ions and Diif Between J2EE and NET

8/3/2019 ions and Diif Between J2EE and NET

1/98

Comparing J2EE with .NET

- ACCU 2002 -

Slides (mostly ) byMichael Stal, Senior Principal EngineerSIEMENS AG, Dept. CT SE 2E-Mail: mailto:[email protected]: http://www.stal.de

Markus Voelter, CTO, MATHEMA [email protected]

http://www.voelter.de
mailto:[email protected]://www.stal.de/mailto:[email protected]://www.voelter.de/http://www.voelter.de/mailto:[email protected]://www.stal.de/mailto:[email protected]


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Markus Voelter/Michael Stal

Comparing J2EE with .NETFolie 2

Goal

This is intended to be an objectivecomparisons of the two platforms

It will contain criteria to base a decisionwhich platform to use

Interoperability issues


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Agenda

Motivation

Comparison Visions: Sun ONE and .NET

Layer-by-Layer comparison of the infrastructures

Summary

Literature


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Web Frameworks

Workflow Engine

Web-based and -related Protocols (HTTP, SMTP, ...)

Service Description, Discovery, Integration (UDDI)

Service Description (WSDL)

Service Context (Who, Where, When, Why, ....)

Virtual Machine

Micro/Macro Services

IntegrationLayer

Legacy

Backend Server

MainframeFrontend

Layer

(Web Server)

Web Service User/Provider

Core Services (Calendar, Preferences, Transactions, ...)

Core elements of Web Frameworks

Clients


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.NET The MicrosoftWay of Life

.NET DevicesTabletPC, PocketPC, ....

.NET Servers

SQL Server, Biztalk, Commerce, Exchange, Mobile Information,

Host Integration, Application Center

.NET Foundation Services (Hailstorm)

Passport, Calendar, Directory & Search, Notification & Messaging,

Personalization, Web-Store/XML, Dynamic Delivery of Software and Services

Common Language Runtime

(Memory Management, Common Type System, Lifecycle Monitor)

.NET Framework & Tools

Base Classes

(ADO.NET, XML, Threading, IO, ....)

ASP.NET(Web Services, Web Forms,

ASP.NET Application

Services)

Windows Forms(Controls, Drawing,

Windows

Application Services)


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Sun ONE (Open NetEnvironment)

Service Interface

ServiceContainer

(J2EE, EJB, JSP,J2SE, J2ME,

MIDP, Java Card)

ProcessManagement

ServiceIntegration

(SQL, JDBC, XML,XSLT, XP, JMS,

RMI, J2EE Connectors,...)

Service PlatformSmart Management

(SNMP, CIM, WBEM, JMX)

Smart Delivery(XML, HTML, XHTML,

WML, VoiceXML,XSLT, HTTP, SSL,XP, SOAP, WSDL,UDDI, ebXML, ...)

Web Services

Smart Process(ebXML, XAML)

Smart Policy

(LDAP, Kerberos, PKI,OASIS Security))

Service Creation and Assembly(JB, JSP, EJB)


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Layer-By-Layer Comparison


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Hello World Example

In C# and Java:using System;

namespace MyNameSpace {public class MyClass {

public static void Main(String [] args) {Console.WriteLine(Hello, C#!);}

}}

package MyPackage;

public class MyClass {public static void main(String [] args) {

System.out.println(Hello, Java!);}

}


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Layers

Runtime System

Object model

Base classes

- Reflection, Enterprise

- Component model- Database access- XML- Server Pages- Remoting- Web Services- More Enterprise APIs


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The Runtime System


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.NET Runtime

It is called the Common Language Runtime (CLR) It is intended for any language compiled to the MSIL

Provides integration for several languages

Provides support for non-OO languages (e.g. tailrecursion)

C#

VB.NET

C++

Perl

Compiler

MSIL +

Metadata

Loader/

Verifier JIT

ManagedCode

Execution

GarbageCollection,Security,

Multithreading,...


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Java Virtual Machine

The JVM is intended for Java and interprets Java Byte Code. Other languages can be compiled to Java bytecode, however

(e.g. Ada)

Just-in-Time compilers exist for different environments andOSs

Java

C

ompiler

CLASS-Files

Classloader/Verifier JIT

NativeCode

Hotspot

InterpreterGarbage

Collection,Security ManagerCall-in+Call-out,Multithreading,

...


