/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License. You may obtain a
* copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
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);
}
}