org.eclipse.contribution.xref.core/src/org/eclipse/contribution/xref/ras/PluginFFDC.aj

/*******************************************************************************
 * Copyright (c) 2005 IBM Corporation and others. All rights reserved. This
 * program and the accompanying materials are made available under the terms of
 * the Eclipse Public License v1.0 which accompanies this distribution, and is
 * available at http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: IBM Corporation - initial API and implementation 
 * 				 Helen Hawkins   - iniital version
 ******************************************************************************/
package org.eclipse.contribution.xref.ras;

import java.lang.reflect.Field;
import java.util.LinkedList;
import java.util.List;

import org.aspectj.lang.JoinPoint;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.MultiStatus;
import org.eclipse.core.runtime.Status;

/**
 * PluginFFDC aspect - a duplicate of org.eclipse.ajdt.ras.PluginFFDC until longer
 * term solution is in place
 */
public abstract aspect PluginFFDC extends FFDC {

    /** 
     * Template method to obtain plug-in ID for IStatus objects
     * 
     * @return String e.g. "org.eclipse.ajdt.core"
     */ 
    protected abstract String getPluginId ();
    
    /** 
     * Template method to consume FFDC
     */ 
    protected abstract void log (IStatus status);
    
    protected void processStaticFFDC (Throwable th, String sourceId) {
    	logException(th,sourceId,null);
    }

    protected void processNonStaticFFDC (Throwable th, Object obj, String sourceId) {
    	logException(th,sourceId,obj);
    }
    
	/**
	 * Build IStatus messages contain details of caught exception, where it was
	 * caught and the object (if any) that caught it
	 */
	public void logException (Throwable th, String sourceId, Object obj) {
		IStatus status = null;
		if (th instanceof CoreException) {
			status = ((CoreException) th).getStatus();
		} else {
			try {
				IStatus sourceChild = new Status(IStatus.ERROR,getPluginId(),IStatus.OK,sourceId,null);
				String message = th.getMessage();
				if (message == null) {
					message = th.toString();
				}

				IStatus[] children;
				if (obj == null) {
					children = new IStatus[] { sourceChild };
				}
				else {
					IStatus objectChild = introspect(obj);
					children = new IStatus[] { sourceChild, objectChild };
				}
				
				status = new MultiStatus(getPluginId(),IStatus.OK,children,message,th);
			}
			catch (Exception ex) {
				status = new Status(IStatus.ERROR,getClass().getName(),IStatus.OK,sourceId,th);
			}
		}
		log(status);
	}

	/**
	 * Obtain object identity and class as well as field values
	 * 
	 * @param obj Object to be introspected
	 * @return MultiStatus object
	 */
	private IStatus introspect (Object obj) {
		final Class sjpClass = JoinPoint.StaticPart.class;
		String message;
		List fieldValues = new LinkedList();
		IStatus[] fieldValuesArray;

		/* Handle any NullPointerExceptions */
		try {
			message = obj.toString();
		}
		catch (Exception ex) {
			message = safeToString(obj);
		}
		
		/* Handle any SecurityExceptions */
		try {
			Field[] fields = obj.getClass().getDeclaredFields();
			
			for (int i = 0; i < fields.length; i++) {
				Field field = fields[i];
				field.setAccessible(true);
				/* Omit static join point fields */
				if (!sjpClass.isAssignableFrom(field.getType())) {
					Object value = field.get(obj);
					String fieldMessage = field.getName() + "=" + safeToString(value); //$NON-NLS-1$
					fieldValues.add(new Status(IStatus.INFO,getPluginId(),IStatus.OK,fieldMessage,null));
				}
			}

			fieldValuesArray = new IStatus[fieldValues.size()];
			fieldValues.toArray(fieldValuesArray);
		}
		catch (Exception ex) {
			fieldValuesArray = new IStatus[] {};
		}

		IStatus result = new MultiStatus(getPluginId(),IStatus.INFO,fieldValuesArray,message,null);
		return result;
	}
	
	private static String safeToString (Object obj) {
		if (obj == null) return "null"; //$NON-NLS-1$
		else if (obj instanceof String) return "\"" + obj.toString() + "\""; //$NON-NLS-1$ //$NON-NLS-2$
		else return (obj.getClass() + "@" + obj.hashCode()); //$NON-NLS-1$
	}
}