Post on 25-Dec-2015
Course Objectives
Understand how do Services work. Presentation, protocol and format.
Create and consume a Service in .NET. Creating, deploying and consuming them.
Optimize Services. By using cache, sessions…
After this course, you will be able to:
Services
Course Topics
Introduction. Protocol and formats used in Services.
Services in .NET. Creating, deploying and consuming Services in .NET.
Optimizing Services. By using cache, sessions…
This course is divided into the following sections:
Services
Service Basics
Introduction, protocol and format of services…
Services
Section Topics
Introduction to Services
SOAP Protocol
WSDL Format
UDDI Directory
We are going to walk through the following chapters:
Service Basics
Introduction to Services
A Service is a group of protocols and computer standards, used for exchanging data between applications.
— Wikipedia,
Service Basics
OOP complement
Used in processing and communicating with Services.
Objectives
Productive
Reactive
Capable of managing responsibility
SOA : Services Oriented Architecture
Service Basics
Introduction to Services
Based on 4 principals:
The borders are explicit.
The services are independent of one another.
Contracts are shared, but not objects.
Semantics are dictated by rules.
SOA : Services Oriented Architecture
Service Basics
Introduction to Services
Service Basics
Introduction to Services
Amazon
Internet
A service and clients communicates by messages.
A client sends a request, the server sends back a response.
Advantages:
Interoperability
Simplified access
Accessible data exchange format
Centralized arrangement
Disadvantages:
Poor performance
Ever-changing standards
Advantages and disadvantages of Services
Service Basics
Introduction to Services
Allows the transmission of structured and formatted data in messages between 2 distant objects.
Standard defined by W3C
Based on XML
Current version: 1.2
Service Basics
SOAP Protocol
SOAP ProtocolService Basics
Envelope:
is the root element of SOAP message.
contains no or several attributes.
contains
Header (optional)
Body (mandatory)
Composition of a message
SOAP ProtocolService Basics
Header :
Optional
Used for adding complementary information to the message
Contains arguments: actor, mustUnderstand…
Body :
Contains data of the message
Corresponds to the XML Schemas specified in the service contract.
Composition of a message
SOAP ProtocolService Basics
Example of a SOAP message
<soap:Envelope xmlns:"http://schemas.xmlsoap.org/soap/envelope"/><soap:Header>
</soap:Header><soap:Body>
</soap:Body></soap:Envelope>
WSDL Format
WSDL defines, in an abstract and independent way, a group of operations and messages which can be transmitted to and from a given Service.
— JDNet Developers,
Service Basics
WSDL FormatService Basics
Description language of Services in XML format
Used to draft a Service: describing functionalities
“how”
“where”
Current version: 2.0
Service Description Language
WSDL :A contract
Location
Operation’s description
Type Description
WSDL FormatServices Basics
WSDL FormatService Basics
WSDL skeleton
<definition><type />
<message><operation>
<message /></operation><portType>
<operation/></portType><binding>
<operation/></binding><service>
<port><binding/>
</port></service>
</definition>
UDDI DirectoryWhat is it?
Service Basics
Universal Description, Discovery and Integration
It is a directory of Services.
which is a Service itself.
It contains
information on service providers (contracts, activities…)
description on services(as part of the WSDL contract)
UDDI DirectoryService Basics
1. I am looking for a Service…
2. Tell you how to connect to it.
3. What is the format for messages?
4. Here is my WSDL contract.
5. I send my SOAP requests.
6. Result for the SOAP request.
How does it work?
Stop-and-Think
Do you have any questions?
Service Basics
Services in .NET
Creating, deploying and consuming Services in .NET.