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Commonalities andDifferences

Commonalities: Basic concepts are similar

Differences:

Java is intended for interpretation (e.g. type-dependent primitives i_add, ...)

Java allows for custom class loaders and securitymanagers

.NET CLR provides a command set that alsosupports functional languages


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The Object Model


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Object Model (.NET)

In .NET, everything is an object

Types

Value Types Reference Types

System ValueTypes

User ValueTypes

Enumerations

InterfacesPointers

Self-describingTypes

ArraysClasses

Delegates Boxed Values

User-Defined


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System.Object

The mother of all .NET classes

public class Object {public virtual int GetHashCode();public virtual bool Equals();public virtual String ToString();public static bool Equals(object a, object b);public static bool ReferenceEquals(object a,

object b);

public Type GetType();protected object MemberWiseClone();protected virtual Finalize();

}


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Object Model (.NET)

.NET distinguishes between values typesand reference types: value types reside on the stack

reference types reside on the heap

In C#, there is no difference betweenprimitive types and classes Automatic boxing/unboxing provides transparency

Special strongly-typed functionreferences called delegates

and events)


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Object Model (Java)

Java has primitive types and classes. No automatic boxing/unboxing

Types

Primitive Types Reference Types

InterfacesArrays

Classes


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java.lang.Object

The Mother of all Java classes

public class Object {public Object();public boolean equals(Object obj);public final Class getClass();public int hashCode();public final void notify();public final void notifyAll();public String toString();public final void wait() throws InterruptedException;public final void wait(long timeout) throws

InterruptedException;public final void wait(long timeout, int nanos)

throws InterruptedException;protected Object clone() throws CloneNotSupportedException;protected void finalize() throws Throwable;}


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Object Model (Java)

Primitive types cannot be transparentlyused as an object. Special Holder classesare necessary.

There are no special function references.

Java uses Observer Pattern withcallback interfaces and inner classes

Integer i_ref = new Integer(7);List l = ...l.add( i_ref );


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.NET-Types that are notavailable in Java

Delegates & Events:

class MyClass {...public void somebodyTurnedOnTheLight( int which ) {

...}}

class AnotherClass {...public delegate void LightTurnedOn(int which);

public event LightTurnedOn OnLightTurnedOn;...OnLightTurnedOn+= new

LightTurnedOn(MyClass.somebodyTurnedOnTheLight);}


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.NET-Types that are notavailable in Java contd

Enumerations (value type):

Jagged and unjagged Arrays:

Structs (value types):

Structs are implicitly sealed they do not support inheritancepublic struct Name {

public String First;public String Last;

}

int [2][] a; a[0] = new int[]{1}; a[1] = new int[]{1,2};int [,] a = new int[2,2];

enum Color : byte { RED = 1, BLUE = 2, GREEN = 3 };


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Commonalities: Interfaces are completely abstract classes Support single inheritance for classes (implementation

inheritance) and multiple interface inheritance Default-Initialization of Variables Namespace-Concept (Java-Package and .NET-Namespace) Similar visibility attributes (public, private, ...) Future: Generic types in .NET and Java (Generics) Class Constructors (static initializer in Java)

Differences In .NET there is no difference between primitive types and

classes. Multiple languages support in .NET In Java all methods are implicitly virtual. In .NET this has to

be made explicit virtual, override, new). Java maps packages to directories. .NET doesnt.


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Metainformation

Java and .NET provide a reflection API to load and instantiate classes

and inspect classes (introspection).

In addition, .NET allows to annotatemany aspects of a system (classes,members, operations) with so-called

Attributes


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.NET Examples

Using an Atttribute

There are several predefined attributes(WebService, WebMethod, ...)

