Platform Comparison
Java and .NET
Pat Palmer
University of Pennsylvania
10-Nov-11 compare.ppt 1
Java and .NET
• Java was created by Sun in 1992
• Microsoft introduced .NET and C# in 2000
• both platforms are object-oriented, type safe, and have
automatic garbage collection
• the two platforms have been competing vigorously on the
desktop
• but especially in the area of server technology
• many developers become expert on one platform
• few have time to learn both
• the schism of understanding the two platforms widens
• due to misinformation and disinformation
• what are the strengths and issues for each platform?
10-Nov-11 compare.ppt 2
2008 forecast for market share of OS by platform: (2q 06)
Windows 40%
Unix 29%
Linux 15%
Others 16%
forecast market share of OS unit sales: (05)
in 2002 in 2003 in 2007
Windows 45% 59% 59%
Linux 20% 24% 33%
Unix 16% 10% 5%
Others 19% 7% 3%
market share of server shipments by platform in 2005:
Windows 65.6%
Linux 20.0%
Unix 9.5%
NetWare 4.2%
Others 0.7%
FROM: InfoTech Trends http://www.infotechtrends.com/
report from 2Q 2006, accessed on 4/8/2007
10-Nov-11 compare.ppt 3
main sections
1. simple programs
2. overview of platforms
3. why did Sun do it?
4. why did Microsoft do it?
5. Service Oriented Architecture – the peacemaker?
10-Nov-11 compare.ppt 4
1 simple programs
10-Nov-11 compare.ppt 5
console programs
// Java
public class Hello {
public static void main(String[] args) {
System.out.println("Hello world in Java");
}
}
// C#
namespace Hello {
public class Hello {
static void Main(string[] args) {
System.Console.WriteLine ("Hello world in C#");
System.Console.ReadLine();
}
}
}
„ VB
Module HelloWorld
Sub Main
System.Console.WriteLine(“Hello World in VB.NET”)
System.Console.ReadLine()
End Sub
End Module
10-Nov-11 compare.ppt 6
how much work is it to get this?
10-Nov-11 compare.ppt 7
mininal window
import java.awt.*;
import javax.swing.*;
public class Hello extends JFrame implements Runnable
{ using System.Windows.Forms;
namespace TinyWindowApp
public static void main(String[] args) {
{ public class HelloForm : Form
SwingUtilities.invokeLater(new Hello()); {
} static void Main()
{
public void run() Application.Run(new HelloForm());
{ }
this.setSize(new Dimension(200,200));
this.setTitle("Hello in Java"); public HelloForm()
this.setVisible(true); {
} ClientSize = new
} System.Drawing.Size(200, 200);
Text = "Hello in C#";
}
}
}
10-Nov-11 compare.ppt 8
2 overview of platforms
10-Nov-11 compare.ppt 9
identical types of runtime environments
•J2SE (Standard) runtime •C# or VB.NET with VS Express
•desktop applications •desktop application
•J2EE (Enterprise) runtime •IIS with VS Express Web
•web applications •web applications
•J2ME (Micro) runtime •.NET compact framework
•runtime for gadgets •runtime for gadgets
10-Nov-11 compare.ppt 10
Java platform - .NET platform
• Java Virtual Machine (JVM) • Microsoft .NET Framework 2.0
aka Java Runtime Environment (JRE) aka .NET common language runtime (CLR)
• Linux, Windows, Mac and Unix • all versions of Windows (40+)
• download from Sun • download from Microsoft
• JIT compiler and libraries • JIT compiler and libraries
• Java Development Kit (JDK) • NET framework 2.0 SDK
• Java compiler and utilities • C# and VB.NET compilers and utilities
• Java bytecode • Common Intermediate Language (CIL)
• integrated development env. (IDE) • integrated development env. (IDE)
• Eclipse (free - IBM) • Visual Studio Express (free - Microsoft)
• Netbeans (free - Sun) FREE
• application servers • application servers
NOT
• Tomcat • Microsoft Internet Information Server (IIS)
• Glassfish (Sun)
• BEA Weblogic
• IBM Websphere
10-Nov-11 compare.ppt 11
features 1
•virtual machine •virtual machine
•platforms (all major OS’s) •platforms (all versions of Windows)
•spec •spec
•implementations •implementations
•libraries •libraries
•languages •languages
•Java •C#, VB.NET, J# from Microsoft
•Jython •many others from third parties
•Groovy (Haskell, Lisp, Python, COBOL, Fortran, etc.)
•web servers (many vendors) •web servers (just one!)
