JmxLogConfigurer.java

package com.services.util;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

import org.apache.log4j.Level;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.apache.log4j.config.PropertyPrinter;
import org.slf4j.LoggerFactory;
import org.springframework.jmx.export.annotation.ManagedOperation;
import org.springframework.jmx.export.annotation.ManagedResource;
import org.springframework.stereotype.Component;

/**
 * JMX log configurer
 * Created by golonzovsky
 */
@Component
@ManagedResource(objectName = "com.config:type=core,name=LogConfigurer")
public class JmxLogConfigurer {

  private static final org.slf4j.Logger LOG = LoggerFactory.getLogger(JmxLogConfigurer.class);

  @ManagedOperation
  public String[] getLoggers() {
    Enumeration<Logger> loggers = LogManager.getLoggerRepository().getCurrentLoggers();
    List<String> loggersInfo = new ArrayList<String>();

    while (loggers.hasMoreElements()) {
      Logger logger = loggers.nextElement();
      loggersInfo.add(logger.getName());
    }

    return loggersInfo.toArray(new String[loggersInfo.size()]);
  }

  @ManagedOperation
  public void assignInfoLevel(String target) {
    assignLogLevel(target, Level.INFO);
  }

  @ManagedOperation
  public void assignWarnLevel(String target) {
    assignLogLevel(target, Level.WARN);
  }

  @ManagedOperation
  public void assignErrorLevel(String target) {
    assignLogLevel(target, Level.ERROR);
  }

  @ManagedOperation
  public void assignDebugLevel(String target) {
    assignLogLevel(target, Level.DEBUG);
  }

  @ManagedOperation
  public void assignFatalLevel(String target) {
    assignLogLevel(target, Level.FATAL);
  }

  @ManagedOperation
  public void deactivateLogging(String target) {
    assignLogLevel(target, Level.OFF);
  }

  @ManagedOperation
  public void assignTraceLevel(String target) {
    assignLogLevel(target, Level.TRACE);
  }

  private void assignLogLevel(String loggingTarget, Level level) {
    LOG.info("changing log level for '{}' from '{}' to '{}'",
        new Object[]{level.toString(), getExistingLevel(loggingTarget), loggingTarget});
    LogManager.getLogger(loggingTarget).setLevel(level);
  }

  private String getExistingLevel(String target) {
    Logger existingLogger = LogManager.exists(target);
    if (existingLogger == null || existingLogger.getLevel() == null) {
      return null;
    }
    return existingLogger.getLevel().toString();
  }

  @ManagedOperation
  public String printLog4jConfig() {
    StringWriter sw = new StringWriter();
    PrintWriter pw = new PrintWriter(sw);
    PropertyPrinter pp = new PropertyPrinter(pw);
    pp.print(pw);
    return sw.toString();
  }
}