gemfire-core/src/test/java/dunit/RMIException.java

/*=========================================================================
 * Copyright (c) 2010-2014 Pivotal Software, Inc. All Rights Reserved.
 * This product is protected by U.S. and international copyright
 * and intellectual property laws. Pivotal products are covered by
 * one or more patents listed at http://www.pivotal.io/patents.
 *=========================================================================
 */
package dunit;

import com.gemstone.gemfire.GemFireException;

/**
 * This exception is thrown when an exception occurs during a remote
 * method invocation.  This {@link RuntimeException} wraps the actual
 * exception.  It allows distributed unit tests to verify that an
 * exception was thrown in a different VM.
 *
 * <PRE>
 *     VM vm0 = host0.getVM(0);
 *     try {
 *       vm.invoke(this.getClass(), "getUnknownObject");
 *
 *     } catch (RMIException ex) {
 *       assertEquals(ex.getCause() instanceof ObjectException);
 *     }
 * </PRE>
 *
 * Note that special steps are taken so that the stack trace of the
 * cause exception reflects the call stack on the remote machine.
 * The stack trace of the exception returned by {@link #getCause()}
 * may not be available.
 *
 * @see hydra.RemoteTestModuleIF
 *
 * @author David Whitlock
 *
 */
public class RMIException extends GemFireException {

  /** SHADOWED FIELD that holds the cause exception (as opposed to the
   * HokeyException */
  private Throwable cause;

  /** The name of the method being invoked */
  private String methodName;

  /** The name of the class (or class of the object type) whose method
   * was being invoked */
  private String className;

  /** The type of exception that was thrown in the remote VM */
  private String exceptionClassName;

  /** Stack trace for the exception that was thrown in the remote VM */
  private String stackTrace;

  /** The VM in which the method was executing */
  private VM vm;

  ////////////////////////  Constructors  ////////////////////////

  /**
   * Creates a new <code>RMIException</code> that was caused by a
   * given <code>Throwable</code> while invoking a given method.
   */
  public RMIException(VM vm, String className, String methodName,
                      Throwable cause) {
    super("While invoking " + className + "." + methodName + " in " +
          vm, cause);
    this.cause = cause;
    this.className = className;
    this.methodName = methodName;
    this.vm = vm;
  }

  /**
   * Creates a new <code>RMIException</code> to indicate that an
   * exception of a given type was thrown while invoking a given
   * method. 
   *
   * @param vm
   *        The VM in which the method was executing
   * @param className
   *        The name of the class whose method was being invoked
   *        remotely 
   * @param methodName
   *        The name of the method that was being invoked remotely
   * @param cause
   *        The type of exception that was thrown in the remote VM
   * @param stackTrace
   *        The stack trace of the exception from the remote VM
   */
  public RMIException(VM vm, String className, String methodName, 
                      Throwable cause, String stackTrace) {
    super("While invoking " + className + "." + methodName + " in " +
          vm, new HokeyException(cause, stackTrace));
    this.vm = vm;
    this.cause = cause;
    this.className = className;
    this.methodName = methodName;
//    this.exceptionClassName = exceptionClassName; assignment has no effect
    this.stackTrace = stackTrace;
  }

  /**
   * Returns the class name of the exception that was thrown in a
   * remote method invocation.
   */
  public String getExceptionClassName() {
    return this.exceptionClassName;
  }

//   /**
//    * Returns the stack trace for the exception that was thrown in a
//    * remote method invocation.
//    */
//   public String getStackTrace() {
//     return this.stackTrace;
//   }

  /**
   * Returns the cause of this exception.  Note that this is not
   * necessarily the exception that gets printed out with the stack
   * trace.
   */
  public Throwable getCause() {
    return this.cause;
  }

  /**
   * Returns the VM in which the remote method was invoked
   */
  public VM getVM() {
    return this.vm;
  }

  //////////////////////  Inner Classes  //////////////////////

  /**
   * A hokey exception class that makes it looks like we have a real
   * cause exception.
   */
  private static class HokeyException extends Throwable {
    private String stackTrace;
    private String toString;

    HokeyException(Throwable cause, String stackTrace) {
      this.toString = cause.toString();
      this.stackTrace = stackTrace;
    }

    public void printStackTrace(java.io.PrintWriter pw) {
      pw.print(this.stackTrace);
      pw.flush();
    }

    public String toString() {
      return this.toString;
    }
  }
}