Services
In .NET you can use:Introduction
WCF
WCF RIA Services
WCF Data Services
WCF and SOAIntroduction
Most developers do not have to learn WSDL
Lots of functionality is handled by the runtime
Tools to enable easy creation and consumption of services
WCF supports SOA:
Just because you have exposed an interface over a Web service protocol stack does not mean that you have created part of an SOA
WCF plays the role of distribution mechanism, while SOA comes in at a higher level
However:
PreviewWCF Basics
Section plan:
Service-Oriented Development with WCF
Sending a WCF Message
The ABC of Endpoints
Structure of a Service
A Unified Programming Model
Communicating with Non-WCF Services
A unified development model
WindowsCommunication
Foundation
Many confusing and complicated options
Remoting COMDCOM
COM+MSMQ
WSEASMX
A Unified Programming ModelWCF Basics
Service-Oriented Development with WCFWCF Basics
Over a network protocol
Create a service:
Contact the service to access one part of that functionality Use a service:
Clients and services communicate by passing messages
Not limited to one particular set of protocols
Aimed at clients and services that do not share the same address space
Service-oriented architecture is a bigger concept related to the style of the application and granularity of the services
Service
Where to find the service
Example: http://localhost:8001/MathService
Where to find the service
Example: http://localhost:8001/MathService
AddressAddress
How to communicate with the service
Example: BasicHttpBinding
How to communicate with the service
Example: BasicHttpBinding
BindingBinding
What the service can do for you
Example: [OperationContract]int Add(int num1, int num2);
What the service can do for you
Example: [OperationContract]int Add(int num1, int num2);
ContractContract
The ABC of endpointsWCF Basics
Client ServiceWCF
dispatcherProxy
Message EncodingEncoding
Transportchannel
Transportchannel
ChannelChannelChannelChannel
ChannelChannel
Transportchannel
Transportchannel
EncodingEncodingBindingBinding
ChannelChannelChannelChannel
ChannelChannel EndpointsEndpoints
Sending a WCF messageWCF Basics
Service
.NET Classesand Interface
ServiceHostService Contracts for
Domain Functionalityor Metadata Exchange
Structure of a serviceWCF Basics
Stop-and-think
Do you have any questions ?
WCF Basics
Using a Language-Level Interface as a Service Contract
Defining a service contract
Windows Communication Foundation
Example of a Simple Contract
The ServiceContract Attribute
The OperationContract Attribute
Data and Messages
Defining a data contract
PreviewDefining a service contract
Section plan:
using System;using System.ServiceModel;
namespace ServiceContracts{ [ServiceContract(Namespace="http://myuri.org/Hello") ] public interface IService { [OperationContract] HelloMessage GetHelloMessage(string name); }}
Principal namespace for WCF
Defining a service contract
Attributes control exposure of types and methods
Example of a Simple Contract
Defining a service contract
The ServiceContract attribute:
The ServiceContract attribute
Can be used on interfaces or classes
Is identified by tools and environments that understand WCF
Support services
Are analogous to interfaces on a polymorphic object – caller may not know or care about other contracts
Are only visible to clients if exported on an endpoint
Contains one or more operations
Service contracts:
Defining a service contract
Namespace serves to disambiguate types and operations in service metadata
The ServiceContract attribute
Defaults to http://tempuri.org
Not to be confused with language-level namespace
Defining a service contract
The OperationContract Attribute:
The OperationContract Attribute
Attribute can be used on methods but not other class elements, such as properties or indexers
Identified by tools and environments that understand WCF
Methods are only visible in service contract if marked with OperationContract
Defining a service contract
Data and messages
Parameters and return values must be marshaled between client and server
CLR types are mapped to XML Infoset by serialization
WCF enables you to define custom serialization
Serialized data is packed into the message
Contents and structure of message must be understood by client or service at the other end
Data and message contracts provide control overthese areas
Defining a service contract
Defining a data contract
using System;using System.Runtime.Serialization;
namespace DataContracts{ [DataContract] public class HelloMessage { private string _content;
[DataMember] public string Content { get { return _content; } set { this._content = value;} }}
Defining a service contract
Implementing a service contract
Define a class implementing the service contract
using System;using ServiceContracts;using DataContracts;
namespace ServiceImplementation{ public class HelloService : IService { public HelloMessage GetMessage(string name) { // Write implementation code here } }}
Stop-and-think
Do you have any questions ?
