package top.infra.test.classloader;
   
   import org.junit.runner.Description;
   import org.junit.runner.Runner;
   import org.junit.runner.notification.RunNotifier;
   import org.junit.runners.BlockJUnit4ClassRunner;
   
   /**
    * see: https://arnaudroger.github.io/blog/2016/07/18/testing-with-custom-classpath.html
   * see: https://github.com/arnaudroger/blog/tree/master/src/main/java/io/github/arnaudroger/tmvl
   */
  public class ClassLoaderChangerRunner extends Runner {
  
      private final ClassLoader currentClassLoader;
      private final ClassLoader customClassLoader;
      private final BlockJUnit4ClassRunner delegate;
  
      public ClassLoaderChangerRunner(
          final ClassLoader currentClassLoader,
          final ClassLoader customClassLoader,
          final BlockJUnit4ClassRunner delegate
      ) {
          this.currentClassLoader = currentClassLoader;
          this.customClassLoader = customClassLoader;
          this.delegate = delegate;
      }
  
      @Override
      public Description getDescription() {
          return this.delegate.getDescription();
      }
  
      @Override
      public void run(final RunNotifier runNotifier) {
          try {
              Thread.currentThread().setContextClassLoader(this.customClassLoader);
              this.delegate.run(runNotifier);
          } finally {
              Thread.currentThread().setContextClassLoader(this.currentClassLoader);
          }
      }
  }