Defining an Attribute

[AuthorIs(Michael)]class MyClass { ... }

[AttributeUsage(AttributeTargets.All)]public class AuthorIsAttribute : Attribute {private string m_Name;public AuthorIsAttribute(string name) { m_Name = name;}

}


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.NET Examples contd

Accessing and using Type informationusing System;using System.Reflection;

namespace ComponentClient {

class Client {static void Main(string[] args) {Assembly a = Assembly.LoadFrom("Component.dll");Type [] allTypes = a.GetTypes();Type t = allTypes[0];object o = Activator.CreateInstance(t);

MethodInfo mi = t.GetMethod("algorithm");double d = (double) mi.Invoke(o, new object[]{21.0});}

}}


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Java Example

Accessing and using Type information: Note that packages are not the same as

assemblies!!

import java.lang.reflect.*;

try {Class c = Class.forName(MyPrintComponent);Object o = c.newInstance();Method m = c.getMethod(print, new Class[]{ String.class });m.invoke(o, new Object[]{Hallo, Java!});

}catch (Exception e) {// handle it here

}

C li i d


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Commonalities: Very similar APIs

Differences:

.NET allows additional, user-defined metainformation with attributes

Java Reflection is sometimes a bit more clumsy(because of primitive types and classes)

.NET allows to actually create new artifacts atruntime and instantiate them or store them inassemblies.


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Statements

Both platforms support basically thesame statements

Differences:

switch-Statement allows Strings, but nofallthrough:

string name = address.name;switch (name) {

case Maier: Console.WriteLine(Nice to meet you, Hans!);break;

case Mueller,case Huber: Console.WriteLine(You owe me some money!);

break;default: Console.WriteLine(I dont know you);

break;}


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Statements (contd)

Differences: Iterators in .NET:

Note that these are still no internal iterators as inSmalltalk, for example!

foreach (Elem i in MyContainer) { Console.WriteLine(i); }...

class MyContainer : IEnumerable, IEnumerator {public IEnumerator GetEnumerator() {

return (IEnumerator)this;}public void Reset() { ... }public bool MoveNext() { ... }

public object Current { get { ... } }}


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Statements (contd)

Differences: Iterators in Java:

for (Iterator i = MyContainer.iterator(); i.hasNext();)doSomething(i.next());

...class MyContainer implements Iterator {

public boolean hasNext() {}public Object next() {...}public void remove() {...}public Iterator iterator() { return this; }

}


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Statements (contd)

Differences: Properties in .NET, where Java uses Coding

conventions

Class MyClass { ...

public double x {set { if (x < 0)

throw new ArgumentException (< 0);m_x = value;

}

get { return m_x; }} ...

// User:MyClass m = new MyClass(); m.x = 22;


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Statements (contd)

Differences: .NET supports Indexers, Java does not.

Indexers also work with non-integer keys, such asstrings

object[17] = 22;

// In class:Int [] m_a;public double this[int pos] {

get { return m_a[pos]; }set { m_a[pos] = value; }

}


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Statements (contd)

Differences: .NET supports operator overloading!

public static Point operator+(Point op1, Point op2) {

return new Point(op1.x+op2.x,op1.y+op2.y);}

...

Point p = new Point(1,2) + new Point(2,3);


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Statements (contd)

Differences: .NET allows pass-by-reference of method

arguments

class Test {

public void Print(int i) { Console.WriteLine(i); }public void Inc(ref int i) { i++; }public int SetInitial(out int i) { i = 42; }...

}

Test t = ...; int i;t.SetInitial(out i);t.Inc(ref i);t.Print();


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Statements (contd)

Exceptions in Java Exceptions have to be declared in the throws-clause

Exceptions in .NET Exceptions are not declared

public int insert(int i) throws OverLimitException;{ }

// only way to tell you about// OverLimitException thrown belowpublic int insert(int i) { }


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Important Base Classes

.NET Java

GUI Windows.Forms

Web.Forms

SWING, AWT

Kommunikation System.Net:Connection,HttpWebRequest,...

Java.net: Sockets, URL,...

Container System.Collections:

ArrayList, BitArray,Maps, Queue, List,Stack

java.util: Lists, Maps,

Sets, Trees, Vectors

No big conceptual differences here.