Defining a service contract
DemonstrationDefining a service contract
Service
contracts and
implementation
Hosting and Consuming a WCF Service
Windows Communication Foundation
Separation of Concerns in a WCF Service
Life Cycle of a Self-Hosted WCF Service
Consuming a WCF Service
Configuring a WCF Service Host and a client
Generating artifacts from service metadata
Hosting and Consuming a WCF Service
Preview
WCF Service HostWCF Service Library
Contract
Implementation
Configuration
WCF solution
Host code
Hosting and Consuming a WCF Service
Separation of Concerns in a WCF Service
Life Cycle of a Self-Hosted WCF Service
Hosting and Consuming a WCF Service
Using the namespace System.ServiceModel
Instantiate a Service Host object
System.ServiceModel.ServiceHost
Add a service endpoint with :
Contract
Binding
Address
Open the ServiceHost to start listening
11
22
33
Life Cycle of a Self-Hosted WCF Service
Hosting and Consuming a WCF Service
Prevent the ServiceHost from closing (i.e Console.ReadLine()
Close and dispose of the ServiceHost object
44
55
ServiceHost
Service type Address
Calling a WCF Service
Hosting and Consuming a WCF Service
A channel over which to pass messages
Transport channel at the bottom
The makeup of the channel derives from the binding
A client-side representation of the contract
Referencing the service contracts assembly
Generating artifacts from metadata
A way of creating WCF messages to pass across the channel and a way of retrieving message contents
An address for the WCF service
To call a WCF service, the client needs the following:
ServiceClass
ServiceInterface
ServiceMetadata
Implements
RunningService
ServiceProxy
Implements
ServiceAssembly
ProxyArtifacts
GenerateGenerateGenerateGenerate
GenerateGenerate
ServiceModel Metadata Utility Tool (Svcutil.exe) generates metadataand artifacts
ServiceModel Metadata Utility Tool (Svcutil.exe) generates metadataand artifacts
Hosting and Consuming a WCF Service
Contracts, metadata and artifacts
Consuming a service (1)
Hosting and Consuming a WCF Service
Using the ChannelFactory class
Reference the Service Contracts assembly
Instantiate a typed Channel Factory with the binding and the address of the service
System.ServiceModel.ChannelFactory<T>
T represents the type of the contract
Call the CreateChannel() method to contact the service and create a proxy
Start calling the methods…
11
22
33
44
DemonstrationHosting and Consuming a WCF Service
« First WCF
Demo »
File-based configuration
Hosting and Consuming a WCF Service
File-based configuration
You can use app.config, web.config, and machine.config files
You can change the WCF configuration without recompiling the assembly
Programmatic configuration
Provides greater control of your WCF configuration
Takes precedence over file-based configuration
Identifying WCF Entries in Configuration Files
Hosting and Consuming a WCF Service
Host configuration file
<system.serviceModel> <services> <service name=”ServiceImplementation.HelloService"> <endpoint address="http://localhost:1664/HelloService" binding="basicHttpBinding" contract="ServiceContract.IService"/> </service> </services></system.serviceModel>
<system.serviceModel> <client> <endpoint name="tcpEndpoint" address="http://localhost:1664/HelloService" binding="basicHttpBinding" contract="ServiceContract.IService"/> </client></system.serviceModel>
Client configuration file
DemonstrationHosting and Consuming a WCF Service
« Configuration
»
WCF Service
MEX endpoint
WCF types
Artifacts
Hosting and Consuming a WCF Service
Obtaining Service Information
Obtain information from service metadata and generate artifacts
Obtain information and artifacts manually from service provider
Consuming a service (2)
Hosting and Consuming a WCF Service
Using generated artifacts – Mex (Metadata Exchange)
Add a reference to the service (“Add Service Reference”)
The tool Svcutil.exe generates code from the metadata of the service:
Proxy classes and interface
Instantiate a proxy service class object
Start calling the methods…
11
22
33
DemonstrationHosting and Consuming a WCF Service
« Mex »
Solutions to host a WCF Service
Windows Communication Foundation
Hosting a service in a self-managed Application
Hosting a service in a Windows Service
Hosting a service in IIS
Hosting a service in WAS
Solutions to host a WCF Service
Preview
Hosting a service
Solutions to host a WCF Service
Host environment
Typical functionality:
