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Extensions - Java Applets

Manage Java applet registration and settings

Last updated: October 27, 20256 min read

Overview

The Java Applets section in ColdFusion Administrator allows you to register and configure Java applets that can be embedded in web pages using the <cfapplet> tag. This feature simplifies the HTML code needed to embed Java applets by pre-configuring applet parameters.

Deprecated Technology: Java applets are obsolete technology no longer supported by modern browsers. Most browsers removed Java plugin support in 2015-2017 due to security concerns. This feature exists only for legacy system maintenance. For new projects, use modern alternatives like JavaScript, WebAssembly, or HTML5.

Java Applet Technology Background

Understanding the legacy Java applet technology and why it's no longer used.

What Were Java Applets?

PurposeSmall Java programs embedded in web pages and executed in the browser

TechnologyRequired Java browser plugin to run

Peak Usage1995-2010 for rich internet applications

StatusDeprecated by Oracle in 2017, removed from browsers

Historical Context: Java applets were popular for adding interactive features like animations, calculators, games, and data visualizations before modern JavaScript frameworks and HTML5 APIs became available.

Why Applets Were Deprecated

Reasons for Deprecation:

Security Vulnerabilities: Frequent zero-day exploits and malware distribution
Performance Issues: Slow loading times and high resource consumption
Browser Support: Major browsers removed Java plugin support
Better Alternatives: HTML5, JavaScript, and WebAssembly provide better solutions
Mobile Incompatibility: Never worked on iOS/Android mobile browsers
Maintenance Burden: Required users to install and update Java plugin

Modern Alternatives

Replace Java Applets With:

JavaScript Frameworks: React, Vue, Angular for interactive UIs
HTML5 Canvas/SVG: Rich graphics and animations
WebGL: 3D graphics and visualizations
WebAssembly: High-performance compiled code in browsers
Web Components: Reusable custom elements
Progressive Web Apps: App-like experiences in browsers
Native Apps: For mobile devices, use native or React Native

Registering Java Applets (Legacy)

Historical reference for systems that still require Java applet support.

Applet Name

PurposeUnique identifier for the registered applet

FormatAlphanumeric string without spaces

ExampleChartApplet, CalculatorWidget

Code

PurposeFully qualified Java class name of the applet

Formatcom.company.package.AppletClassName.class

Examplecom.example.charts.LineChart.class

Codebase

PurposeURL path where the applet class files are located

FormatRelative or absolute URL path

Example/applets/, https://cdn.example.com/java/

Archive (JAR Files)

PurposeJAR file(s) containing the applet classes

FormatComma-separated list of JAR filenames

Examplechart.jar, common.jar

Width & Height

PurposeDisplay dimensions of the applet in pixels or percentage

Example600 (pixels) or 100%

VSpace & HSpace

PurposeVertical and horizontal spacing around the applet in pixels

Default0 pixels

Align

PurposeAlignment of applet relative to surrounding content

OptionsLeft, Right, Top, Bottom, Middle, Baseline

Using cfapplet Tag (Legacy)

Historical reference for the <cfapplet> tag:

cfapplet Tag Usage (Deprecated)

<!--- DEPRECATED: Will not work in modern browsers --->
<cfapplet
  appletsource="ChartApplet"
  name="myChart"
  width="600"
  height="400">

<!--- Pass parameters to applet --->
<cfapplet
  appletsource="ChartApplet"
  name="myChart"
  width="600"
  height="400"
  param_dataURL="data.xml"
  param_chartType="line">

<!-- What cfapplet generated (legacy HTML) -->
<applet
  code="com.example.charts.LineChart.class"
  codebase="/applets/"
  archive="chart.jar"
  width="600"
  height="400"
  name="myChart">
  <param name="dataURL" value="data.xml">
  <param name="chartType" value="line">
  Your browser does not support Java applets.
</applet>

Warning: This code will not work in any modern browser. Java plugin support was removed from Chrome (2015), Firefox (2016), Edge (2016), and Safari (2017).

Migration Path

Identifying Applet Usage

Search Your Codebase:

Search for <cfapplet tags in CFML templates
Look for <applet tags in HTML files
Check for .jar files in web directories
Review ColdFusion Administrator Java Applets section
Identify what functionality each applet provides

Migration Strategies

Replace Applets With:

Charting: Use Chart.js, D3.js, or Highcharts
File Upload: HTML5 file input with drag-and-drop
Image Editing: Canvas API with libraries like Fabric.js
Data Entry: Modern JavaScript form controls
Real-time Updates: WebSockets or Server-Sent Events
Complex UI: React, Vue, or Angular components
File Signing: Server-side digital signatures

Testing After Migration

Validation Checklist:

Test functionality in all target browsers
Verify mobile device compatibility
Ensure feature parity with original applet
Test with various screen sizes and resolutions
Validate accessibility (keyboard navigation, screen readers)
Check performance and load times
Remove applet JAR files and configurations after successful migration

Common Applet Replacements

Charting Applets

Modern Alternative: Chart.js, D3.js, Highcharts, Apache ECharts
Benefits: Interactive, responsive, no plugins required

JavaScript charting libraries provide better interactivity and work on all devices.

File Upload Applets

Modern Alternative: HTML5 File API, Dropzone.js, Uppy
Benefits: Drag-and-drop, multiple files, progress bars

Modern upload libraries support chunked uploads and resume capabilities.

Rich Text Editors

Modern Alternative: TinyMCE, CKEditor, Quill, ProseMirror
Benefits: Better UX, mobile support, extensible

JavaScript editors provide WYSIWYG editing without plugins.

Image Manipulation

Modern Alternative: Canvas API, Fabric.js, Konva.js
Benefits: Hardware acceleration, touch support

Canvas provides powerful image editing capabilities in the browser.

PDF Viewers

Modern Alternative: PDF.js, browser native PDF viewer
Benefits: No plugins, built into browsers

Modern browsers include native PDF viewing capabilities.

Real-time Updates

Modern Alternative: WebSockets, Server-Sent Events
Benefits: Bidirectional, low latency, efficient

WebSockets provide real-time communication without polling.

Cleanup and Removal

Removing Applet Configurations

Steps:

Remove applet registrations from ColdFusion Administrator
Delete <cfapplet> tags from CFML templates
Remove applet JAR files from web directories
Delete unused Java applet documentation
Update any references in wikis or documentation
Remove from deployment scripts and version control

Related Resources

Server Settings - Java & JVMJava configuration for ColdFusion applications ColdFusion Administrator ReferenceComplete administrator guide and settings reference