Dependency between Eclipse plug-ins, export jar package installation, error "Java.lang.NoClassDefFoundError"

In the process of developing plug-in a and plug-in B, Plugin a needs to use a class ClassB to Plugin B, assuming ClassB is located in Plugin b Packageb,

Then you need to add the Manifest.mf file in plugin B:

Export-package:  Packageb

and add in plugin B's MANIFEST.MF file:

Import-package:  Packageb

This declares the dependency relationship.

After exporting the jar packages of two plugins separately, after copying them into Eclipse's/plugin directory, run Eclipse and discover that two plug-ins can function independently, but when Pluga calls CLASSB, the system error:

1 Java.lang.noclassdeffounderror:org/jboss/tools/vpe/browsersim/eclipse/launcher/browsersimlauncher2 At Org.ayound.js.debug.launch.JsLaunchConfigurationDelegate.launch (jslaunchconfigurationdelegate.java:101) 3 At org.eclipse.debug.internal.core.LaunchConfiguration.launch (launchconfiguration.java:858)4 At org.eclipse.debug.internal.core.LaunchConfiguration.launch (launchconfiguration.java:707)5 At org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch (debuguiplugin.java:1018)6 At Org.eclipse.debug.internal.ui.debuguiplugin$8.run (debuguiplugin.java:1222)7 At Org.eclipse.core.internal.jobs.Worker.run (worker.java:53)8 caused by:java.lang.ClassNotFoundException: Org.jboss.tools.vpe.browsersim.eclipse.launcher.BrowserSimLauncher cannot be found by org.ayound.js.debug.core_ 2.2.09 At org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal (bundleloader.java:501)Ten At Org.eclipse.osgi.internal.loader.BundleLoader.findClass (bundleloader.java:421) One At Org.eclipse.osgi.internal.loader.BundleLoader.findClass (bundleloader.java:412) A At Org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass (defaultclassloader.java:107) - At Java.lang.ClassLoader.loadClass (classloader.java:358) -... 6 more

Plugina (in this case, org.ayound.js.debug.core_2.2.0) cannot find the CLASSB of PLUGINB (in this case, Org.jboss.tools.vpe.browsersim.eclipse) ( BROWSERSIMLAUNCHER.CLASS)!!

It took a long time to find a solution: Add the "-clean" option when you start Eclipse .

You can modify the Eclipse.ini file or command line startup, under the Windows platform, you can find Eclipse.exe, right-click Create shortcut, and then right-clicking on the shortcut icon, properties---"... Eclipse.exe "Then add"-clean "and double-click the shortcut to run Eclipse.

Why start with the option "-clean"?

Because this indicates that all dependencies on the plug-in when Eclipse starts are rebuilt instead of using the previous cached content .

Please refer to StackOverflow

Dependency between Eclipse plug-ins, export jar package installation, error "Java.lang.NoClassDefFoundError"