JRE deinstrumentation

Note JRE instrumentation has been obsolete for a long time now and can even cause problems. The following section remains only to provide background information and to show how to remove an existing JRE instrumentation without re-installing the JRE.

Note To remove instrumentation of a JRE you need write permission for some of its directories, so you may have to work with administrator privileges to perform this step.

When instrumenting the JRE QF-Test made use of the official accessibility interface which is provided by Java for just this purpose. It can be used by accessibility and capture replay tools to interact with Java applications without those applications knowing about it and without requiring any changes to those applications.

To activate this interface, QF-Test created or modified the file .../lib/accessibility.properties in the JRE installation and added the class de.qfs.apps.qftest.start.Connector to the property "assistive_technologies". This has the effect that this class will be instantiated whenever the AWT toolkit is initialized in any Java application or applet that is run with this JRE.

To make sure that this class can always be found without modifications to the CLASSPATH, the file qfconnect.jar, which contains the Connector class, was placed in the Java extensions directory .../lib/ext.

To deinstrument the JRE, first remove the entry for .../lib/accessibility.properties from the "assistive_technologies" property in .../lib/accessibility.properties so that the Connector class will no longer be used. Next delete the file qfconnect.jar from the .../lib/ext directory of the JRE which is possible only when no Java program is currently being run with this JRE.