Http:// Doug Hughes, Alagad Inc. Drinkin’ Cold Coffee -or- How to use Java Objects from ColdFusion

Doug Hughes, Alagad Inc. Doug Hughes, Alagad Inc. http://www.alagad.comhttp://www.alagad.com

Drinkin’ Cold CoffeeDrinkin’ Cold Coffee

-or--or-

How to use Java Objects from How to use Java Objects from ColdFusion.ColdFusion.


What are you going to What are you going to learn?learn?

Why you might want to use Java objects Why you might want to use Java objects from ColdFusion.from ColdFusion.

How to instantiate Java objects from How to instantiate Java objects from ColdFusion MX.ColdFusion MX.

How to call the constructors of Java objects.How to call the constructors of Java objects. How to call methods on Java objects.How to call methods on Java objects. The advantages of using Java (as opposed The advantages of using Java (as opposed

to CFX tags, etc)to CFX tags, etc) Potential problems and their solutions.Potential problems and their solutions.


What can you do with Java?What can you do with Java?

Use strong encryption.Use strong encryption. Manipulate Images.Manipulate Images. Edit audio clips.Edit audio clips. Zip and Unzip files.Zip and Unzip files. Create network socket connections.Create network socket connections. Low level programming.Low level programming. Almost anything you can do with the Java Almost anything you can do with the Java

language.language.


Why do you care about Why do you care about Java?Java?

ColdFusion is written in JavaColdFusion is written in Java Macromedia has been pushing CF deployment Macromedia has been pushing CF deployment

on J2EE serverson J2EE servers In short, an easy way to write J2EE applications.In short, an easy way to write J2EE applications.

In short, ColdFusion is a friendly version of In short, ColdFusion is a friendly version of Java.Java.

ColdFusion provides an easy way to use Java ColdFusion provides an easy way to use Java without requiring extensive knowledge of Java.without requiring extensive knowledge of Java.

Blackstone may deploy ColdFusion Blackstone may deploy ColdFusion applications as WAR files on J2EE.applications as WAR files on J2EE.


Where to find the Java DocsWhere to find the Java Docs

http://java.sun.com/j2se/1.4.2/docs/ahttp://java.sun.com/j2se/1.4.2/docs/api/index.htmlpi/index.html

The hardest part of using Java is The hardest part of using Java is learning how to read the learning how to read the documentation.documentation.


How to invoke Java objectsHow to invoke Java objects

CreateObject()CreateObject()<cfset myZip = CreateObject("Java", <cfset myZip = CreateObject("Java", "java.util.zip.ZipFile") />"java.util.zip.ZipFile") />

<cfobject><cfobject><cfobject<cfobject

type="Java"type="Java"action="Create"action="Create"class="java.util.zip.ZipFile"class="java.util.zip.ZipFile"name="myZip" />name="myZip" />


Typing in Java vs. Typing in Java vs. ColdFusionColdFusion

Java is a strongly typed languageJava is a strongly typed language This means the language always knows what This means the language always knows what

type a variable istype a variable is ColdFusion is a typeless language. ColdFusion is a typeless language.

This means any variable can be a string, This means any variable can be a string, integer, query, whatever.integer, query, whatever.

Because ColdFusion is typeless, CF has to Because ColdFusion is typeless, CF has to guess what type of data you are passing guess what type of data you are passing into Java object methods.into Java object methods.

If ColdFusion passes an incorrect type into If ColdFusion passes an incorrect type into a Java method you will get errors.a Java method you will get errors.


An example typing errorAn example typing error


Use JavaCast() to type CF Use JavaCast() to type CF variablesvariables

You can use JavaCast() to type data You can use JavaCast() to type data being passed into Java methods.being passed into Java methods.

Casts data from ColdFusion to Java.Casts data from ColdFusion to Java. Intended for calling overloaded Java Intended for calling overloaded Java

Methods.Methods. Syntax:Syntax:JavaCast(JavaCast(typetype, , variablevariable))


How to init Java objectsHow to init Java objects

Most Java objects require that you Most Java objects require that you call a constructor to configure call a constructor to configure objects for use.objects for use.

Use “.init()” to call constructors on Use “.init()” to call constructors on Java objects.Java objects.


Calling Object ConstructorsCalling Object Constructors

To instantiate a Java zipFile object you have To instantiate a Java zipFile object you have to call one of three constructorsto call one of three constructors http://java.sun.com/j2se/1.4.2/docs/api/java/util/zhttp://java.sun.com/j2se/1.4.2/docs/api/java/util/z

ip/ZipFile.htmlip/ZipFile.html

Example:Example:<cfset pathToZip = "c:\example.zip" /><cfset pathToZip = "c:\example.zip" /><cfset myZip = CreateObject("Java", <cfset myZip = CreateObject("Java", "java.util.zip.ZipFile") />"java.util.zip.ZipFile") />

<cfset myZip.init(JavaCast("string",pathToZip)) /><cfset myZip.init(JavaCast("string",pathToZip)) />


What happens when you don’t What happens when you don’t init an object?init an object?

<cfset FileInputStream = CreateObject("Java", <cfset FileInputStream = CreateObject("Java", "java.io.FileInputStream") />"java.io.FileInputStream") />

<cfset FileInputStream.read() /><cfset FileInputStream.read() />


What happens when you don’t What happens when you don’t init an object?init an object?


What happens when there are What happens when there are other problems initing your other problems initing your

object?object?


Calling Java Object methodsCalling Java Object methods

We can call methods of the myZip We can call methods of the myZip object to perform various actions.object to perform various actions. http://java.sun.com/j2se/1.4.2/docs/api/jhttp://java.sun.com/j2se/1.4.2/docs/api/j

ava/util/zip/ZipFile.html#getInputStreamava/util/zip/ZipFile.html#getInputStream(java.util.zip.ZipEntry)(java.util.zip.ZipEntry)

For instance:For instance:<cfoutput>The Zip File "#myZip.getName()#" contains #myZip.size()# files.

