for
  deploymentwhy not use .NET?
• Front-end .NET and Back-end Java J2EE?