• Reads and understands WCF configuration settings
• Creates endpoints and listens for requests from remote clients
• Routes requests to an appropriate service instance
• Creates and destroys service instances
Additional functionality:
• Isolate different service instances from each other
• Serialize and re-activate unused service instances
• Manage pre-created pools of service instances
Service Hosting Options
Solutions to host a WCF Service
Self-hosted managed application
IIS
WAS
IIS and WAS offer the following improved hosting features:
Message-based activation
Process recycling
Idle shutdown
Process health monitoring
Windows Forms application
Windows Console application
Windows service
WPF application
Solutions to host a WCF Service
Hosting a WCF Service in a Self-Hosted Managed Application
Implementing a Self-Hosted Service
Solutions to host a WCF Service
Manually activated by starting process
Need to write your own hosting code
WCF configuration in the app.config file
Expose your WCF service over any protocol
Self-hosted service application
WCF configurationService host code
Hosting in a Windows Service
Solutions to host a WCF Service
Easily auto-started on startup
Manage process life cycle in the managementconsole snap-in
Subclass ServiceBase and override OnStart and OnStop
protected override void OnStart(string[] args){ //Instantiate the ServiceHost...}
protected override void OnStop(){ // Close the ServiceHost...}
DemonstrationSolutions to host a WCF Service
« Windows
Service
Deployment »
Implementing an IIS-Hosted Service
Solutions to host a WCF Service
Instances activated when messages arrive
No hosting code required from service developer
WCF configuration in web.config file
Limited to HTTP protocol
Need service file (.svc) containing ServiceHost directive to link IIS to service class
In its simplest form, you can store the service classes in the
App_Code sub directory
<%@ServiceHost Service="ServiceImplementation.HelloService"%>
DemonstrationSolutions to host a WCF Service
« IIS
Deployment »
Implementing a WAS-Hosted Service
Solutions to host a WCF Service
No hosting code required from service developer
WCF configuration in web.config file
Not limited to the HTTP protocol
Need service file (.svc) containing ServiceHost directive to link IIS to service class
<%@ServiceHost Service="ServiceImplementation.HelloService"%>
Configuring WAS
Solutions to host a WCF Service
Enable “WCF Non-Http Activation Components” Windows components
Bind desired Web site (usually default) to a non-HTTP port to support non-HTTP-based activation
appcmd set site "Default Web Site"-+bindings.[protocol='net.tcp',bindingInformation='9000:*']
appcmd set app "Default Web Site/BankService“ /enabledProtocols:http,net.tcp,net.pipe
Ultimately the service must leave the development environment
Deployment mechanism and process depends on type of service host
Preparing Services for Deployment
Solutions to host a WCF Service
Compile code
Install correct runtime
Check endpoint addresses Disable debugging
Deploying IIS-Hosted Services
Solutions to host a WCF Service
Deploying WAS-Hosted Services
Solutions to host a WCF Service
+Perform WAS setup:
1. Install components
2. Configure non-HTTP activation
Compile code
Install correct runtime
Check endpoint addresses
Disable debugging
Create a Windows Installer (MSI) for the classes
Register your Windows Service at installation time by using ServiceProcessInstaller and ServiceInstaller
Deploying Self-Hosted Services
Solutions to host a WCF Service
[RunInstaller(true)]public class ProjectInstaller : Installer{ private ServiceProcessInstaller process; private ServiceInstaller service;
public ProjectInstaller() { process = new ServiceProcessInstaller(); process.Account = ServiceAccount.LocalSystem; service = new ServiceInstaller(); service.ServiceName = "HelloService"; Installers.Add(process); Installers.Add(service); }}
Stop-and-Think
Do you have any questions?
Services
For more…
CoursesBooks
Websites
http://www.dotnetguru.org
ASP.NET 2.0 Basics
Security and Customization of Web Applications
If you want to go into the topic more deeply,
http://www.asp.net
www.fnac.com
Services
http://stephaneey.developpez.com/tutoriel/dotnet/webservice/
Congratulations
You have successfully completed
Module 4
Services
End
Adopt Services for your distributed applications!
You have finished the modules ASP.NET 2.0 and Services!
Services