ColdFusion Internals

transcript

ColdFusion InternalsPaul Nibin K J

Introduction

Client

Web Server

Agenda

Life of a CFM request

Classloading in ColdFusion

How does RESTful web service work?

Life of a request

Life of request in ColdFusion

Template Classloader

In filter chain

1. Request Validation

• Validates the request.

2. PathResolution

• Resolves absolute CFM Path

3.Application Resolution

• Locates Applicati-on.

• Creates Applicati-on scope.

• Invokes life cycle method

4. Parse

• Parse the CFM file .

• Generate AST using the grammar.

5.Bytecode Generation • Translat

e the AST to java byte code

You are part of request validation too.

You can configure the following validations through settings.

Request Size Limits

Request Limits

2. Path Resolution

/employee/addEmployee.cfm

C:\inetpub\wwwroot\employee\addEmployee.cfm

http://localhost/employee/addEmployee.cfm

Absolute

Virtual Path

Request URL

Connector

You can cache the web server path using an admin setting.

3. Application Resolution

Finds the Application.cfc

Creates Application Scope

Invokes Life cycle methods

OnApplicationStart()

OnRequestStart()

OnError()

Finds the Application.cfc

Creates Application Scope

Invokes Life cycle methods

OnApplicationStart()

OnRequestStart()

OnError()

Check for the

Application.cfc in

current directory.

Application.cf

Found Application

Check for the

Application.cfc in

parent directory.

Setting to specify till what level ColdFusion should search for Application.cfc

Unnamed applications

axis1Test

Application.cfc

</cfcomponent>

basic.cfc

axis2Test

Application.cfc

</cfcomponent>

basic.cfc

http://localhost/axis1Test/basic.cfc?wsdl

http://localhost/axis2Test/basic.cfc?wsdl

ColdFusion disables the creation of un named applications using an

admin setting.

4. Parsing

function hello() {

writeOutput("hello");

hello();

</cfscript>Template

Reader

Abstract Syntax Tree (AST)

4. Parsing

function hello() {

writeOutput("hello");

hello();

</cfscript>Template

Reader

Abstract Syntax Tree (AST)

Template Reader

Reads the CFM and creates a stream.

Encoding?

Automatic encoding identification

encoding

(icu4j)

Is guess

probability

Is BOM

present?

Use system

encoding

<cfprocessingdirective

Save the file with

-Dfile.encoding=“”

5. Byte code generation

Byte Code

Engineering Library

(BCEL)

Byte Code

<cfusion_Root>\wwwroot\WEB-

INF\cfclasses

Template Classloader

Check Last

Modified Date of

Modifie

Generate

byte code

Load byte

Use cached Class

Clear template

Enable trusted

Summary

ColdFusion filter chain has 5 main phases

o Settings in administrator

2. Path Resolution

o Cache web server path setting

o Finding Application.cfc

o Unnamed applications

4. Parsing

o File encoding

5. Bytecode generation

o Template Classloader

Classloading

Class Loading

-Dcoldfusion.classPath = {application.home}/lib/updates, {application.home}/lib,{application.home}/lib/axis2,{application.home}/gateway/lib/,…

In jvm.config

ClassLoader

cfusion/libcfusion/lib/update

cfusion/lib/axis

Prior to CF10

Create a folder in cfusion\lib.

Conflicts

May hamper normal server functioning.

Any changes in jar files need server restart to take effect.

Copy your jars to the new folder.

Edit jvm.config to add the new folder to the end of coldfusion.classPath

property

CF10 and afterwards

CF10 introduced enhanced java integration.

Application setting available to specify custom classpath.

<cfset this.javaSettings = {LoadPaths = [".\java_lib\",".\java\myjar.jar"],

reloadOnChange = false}>

Complete isolation

Will not affect server functioning

Allows reloading

RESTful web services

The W3C defines a Web service as:

A webservice becomes RESTful when the following 4 constraints are

satisfied.

1. Addressability

2. Multiple Representations

3. Uniform and constrained interfaces

4. Stateless communication

a software system designed to support interoperable

machine-to-machine interaction over a network.

How does RESTful web service work?

Two logical sections

Registration

POST /students/StudentsService HTTP/1.1

Host: http://localhost:8500

Content-Type: soap/xml

<Body>

</GetStudent>

</Body>

GET /students/112 HTTP/1.1

Host: http://localhost:8500

Accepts: text/html

Traditional web service

RESTful web service

Registration Workflow

Registration is the process of making your service ready for use.

Register application

Scanning for REST

Generate skeleton

Annotate skeleton

Register with Jersey

Inputs: Application Root Path and Service Name

Settings

Register application

Scanning for REST

• restsettings.cfclocation

Generate skeleton

• restsettings.skipCFCWithError

Annotate skeleton

Register with Jersey

Usage Workflow

Inputs: HTTP request

The URL of the request

HTTP Headers

Body of the request

Query params, Cookies, Matrix params etc..

Explaning the URL

http:// + localhost:8500 + /rest + /examples + /helloworld

• The protocolhttp

• Server address and portlocalhost:8500

• Context path used to identify the request as a REST requestrest

• The application name used during registrationexamples

• restPath defined in the CFChelloworld

Request Workflow

Identify REST

request

Identifies application

Identifies CFC

Identifies function

Invokes Function

Settings

Identify REST

request

• Change context path in web.xml

Identifies application

• Can make application default if needed

Identifies CFC

Identifies function

Invokes Function

• use custom serializer to modify response

Summary

RESTful web services introduction

Why RESTful web service needs to be registered first?

Registration workflow

o Settings

Request Workflow

Settings

pnibinkj@adobe.com

http://blogs.coldfusion.com/

ColdFusion Internals

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