org.aspectj/org.aspectj.matcher/src/main/java/org/aspectj/weaver/tools/TraceFactory.java

/*******************************************************************************
 * Copyright (c) 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.txt
 *
 * Contributors:
 *     Matthew Webster - initial implementation
 *******************************************************************************/
package org.aspectj.weaver.tools;

public abstract class TraceFactory {

	public final static String DEBUG_PROPERTY = "org.aspectj.tracing.debug";
	public final static String FACTORY_PROPERTY = "org.aspectj.tracing.factory";
	public final static String DEFAULT_FACTORY_NAME = "default";

    protected static boolean debug = getBoolean(DEBUG_PROPERTY,false);
    private static TraceFactory instance;

    public Trace getTrace (Class clazz) {
    	return instance.getTrace(clazz);
    }

    public static TraceFactory getTraceFactory () {
    	return instance;
    }

    protected static boolean getBoolean(String name, boolean def) {
		String defaultValue = String.valueOf(def);
		String value = System.getProperty(name,defaultValue);
		return Boolean.parseBoolean(value);
	}

	static {

		/*
		 * Allow user to override default behaviour or specify their own factory
		 */
		String factoryName = System.getProperty(FACTORY_PROPERTY);
		if (factoryName != null) try {
			if (factoryName.equals(DEFAULT_FACTORY_NAME)) {
				instance = new DefaultTraceFactory();
			}
			else {
	    		Class factoryClass = Class.forName(factoryName);
	    		instance = (TraceFactory)factoryClass.getDeclaredConstructor().newInstance();
			}
		}
    	catch (Throwable th) {
    		if (debug) th.printStackTrace();
    	}

		/*
		 * Try to load external trace infrastructure using supplied factories
		 */
    	if (instance == null) try {
			{
	    		Class factoryClass = Class.forName("org.aspectj.weaver.tools.Jdk14TraceFactory");
	    		instance = (TraceFactory)factoryClass.getDeclaredConstructor().newInstance();
			}
    	}
    	catch (Throwable th) {
    		if (debug) th.printStackTrace();
    	}

    	/*
		 * Use default trace
		 */
    	if (instance == null) {
    	    instance = new DefaultTraceFactory();
    	}

    	if (debug) System.err.println("TraceFactory.instance=" + instance);
    }

}