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Multithreading


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Multithreading in .NET

.NET uses delegates for multithreading The ThreadStart in the example below

There are monitors for synchronization

The lock in the example belowclass GlobalData {

int m_Value;public int Value { set { lock(this) { m_Value = value; } } }

}class Worker {

GlobalData m_Global;public Worker(GlobalData global) {m_Global = global; }public void loop() { m_global.Value = 42; Thread.Sleep(100); }

}// somewhere else:GlobalData g = new GlobalData();

Thread t = new Thread(new ThreadStart(new Worker().loop));t.Start(); t.Join(); 1


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Multithreading in Java

In Java there is also a class Thread

For synchronization there is thesynchronizedkeyword

class GlobalData {int m_Value;public synchronized int setValue { return m_Value; }

}class Worker implements Runnable {

GlobalData m_Global;public Worker(GlobalData global) { m_Global = global; }public void run() { m_Global.setValue(42); Thread.sleep(100); }

}// somewhere else:GlobalData g = new GlobalData();

Thread t = new Thread(new Worker());t.start(); t.join(); 1

Commonalities and


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Commonalities: Threading is very similar!

Both use some forms of monitor forsynchronization

Differences: In Java, synchronization is better integrated into

the Java language

Java provides better synchronization and threadcommunication (wait, notify, ...).


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Deployment


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Assemblies in .NET

Assembly=Set of Types

Manifest

Module 1

Resources

Type 1IL-Code

Type 2IL-Code

Type 3IL-Code

name

version

Sharedname

Hash

Files

ReferencedAssemblies

Types

Security

CustomAttributes ProductInformation

Metadata


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Assemblies in .NET

Private Assemblies are typically onlyuseful by the owning application

Shared Assemblies are stored in a

common cache and can be used byseveral applications. They are signed by a key

They are versioned!!

Runtime uses Application Domains as anabstraction for (potentially remote)processes.


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Java JAR files

.jar files are similar to .NETs assemblies They can be shared or private

They can be signed

They contain types

resources

optionally, metadata in manifest files.

There is no versioning!

Commonalities and


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Commonalities: Assemblies and JAR files provide deployment

components

Differences: Much better versioning support in .NET (side-by-

side execution)


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Component Models

Server-Side Components in


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Server-Side Components in.NET

Now Componentis used like in EJB/COM+

To use container-provided services like

synchronisation or transactions COM+services can be used

COM+-Interop provides these features.


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Java Component Models

Client Components and ServerComponents

JavaBeans are Client Components

normal Java classes following some conventions optionally providing metainformation (BeanInfo

class)

public class MyJavaBean {private int color;

public void setColor(int v) { color = v; }public int getColor() { return color; }// a lot of more ...

}

// BeanInfo class not shown here!


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Server Components in Java

Enterprise JavaBeans (EJBs) alwaysreside in a Container that providestechnical aspects (sep. of concerns)

Client

3) Use bean

Naming

Service

1) lookup home

JNDI

4) remove

Application Server (Container)

Remote Bean

Interface

Remote Bean

Home Interface

2) find bean

2) create bean

BeanInstance

EnterpriseBean

EJBContext

4

ejbCreateejb...

DeploymentDescriptor

EJBJar

bean-methods

EJBHome

EJBObject

new

EJB Run-time

Server Components in Java


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Server Components in Javacontd

4 Types of Beans Stateless Session-Beans (Service Components)

Stateful Session Beans (Session Components)

Entity-Beans (Entity Components)

Message-Driven Beans (asynch. ServiceComponents)

A bean is (theoretically) portable acrosscontainers (Application Servers) fromdifferent vendors.

Commonalities and


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Commonalities: Server Components are available (Assemblies +

COM+, EJB).

Interop with legacy components in .NET using

COM+, in Java using CORBA)

Differences: EJB are a more mature and proven model

Special APIs to connect to legacy systems (JavaConnector API)


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Database Access in .NET

In .NET there is ADO.NET connectionless

Data Source

DataSetCommandCommand

Connection

DataReader

DataSet

Client

Managed Provider

i i l


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.NET-Beispiel

using System;using System.Data;using System.Data.SqlClient;

string myConnection =

server=myserver;uid=sa;pwd=;database=StockTickerDB;string myCommand = SELECT * from StockTable;SqlDataSetCommand datasetCommand = new

SqlDataSetCommand(myCommand, myConnection);DataSet myDataSet = new DataSet();datasetCommand.FillDataSet(myDataSet, StockTable);

DataTable myTable =ds.Tables[StockTable];foreach (DataRow row in myTable.Rows) {

Console.WriteLine(Value of {0} is {1},row[LongName], row[Value]);

