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IcedTea-Web Usage Instructions

Table of Contents
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Validate Installation on Windows

Java 8

Make sure you have Java 8.

 
C:\>java -version
openjdk version "1.8.0_402"
OpenJDK Runtime Environment (Zulu 8.76.0.17-CA-win64) (build 1.8.0_402-b06)
OpenJDK 64-Bit Server VM (Zulu 8.76.0.17-CA-win64) (build 25.402-b06, mixed mode)

JAVA_HOME

Check that the JAVA_HOME variable has been defined and points to the correct location of the Java installation.

 
C:\>echo %JAVA_HOME%
C:\Program Files\Zulu\zulu-8\

IcedTea-Web in PATH variable

Check that the IcedTea-Web directory has been added to a PATH variable.

 
C:\>echo %PATH%
C:\Program Files\IcedTeaWeb\WebStart\bin;C:\Program Files\Zulu\zulu-8\bin\;C:\Windows\system32;C:\Windows;...

How to Start a WebStart Application

In modern browsers, a JNLP-file is downloaded and saved to the downloads folder, and can’t be opened in the browser.

Once a JNLP-file has been downloaded, you can start it in several ways.

On Windows

  • Open the Downloads directory and double-click on the JNLP-file.

    • This only works if there is an association between the .jnlp extension and the javaws.exe binary.

  • Start a JNLP-file from the command line:

     
    C:\Users\YourName\Downloads>javaws application.jnlp

  • Use the full installation path of javaws.exe:

     
    C:\Users\YourName\Downloads>"C:\Program Files\IcedTeaWeb\WebStart\bin\javaws.exe" application.jnlp

On macOS

The default security settings of macOS prohibit JNLP apps from launching. To solve this, follow these steps:

  • Go to System Settings > Privacy & Security.

  • Select Allow applications downloaded from > App Store and identified developers.

  • When you already tried to open a .jnlp file and it was blocked by macOS, it will be shown on this screen and you can click on Open Anyway.

  • Right-click on the downloaded file and select Open With. Select Azul IcedTea-Web instead of JavaLauncher.

  • From now on, you can open such a file by double-clicking it.

macos open anyway

Additional Tools

A few other tools are provided with IcedTea-Web.

Web Control Panel

itweb-settings: allows to view and modify the settings for javaws and the browser plugin.

 
C:\>itweb-settings
web control panel

PolicyEditor

policyeditor: allows end-users to quickly and easily view or edit the contents of their applet policy.

 
C:\>policyeditor
policy editor

How IcedTea-Web is Locating the Java Runtime

javaws.exe needs a valid Java Runtime, and it searches for this runtime in the following order, until it finds it:

  1. Check deployment.properties for the deployment.jre.dir property.

  2. Check the JAVA_HOME environmental variable.

  3. Check if there is an embedded Java Runtime with IcedTea-Web.

  4. Check Windows registry keys.

  5. Check if there is a Java Runtime in the PATH variable.