•platforms (Unix, Linux) •platforms (most Windows)
•scalability •scalability
•cost •cost
•web capabilities •web capabilities
•servlet •handler
•JSP •ASP (.NET)
•JSF •(forgot equivalent name)
10-Nov-11 compare.ppt 12
features 2
•native code calling •native code calling
•components •components
•beans •.DLL
•environments •environments
•applet (in browser) •ActiveX (in browser)
•servlet (in server) •handler (in server)
•Web Start •Smart Client
•installs from web •installs from web
•caches on user’s PC •caches on user’s PC
•deployment •deployment
•.jar •.exe (on file system)
•.war •.exe (in GAC)
•.ear •.dll (on file system)
•.class •all builds and web installation
•complex, painful learning curve is automatically handled by
that differs for each web server, Visual Studio (Microsoft’s IDE)
container, and IDE
•automated via ANT
•XML, like make on Unix
10-Nov-11 compare.ppt 13
features 3
•databases •databases
•JDBC •ODBC
•CORBA •COM
•binary object remoting •binary object remoting
•XML •XML
•via 3rd-party add-ons until Java 6 •excellent support early one
•IDE’s •IDE’s
•Eclipse, with 1000’s of plugins •free versions of Visual Studio
•NetBeans (from Sun) – also free •some third party IDE’s
•service oriented architecture (SOA) •service oriented architecture (SOA)
•annotations appearing •annotations
•web services WS-I •web services WS-I
•supported but difficult (3rd party) •superbly automated by Visual
•new partial automation in Java 6 and Studion since 2005
latest NetBeans IDE
•I haven’t evaluated these yet
10-Nov-11 compare.ppt 14
the JRE and .NET runtimes include lots of libraries
• programs can call a huge body of pre-written code
• these reusable components are called the Class Libraries
• in Java, sometimes they are also called packages or Java API’s
• in .NET, they tend to be called the framework class libraries
• the libraries are designed to be used identically
• in Java, regardless of the underlying operating system
• in .NET, regardless of the underlying version of Windows
OR which language is being used
10-Nov-11 compare.ppt 15
Just in Time (JIT) compilers in JRE (JVM) and .NET runtimes
compilation
source bytecode
code compiler .class file
metadata
before installation,
or the first time
execution each method is
called
native JIT
code Compiler
10-Nov-11 compare.ppt 16
console commands for compiling Java and C#.NET
hello.java hello.cs
javac csc
hello.class hello.exe
1001111010001110 1001111010001110
Java bytecode Common Intermediate Language (CIL)
> java hello > hello.exe assembly
these run in different
virtual machines
10-Nov-11 compare.ppt 17
.NET platform components download free
Software Development
Kit (SDK)
compilers
VB C++ C# J# Python …
web services automation Windows Designer
Microsoft Visual
ASP.NET, IIS Studio .NET
Data and XML
Microsoft .NET
framework class libraries Framework
Common Language Runtime (CLR)
virtual machine (like Java)
Microsoft operating systems since Win98 free download
10-Nov-11 compare.ppt 18
Java platform components download free
Software Development
Kit (SDK)
compilers
Java JRuby JPython …
web services automation beans, remoting, servers
various open source
Java Server Pages and servlets and proprietary players
Data and XML
Java API’s JRE and JDK
Java Runtime Environement (JRE)
virtual machine
Unix, Linux, Max OS X, Windows free download
10-Nov-11 compare.ppt 19
who implements Java runtimes?
Sun Microsystems
• Java HotSpot Virtual Machine
for Windows, Linux, Unix
Hewlett-Packard
• Java runtime for HP-UX, OpenVMS,
Tru64, Reliant(Tandem) UNIX)
IBM
• Java runtime for MVS, AIX, OS/400, z/OS
Apple Computer
• MacOS Runtime for Java (MRJ)
• J2SE built-in on Mac OS X
• includes JDK (compilers)
BEA Systems
• JRockit (for their web server)
10-Nov-11 compare.ppt 20
jargon checklist
• metadata
• bytecode
• JVM
• JRE • what is an assembly?
• JDK • an .exe or .dll file compiled by a .NET compiler
• J2SE • what is “metadata”?
• the self-describing information inside a .NET assembly or Java
• J2ME .class file
• J2EE • What is CIL? (formerly MSIL)
• Common Intermediate Language (inside a .NET assembly)
• IDE
• What is the CLR?
• GUI • Common Language Runtime that executes CIL code
• what is managed code?
• software that runs in the CLR
• what is native code (or unmanaged code)?
• software than can run on Windows without the CLR
10-Nov-11 compare.ppt 21
3 why did Sun do it?