</cfoutput>


Another (more complex) Another (more complex) exampleexample

Get a list of files in the myZip objectGet a list of files in the myZip object

<cfset zipFiles = myZip.entries() /><cfset zipFiles = myZip.entries() />

<cfloop condition="#zipFiles.hasMoreElements()#"><cfloop condition="#zipFiles.hasMoreElements()#">

<cfset myZipEntry = zipFiles.nextElement() /><cfset myZipEntry = zipFiles.nextElement() /><cfoutput><cfoutput>

#myZipEntry.getName()##myZipEntry.getName()#(#myZipEntry.getSize()# Bytes) (#myZipEntry.getSize()# Bytes) 

</cfoutput></cfoutput></cfloop></cfloop>


Results so farResults so far

<cfset pathToZip = "c:\example.zip" /><cfset pathToZip = "c:\example.zip" /><cfset myZip = CreateObject("Java", <cfset myZip = CreateObject("Java",

"java.util.zip.ZipFile") />"java.util.zip.ZipFile") /><cfset myZip.init(JavaCast("string", <cfset myZip.init(JavaCast("string",

pathToZip)) />pathToZip)) />

<cfoutput><cfoutput>The Zip File "#myZip.getName()#" contains The Zip File "#myZip.getName()#" contains

#myZip.size()# files.#myZip.size()# files.</cfoutput></cfoutput>

<cfset zipFiles = myZip.entries() /><cfset zipFiles = myZip.entries() />

Enumeration --->

<cfloop <cfloop condition="#zipFiles.hasMoreElements()#">condition="#zipFiles.hasMoreElements()#"><cfset myZipEntry = <cfset myZipEntry = zipFiles.nextElement() />zipFiles.nextElement() /><cfoutput><cfoutput>

#myZipEntry.getName()# #myZipEntry.getName()# (#myZipEntry.getSize()# Bytes) (#myZipEntry.getSize()# Bytes) </cfoutput></cfoutput>

</cfloop></cfloop>


Using <cfdump> to get more Using <cfdump> to get more information on Java Objectsinformation on Java Objects

You can use <cfdump> on any ColdFusion You can use <cfdump> on any ColdFusion variable.variable.

If the variable a Java object you get:If the variable a Java object you get: The object type nameThe object type name The object’s methodsThe object’s methods The object’s propertiesThe object’s properties

Example:Example:<cfset FileInputStream = CreateObject("Java", <cfset FileInputStream = CreateObject("Java",

"java.io.FileInputStream") />"java.io.FileInputStream") />

<cfset FileInputStream.init("c:\Collin 4 copy.jpg") /><cfset FileInputStream.init("c:\Collin 4 copy.jpg") />

<cfdump var="#FileInputStream#"><cfdump var="#FileInputStream#">


Results from the dumpResults from the dump

Can be helpful in Can be helpful in figuring out what an figuring out what an object is and what object is and what methods it provides.methods it provides.

Helps support the Helps support the Java documentation.Java documentation.

Another dump Another dump example: example: http://http://alagad.com/JavaFromalagad.com/JavaFromCF/cfdump.cfmCF/cfdump.cfm


Wrapping Java in CFCsWrapping Java in CFCs

You can use CFCs to wrap Java You can use CFCs to wrap Java objects.objects.

Provides easier access to complex Provides easier access to complex Java objects.Java objects.

Extremely reusable and cross Extremely reusable and cross platform.platform.


Let’s look at a simple Zip Let’s look at a simple Zip CFCCFC

Create Zip filesCreate Zip files Add files to Zip filesAdd files to Zip files

Return a query of all the files in a Zip Return a query of all the files in a Zip filefile NameName If the entry is a directoryIf the entry is a directory Uncompressed sizeUncompressed size Compressed sizeCompressed size

Extract files from the zipExtract files from the zip


Alagad Image ComponentAlagad Image Component

A good example of wrapping Java in CFCs.A good example of wrapping Java in CFCs. 100% native ColdFusion Component (CFC) 100% native ColdFusion Component (CFC)

used to create and manipulate image files used to create and manipulate image files by invoking and calling methods on Java by invoking and calling methods on Java objects.objects.

Over 60 methods for working with Images.Over 60 methods for working with Images. Platform independent.Platform independent. Makes lots of use of Java from within Makes lots of use of Java from within

ColdFusion.ColdFusion. http://alagad.com/index.cfm/name-aichttp://alagad.com/index.cfm/name-aic


Advantages of using Java in Advantages of using Java in ColdFusionColdFusion

Cross PlatformCross Platform Write code on any platform and deploy Write code on any platform and deploy

to any platform.to any platform. The power of Java at your fingertips.The power of Java at your fingertips. It’s Free!It’s Free! It’s not CFX!It’s not CFX!


What did you learn?What did you learn? Why you might want to use Java objects Why you might want to use Java objects

from ColdFusion.from ColdFusion. How to instantiate Java objects from How to instantiate Java objects from

ColdFusion MX.ColdFusion MX. How to call the constructors of Java objects.How to call the constructors of Java objects. How to call methods on Java objects.How to call methods on Java objects. The advantages of using Java (as opposed The advantages of using Java (as opposed

to CFX tags, etc)to CFX tags, etc) Potential problems and their solutions.Potential problems and their solutions. That you really need to by the Alagad Image That you really need to by the Alagad Image

Component.Component.

Documents

Http:// Doug Hughes, Alagad Inc. Drinkin’ Cold Coffee -or- How to use Java Objects from ColdFusion