TraceMBean.java

package org.springside.examples.showcase.log.trace;

import java.util.Enumeration;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.springframework.jmx.export.annotation.ManagedAttribute;
import org.springframework.jmx.export.annotation.ManagedOperation;
import org.springframework.jmx.export.annotation.ManagedResource;

/**
 * 控制是否输出DEBUG信息到Trace Appender的MBean, 可用JMX或JSP调用.
 *
 * @author jeff zhu
 */
@ManagedResource(objectName = TraceMBean.TRACE_MBEAN_NAME, description = "Trace Management Bean")
public class TraceMBean {

	/**
	 * TraceMbean的注册名称.
	 */
	public static final String TRACE_MBEAN_NAME = "Showcase:name=trace,type=Trace";

	private String traceLoggerName = "org.springside.examples.showcase";

	@ManagedAttribute(description = "Check if the trace is open or not")
	public boolean getTraceStatus() {
		Logger logger = Logger.getLogger(traceLoggerName);
		Level level = logger.getEffectiveLevel();
		return level.getSyslogEquivalent() >= Level.DEBUG.getSyslogEquivalent();
	}

	@ManagedOperation(description = "Start trace")
	public void startTrace() {
		Logger logger = Logger.getLogger(traceLoggerName);
		logger.setLevel(Level.DEBUG);
		setLoggerAppendersLevel(logger, Level.DEBUG);
	}

	@ManagedOperation(description = "Stop trace")
	public void stopTrace() {
		Logger logger = Logger.getLogger(traceLoggerName);
		logger.setLevel(Level.INFO);
		setLoggerAppendersLevel(logger, Level.OFF);
	}

	@SuppressWarnings("unchecked")
	private void setLoggerAppendersLevel(Logger logger, Level level) {
		Enumeration e = logger.getAllAppenders();
		while (e.hasMoreElements()) {
			AppenderSkeleton appender = (AppenderSkeleton) e.nextElement();
			appender.setThreshold(level);
		}
	}

	public void setTraceLoggerName(String traceLoggerName) {
		this.traceLoggerName = traceLoggerName;
	}
}