Turn synchronous log4j (1.x) logger into asynchronous

AsyncAppenderBuilder

import org.apache.log4j.Appender
import org.apache.log4j.AsyncAppender
import org.slf4j.impl.Log4jLoggerAdapter

/**
 * Replaces the original sync appender with an async appender
 * @author arrizabalaga
 */
class AsyncAppenderBuilder {
	
	private static int DEFAULT_BUFFER_SIZE=500

	/**
	 * Looks for an appender in the logger, wraps it with an async and deletes the original appender.
	 * @param loggerAdapter slf4j logger adapter
	 * @param nombreAppender name of the sync appender to be wrapped
	 */
	static void wrapAsyncAppender(Log4jLoggerAdapter loggerAdapter,String appenderName,int bufferSize=DEFAULT_BUFFER_SIZE) {
		//Take original appender
		org.apache.log4j.Logger log4jLogger=loggerAdapter.logger
		Appender syncAppender=log4jLogger.getAppender(appenderName)
		
		//Wrap it
		AsyncAppender asyncAppender=new AsyncAppender()
		asyncAppender.setBufferSize(bufferSize)
		asyncAppender.addAppender(syncAppender)
		
		//Add the async
		log4jLogger.addAppender(asyncAppender)
		
		//Remove the sync
		log4jLogger.removeAppender(syncAppender)
	}

}