gemfire-core/src/test/java/hydra/MethExecutorResult.java

/*=========================================================================
 * Copyright (c) 2002-2014 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
 * more patents listed at http://www.pivotal.io/patents.
 *========================================================================
 */

package hydra;

import java.io.*;

/**
*
* The result of a MethExecutor execute method.
*
*/
public class MethExecutorResult implements Serializable {

  /** A "result" object that indicates that an exception occurred
   * while invoking the method */
  public static final Serializable EXCEPTION_OCCURRED = new
    Serializable() {
      public boolean equals(Object o) {
        // Allows instances to be compared across VMs
        return o != null && this.getClass().equals(o.getClass());
      }

      public String toString() {
        return "EXCEPTION_OCCURRED";
      }
    };

  /** A "exception" object that indicates that an exception could not
   * be serialized. */
  public static final Throwable NONSERIALIZABLE_EXCEPTION = new
    Throwable() {
      public boolean equals(Object o) {
        // Allows instances to be compared across VMs
        return o != null && this.getClass().equals(o.getClass());
      }

      public String toString() {
        return "NONSERIALIZABLE_EXCEPTION";
      }
    };


  ////////////////////  Instance Methods  ///////////////////////////

  /** The result of execution (may be an exception or error type) */
  private Object result;

  /** The exception that resulted from invoking the method */
  private Throwable exception;

  /** Type of the exception (if applicable) */
  private String exceptionClassName;

  /** Message of the exception (if applicable) */
  private String exceptionMessage;

  /** Stack trace information (if applicable) */
  private String stackTrace;

  public MethExecutorResult() {
    this.result = null;
  }

  public MethExecutorResult( Object result ) {
    this.result = result;
  }

  /**
   * This constructor is invoked when invoking a method resulted in an
   * exception being thrown.  The "result" is set to {@link
   * #EXCEPTION_OCCURRED}.  If the exception could not be serialized,
   * {@link #getException()} will return IOException with the exception
   * stack as the message.
   */
  public MethExecutorResult(Throwable thr) {
    this.result = EXCEPTION_OCCURRED;
    this.exceptionClassName = thr.getClass().getName();
    this.exceptionMessage = thr.getMessage();

    StringWriter sw = new StringWriter();

    if (thr instanceof SchedulingOrder) {
      this.stackTrace = "No stack trace for SchedulingOrder\n";
      this.exception = thr;


    } else {
      thr.printStackTrace(new PrintWriter(sw, true));
      this.stackTrace = sw.toString();

      try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        oos.writeObject(thr);
        this.exception = thr;

      } catch (IOException ex) {
        sw = new StringWriter();
        ex.printStackTrace(new PrintWriter(sw, true));
        this.exception = new IOException(sw.toString());
      }
    }
  }

  public String toString() {
    StringBuffer s = new StringBuffer();
    s.append( this.getResult() );
    s.append( "\n" );
    if ( this.getStackTrace() != null ) {
      s.append( this.getStackTrace() );
    }
    return s.toString();
  }

  /**
   * Returns the result of the method call.  If an exception was
   * thrown during the method call, {@link #EXCEPTION_OCCURRED} is
   * returned.
   *
   * @see #exceptionOccurred()
   */
  public Object getResult() {
    return this.result;
  }

  /**
   * Returns the name of the exception class of the exception that
   * was thrown while invoking a method.  If no exception was thrown,
   * <code>null</code> is returned.
   */
  public String getExceptionClassName() {
    return this.exceptionClassName;
  }

  /**
   * Returns the message of the exception that was thrown while
   * invoking a method.  If no exception was thrown, <code>null</code>
   * is returned.
   */
  public String getExceptionMessage() {
    return this.exceptionMessage;
  }

  /**
   * Returns the stack trace of the exception that was thrown while
   * invoking a method.  If no exception was thrown, <code>null</code>
   * is returned.
   */
  public String getStackTrace() {
    return this.stackTrace;
  }

  /**
   * Returns the exception that was thrown while invoking a method.
   * If the exception could not be serialized, then {@link
   * #NONSERIALIZABLE_EXCEPTION} is returned.  If no exception was
   * thrown, <code>null</code> is returned.
   */
  public Throwable getException() {
    return this.exception;
  }

  /**
   * Returns whether or not an exception occurred while invoking the
   * method 
   */
  public boolean exceptionOccurred() {
    return EXCEPTION_OCCURRED.equals(this.result);
  }

}