10-Nov-11 compare.ppt 22
C and C++ perceived common problems
• pointers are dangerous
• memory leaks (failing to free memory correctly)
• function pointers (jumping to the wrong place)
• data pointers (pointing to the wrong place)
• manual garbage collection is a lot of work
• multiple inheritance (C++) can get very complicated
• ambiguities like the ―diamond problem‖ (a.k.a. ―diamond of
death‖)
• not easily portable across platforms, even with re-compile
and discipline
10-Nov-11 compare.ppt 23
a few ways Java improved on C++
• instead of pointers, Java has references
• references are similar to pointers, but with protections (cannot
jump into illegal parts of memory)—avoids segmentation fault
problems
• automatic garbage collection
• memory is reclaimed from the heap automatically—avoids
memory leaks
• single inheritance
• avoiding the deadly diamond of death
• encapsulation
• all code must be in a class—intended to encourage information
hiding
• array bounds checking
• libraries
• many common tasks already coded and available for ―reuse‖ by
means of inheritance
• many interfaces (behaviors) already coded
10-Nov-11 compare.ppt 24
4 why did Microsoft do it?
10-Nov-11 compare.ppt 25
Microsoft’s big headache
• prior to .NET, Microsoft had a big headache
• Microsoft was supporting too many operating systems
• application programming interfaces (API’s) were implemented
as dynamic link libraries (DLL’s) develop using C++
• calling the Windows API was different on every operating
system
• developers first had to find out exactly what kind of system the
program was running on
• and then determine if the API desired was actually installed on the
system
• that doesn’t sound so bad
• after all, there are only a few different kinds of Windows…
…right?
10-Nov-11 compare.ppt 26
party trivia question
• how many different versions of the Windows operating
system existed before Vista, which had their own distinct
mix of API’s?
select the closest answer:
a) 5
b) 15
c) 25
d) 35
10-Nov-11 compare.ppt 27
Windows versions which can run the .NET framework
1. Windows 98 22. Windows XP Professional x64 Edition
2. Windows 98 Second Edition 23. Windows Server 2003, Standard x64
Edition
3. Windows 2000 Professional with SP4
24. Windows Server 2003, Enterprise x64
4. Windows 2000 Server with SP4 Edition
5. Windows 2000 Advanced Server with SP4 25. Windows Server 2003, Datacenter x64
6. Windows 2000 Datacenter Server with SP4 Edition
7. Windows XP Professional with SP2 26. Windows Server 2003 R2, Standard x64
8. Windows XP Home Edition with SP2 Edition
9. Windows XP Media Center Edition 2002 with SP227. Windows Server 2003 R2, Enterprise x64
10. Windows XP Media Center Edition 2004 with SP2 Edition
11. Windows XP Media Center Edition 2005 28. Windows Server 2003 R2, Datacenter x64
Edition
12. Windows XP Tablet PC Edition with SP2
29. Windows Server 2003 with SP1, Enterprise
13. Windows XP Starter Edition Edition for Itanium-based Systems
14. Microsoft Windows Millennium Edition 30. Windows Server 2003 with SP1,
15. Microsoft Windows Server™ 2003 Standard Datacenter Edition for Itanium-based
Edition Systems
16. Windows Server 2003 Enterprise Edition 31. Windows Server 2003 R2, Enterprise
17. Windows Server 2003 Datacenter Edition Edition for Itanium-based Systems
18. Windows Server 2003 Web Edition 32. Windows Server 2003 R2, Datacenter
19. Windows Server 2003 R2, Standard Edition Edition for Itanium-based Systems
20. Windows Server 2003 R2, Enterprise Edition 33. Microsoft Windows Mobile™ for Pocket PC
21. Windows Server 2003 R2, Datacenter Edition 34. Windows Mobile for Smartphone
35. Microsoft Windows CE
• NOTE: does not include Vista
10-Nov-11 compare.ppt 28
Windows versions that can not run the .NET framework v2.0
1. Windows 95
2. Windows NT® Server
3. Windows NT Workstation
4. Windows Server 2003, Enterprise Edition for Itanium-based Systems
5. Windows Server 2003, Datacenter Edition for Itanium-based Systems
10-Nov-11 compare.ppt 29
5 Service Oriented Architecture – the peacemaker?
10-Nov-11 compare.ppt 30
who are the big web server and database marketplace players?
• Sun
• IBM
• BEA
• SAP
• Oracle
• Microsoft
10-Nov-11 compare.ppt 31
world wide web development
• Java servlets • .NET handlers
• Java Server Pages (JSP) • Active Server Pages (ASP.NET)
• Beans • .NET DLL’s and .NET custom controls
• CORBA (binary) • COM (binary)
• XML web services (SOA) • XML Web services (SOA)
10-Nov-11 compare.ppt 32
Service Oriented Architectures (SOA)
• web services
• remotely located programs that use XML to make remote calls
and get the results
• XML traveling over HTTP
• it’s all plain text and goes through firewalls
• standards are emerging
• Jave service end points and Microsoft client endpoints can talk
to each other (and vice versa)
10-Nov-11 compare.ppt 33
what we just covered
1. simple programs
2. overview of platforms
3. why did Sun do it?
4. why did Microsoft do it?
5. Service Oriented Architecture – the peacemaker?
10-Nov-11 compare.ppt 34
the end of this PowerPoint file
Hooray!
10-Nov-11 compare.ppt 35