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Using JDK Tools Under MRJ 2.2

Q: When I try to use tools from the MRJ SDK 2.2, I cannot get them to run because it thinks I don't have the right classes installed. What's the problem? This used to work just fine under MRJ 2.1.4 and earlier.

A: You are most likely seeing a either a dialog similar to this:

launch error

or a message in the console similar to this:

java.lang.NoClassDefFoundError: sun/tools/javac/Main
    at com.apple.mrj.sdk.apps.Javac.invokeCoreTool(Javac.java)
    at com.apple.mrj.sdk.apps.JDKTool.executeTool(JDKTool.java)
    at com.apple.mrj.sdk.apps.JDKTool$1.actionPerformed(JDKTool.java)
    at java.awt.Button.processActionEvent(Button.java)
    at java.awt.Button.processEvent(Button.java)
    at java.awt.Component.dispatchEventImpl(Component.java)
    at java.awt.Component.dispatchEvent(Component.java)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java)

The dialog is a result of not having the "MRJSDKClasses.zip" in your MRJClasses folder and MRJ cannot locate the main class from which to launch the tool.

The console stack trace message is a result of not having the "JDKToolsClasses.zip" in your MRJClasses folder, and MRJ cannot locate the underlying support classes for the tool.

In order to make the MRJ installation more streamlined in MRJ 2.2, the most commonly used classes are installed automatically, while some of the more abstract, or developer-level, classes have been separated out into additional zip files. The "MRJSDK:Extensions" folder contains Java classes you may need at runtime. MRJ does not use these classes for normal applications and applets. They include "MRJSDKClasses.zip", "JDKToolsClasses.zip", and "JDKI18nClasses.zip."

MRJSDKClasses.zip
MRJSDKClasses.zip is required for running the JDK tools.

JDKToolsClasses.zip
JDKToolsClasses.zip is required for running the JDK tools. The classes in this file were formerly included in the MRJ 2.1.x installation.

JDKI18nClasses.zip
You will need this file only if you want to use Sun's char-to-byte and byte-to-char converter classes directly for various localized scripts. The classes in this file were formerly included in the MRJ 2.1.x installation.

Earlier versions of the MRJ SDK 2.1 Installer installed two files which are no longer needed. If they still exist on your system, you need to remove them manually. They include:

  • "Properties.zip" (remove from the MRJ Libraries:MRJClasses folder)
  • "MRJSDKLib" (remove from the MRJ Libraries folder)

The MRJ SDK 2.2 installer will automatically place the "MRJSDKClasses.zip" and "JDKToolsClasses.zip" in the MRJClasses folder of the active System folder.

[Feb 02 2000]

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