Class Loaders

Each plugin has a dedicated class loader, which is used to load the plugin's classes. This allows each plugin to use a different library version, even if the same library is used by the IDE itself or by another plugin.

Overriding IDE Dependencies

Gradle 7 introduced the implementation scope that replaced the compile scope. For this setup, to use a library dependency declared by a plugin instead of the version bundled in the IDE, add the following snippet to the Gradle build script:

configurations.all {
  resolutionStrategy.sortArtifacts(ResolutionStrategy.SortOrder.DEPENDENCY_FIRST)
}

Loading Classes from Plugin Dependencies

By default, the main IDE class loader loads classes that are not found in the plugin class loader. However, in the plugin.xml file, you may use the <depends> element to specify that a plugin depends on one or more other plugins. In this case, the class loaders of those plugins will be used for classes not found in the current plugin. This allows a plugin to reference classes from other plugins.

Using `ServiceLoader`

Some libraries use ServiceLoader to detect and load implementations. To make it work in a plugin, the context class loader must be set to the plugin's classloader and restored afterward with the original one around initialization code:

val currentThread = Thread.currentThread()
val originalClassLoader = currentThread.contextClassLoader
val pluginClassLoader = this.javaClass.classLoader
try {
  currentThread.contextClassLoader = pluginClassLoader
  // code working with ServiceLoader here
} finally {
  currentThread.contextClassLoader = originalClassLoader
}

Thread currentThread = Thread.currentThread();
ClassLoader originalClassLoader = currentThread.getContextClassLoader();
ClassLoader pluginClassLoader = this.getClass().getClassLoader();
try {
  currentThread.setContextClassLoader(pluginClassLoader);
  // code working with ServiceLoader here
} finally {
  currentThread.setContextClassLoader(originalClassLoader);
}

18 June 2025

Class Loaders

Overriding IDE Dependencies

Loading Classes from Plugin Dependencies

Using ServiceLoader

Using `ServiceLoader`