}

O


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ADO.NET

ADO.NET is XML based (XML Infoset) DataSet dynamically builds an XML schema inside

to store the data Relational data and XML data can be handled in a

similar way!!ADO.NET works offline once the data is

fetched Updating is partly automatic using DataSets

Currently there are two ManagedProviders: SQL Server ADO

D b A i J


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Database Access in Java

Java provides JDBC to access relationaldata

ODBCDB

ODBC Driver

JDBC/

ODBC Bridge

Driver ManagerConnection

Statement

PreparedStatement

Callable

Statement

Resultset

Application

J E l


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Java Example

import java.sql.*;// without error handling:Class.forName(sun.jdbc.odbc.JdbcOdbcDriver);Connection

con=DriverManager.getConnection(jdbc:odbc:stocks,,);

Statement stmt = con.CreateStatement();ResultSet rs = stmt.executeQuery(SELECT * from stocks);while (rs.next()) {

System.out.println(rs.getString(COMPANYNAME));}rs.close();

stmt.close();con.close();

D t b A i J


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Database Access in Java

There are several other APIs: Embedded SQL in the form of SQLJ (uses JDBC

internally)

Proprietary ODBMS APIs

Standardized JDO API to provide (more or lesstransparent) persistence for Java Objects

XML is handled differently!

Java Connector API provides access to other

connection oriented legacy systems (such as SAPR3)

Commonalities and


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Commonalities: Decoupling of the concrete data model and the

user (using DataSets and ResultSets)

Differences: ADO.NET uses XML extensively, JDBC has a more

relational flavor

JDBC is connection oriented, ADO.NET alwaysworks non-connected, or offline

.NET DataSets are a kind of In-Memory-Database-Cache.

XML


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XML

XML d NET


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XML and .NET

.NET is very XML-centric Web Services (SOAP)

Configuration Files

Result sets of a database access (ADO.NET)

XML processing itself

Note that formally, many .NET features

are based on the XML infoset (XMLsemantics) and do not necessarilyrequire megabytes of text data!!

XML d NET td


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XML and .NET contd

The System.Xml Namespace provides awhole lot of classes DOM processing using XmlNode & Sons

XPath and XslTransform

XmlTextReader und XmlTextWriter similar toSAX in that they are both stream-based, but .NETuses a Pull-Model

XML d J


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XML und Java

There are several standards and tools available DOM, SAX Xerces/Xalan, JDOM JAX{M,B,R,RPC} Castor

However, Javas libraries have not been designedwith XML as a basis (Javas too old ) JAXP (Java API for XML Parsing) supports DOM

and SAX.

Currently under development JAXM (Java API for XML Messaging) JAXB (Java API for XML Data Binding) JAXR (Java API for XML Registries) JAX/RPC (Java API for XML based RPC)

R ti


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Remoting

Somebody knows anice picture here?

R ti i NET


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Remoting in .NET

Application Domain B

Client

FormattersChannels

Envoy Sinks

Real Proxy

Transparent Proxy

Servant

FormattersChannels

Server Context Sinks

Object Context Sinks

Network

Application Domain A

R ti i NET ( td)


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Remoting in .NET (contd)

.NET Remoting provides pluggabletransports and formatters currently TCP and HTTP transport and binary and SOAP formatters

Contexts are automatically propagated(very neat feature!!)

Only very simple lifecycle managementoptions for servants (compared to EJB or

CORBA) Singleton (one object for all calls) SingleCall (new instance for each call) Client-Activated based on leases

Remoting in NET (contd)


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Remoting in .NET (contd)

Objects can be marshalled by value(Serializable)

Asynchronous invocations are easilypossible without touching the servant

Remoting in Java


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Stub/Skeleton-Layer

Remoting in Java

Several possibilities: RMI/CORBA RMI can use JRMP or IIOP as a transport protocol

Not pluggable changes in the code are necessary

Client Server

Stub Skeleton

Remote Reference Manager

Transport Layer

Commonalities and


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Commonalities: Relatively easy to use

Unterschiede:

.NET Remoting can be extended more flexibly Java provides Interop with CORBA

Asynchronous invocations are not easily possiblewith Java

Web


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Web

ASP.NET


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(Server-Side Scripting)

ASP.NET Architecture:

IIS 5Web

Server

Client

(1) get a.apx (2) process

.NETEngine

.NETAssembly

OtherAssemblies

Database

(3) result(4) HTTP file

ASP NET Example


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ASP.NET Example

A simple loginscreen:

ASP NET Example (contd)


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ASP.NET Example (cont d)

Please specify your name andpassword

Login

Password

ASP NET Example (contd)


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ASP.NET Example (cont d)// lot of details omittednamespace LoginPage {

public class WebForm1 : System.Web.UI.Page {protected TextBox PasswordText, LoginText;protected Button EnterButton;protected Label MessageLabel;private void InitializeComponent() {

this.EnterButton.Click +=new System.EventHandler(this.EnterButton_Click);this.Load += new System.EventHandler(this.Page_Load);

}private void EnterButton_Click(object sender, System.EventArgs e) {

if (!(LoginText.Text.Equals("aladdin") &&PasswordText.Text.Equals("sesam"))) {

MessageLabel.Text = " Wrong name or password!";

}else {Session["user"] = "aladdin";Response.Redirect("UserArea.aspx");

}}

}}

Java Server Pages and


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gServlets

Java also allows for server-side scripting JSPs are based on Servlets

Web

ServerClient

(1) get a.jsp (2) process

JVM

JSP

OtherComponents

Database

(4) result

(5) HTTP file

Servlet

(3) gen. Servlet ServletImpl.

Java Example


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Java Example

Java Example


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Java Example

Bean und JSP-Seite:

// Datei MyPerson.javapackage MyPackage;import java.lang.*;

public class MyPerson {public String getFirstName() { return "Michael"; }public String getLastName() { return "Stal"; }

}// Datei MyTest.jsp: Your name is:

Commonalities and


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Differences

Commonalities: Pages are precompiled to accelerate access Similar syntax and concepts ASP.NET provides GUI components using

Webcontrols, Java provides Taglibs. Differences:

All .NET languages can be used for ASP.NETscripting

Servlets/JSP are available for a wide range ofwebservers

Many open source implementations, frameworksand tools for Java

Web Services in NET


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Web Services in .NET

.NET provides a very comfortable andwell-integrated way to build them:

namespace WebService1 {public class Service1 : System.Web.Services.WebService {

// lot of stuff omitted[WebMethod]public double DM_to_Euro(double value) {

return value / 1.95583;}[WebMethod]

public double Euro_to_DM(double value) {return value * 1.95583;

}}

}

Web Services in NET (forts )


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Web Services in .NET (forts.)

Using it is also simple Some steps have been ommitted

Webservices are just a special way ofremoting

BUT: Microsoft does not provide ebXML compliance Currently they can only be used with MS server

localhost.Service1 s1 = new localhost.Service1();double result = s1.Euro_to_DM(200);

Web Services in Java


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Web Services in Java

Sun ONE will provide a Web Service API forJava, completely ebXML compliant

Currently there are many proprietary solutions Some specific SOAP toolkits:

- Apache SOAP

- IBM Web Services Toolkit- GLUE

Some integrated with the major application servers- Silverstream- IONA - Weblogic- ...

Sun works at standard APIs JAXM

Commonalities and


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Markus Voelter/Michael Stal Comparing J2EE with .NETFolie 82

Differences

Commonalities: Both.NET and Java try to be standards-compliant

(SOAP, WSDL, UDDI).

Handling very similar: WSDLbased generators that

create proxies Differences:

For Java there are different solutions, whereas.NET provides only one, natively

Currently, standards are interpreted differently, soInterop Java-.NET is only limited. But this willhopefully change!!

More Enterprise APIs


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More Enterprise APIs

Enterprise APIs


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Enterprise APIs

Naming: JNDI in Java (as an interface to CORBANaming,

LDAP, ...)

Active Directory in .NET (Windows-specific)

Message-orientierte Middleware: JMS in Java

JAXM is on the horizon (XML based messaging)

.NET can use MSMQ, and remoting can be usedasynchronously

Legacy-Integration


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Legacy-Integration

In .NET using the Microsoft HostIntegration Server.

In Java using the Connector API

Comparison: Java provides a muchsimpler way. Connectors can beimplemented relatively straight forward.

Interoperability


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Interoperability

Java provides access to C/C++ usingJNI (Java Native Interface). Relativelycomplex call-in, call-out.

.NET provides PInvoke:

class PInvokeTest {

[DllImport("user32.dll")]static extern int MessageBoxA(int hWnd, string m, string c, int t);static void Main(string[] args) {

MessageBoxA(0, "Hello DLL", "My Window", 0);}}

Interoperability contd


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Interoperability cont d

In .NET there is a way to interop withCOM+ and COM+ Services.

Java provides CORBA interop

JMS provides integration with MoMs In .NET, the interop between .NET

languages is almost perfect and easy Use the same assemblies, class libraries

Languages had to be adapted a little bit (e.g.Managed C++ does not provide multipleinheritance)

Mobile and Embedded


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Mobile and Embedded

Profiles and devices


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Profiles and devices

There are the following variants of Java J2SE (Java 2 Platform Standard Edition)

J2EE (Java 2 Platform Enterprise Edition)

J2ME (Java 2 Platform Micro Edition)

- Configurations,

- and Profiles

JavaCard

Profiles and devices contd


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Profiles and devices cont d

.NET Universe .NET: Framework for Standard und Enterprise .NET Compact Framework for Windows CE (and other

embedded OS)

- Design Goals:

> Resource saving> Adaptability regarding device properties> Compatibility with the standard IDEs> Easy integration> Seamless connectivity

- No ASP.NET, Reflection.Emit, Optimized JIT- Depending on machine stack- Simplified versioning and security, but

similar formats

Profiles and devices contd


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Profiles and devices cont d

.NET Mobile Web SDK Abstraction for the developer

Several markup languages (WML, HTML, ...)

Configurable and extendible

ASP.NET can be used

Emulators for devices are available for testing anddebugging purposes

Extends ASP.NET with special controls

Selecting one of the two


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Selecting one of the two

.NET and/or Java ?


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.NET and/or Java ?

.NET is a product, Java and J2EE is aspecification

Both adress the web (among other things)

For real big systems J2EE is better suited

The rule-of-thumb Java is platform-independent,.NET is language independentmust be considered carefully:

ECMA works on the standardization of C# and parts of .NET Other languages can be compiled to the JVM

.NET and/or Java ?


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.NET and/or Java ?

.NET language independence is not for free andnot completely transparent

In a real project you might want to use onlyonelanguage But sometimes...

#pragma onceusing namespace System; // .NET mit C++namespace CPPBase {

public __gc class CPPBaseClass {public: virtual System::String __gc* Echo(System::String __gc *s);};}System::String __gc * CPPBase::CPPBaseClass::Echo(System::String __gc *s){ return s; }

.NET and/or Java ?


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.NET and/or Java ?

Windows Applications are probably better donewith .NET than Java (maybe IBMs SWT changesthis ?)

Java should be used when platform (or vendor-) independence is necessary

Java is more mature

There will also be Java for .NET (Rational) But syntax is not the issue!

Both can be used for web services - .NET is

nicer, J2EE is more scalable

Analysts proclaim a fifty/fifty situation for Javaand .NET

Management Summary - 1


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Management Summary 1

.NET JavaController/Owner Microsoft Sun + JCP-Partner

Status Product Line Specification and manyimplementations

Languages C#, C++, Eiffel#, VB, .... Java + possibly others

Communicationmiddleware (RPC,Messaging, Web)

.NET Remoting, MSMQ,Web Services (no ebXML)

RMI/CORBA, JMS, WebServices (standardcompliant)

Server Components COM+ Enterprise JavaBeans

XML-Support Consistent Currently not yetcompletely integrated

Server Pages ASP.NET JSP/Servlets

Management Summary - 2


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Management Summary 2

.NET JavaDatabase access ADO.NET (ADO) JDBC / SQLJ and others

Base libraries Many many classes onSystem.*

Many many classes onjava.*

GUI-Libs Windows.FormsWeb.Forms

Swing/AWT

Runtime .NET CLR Java JVM

Interop (call-in/call-out) PInvoke JNI

InteropMiddleware COM/COM+ (COMInterop)

CORBA, JMS

Legacy Integration Host Integration Server JCA

The End


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The End

Thank you very much!!

Documents

ions and Diif Between J2EE and NET