org.openmrs.module.logmanager.impl.ManagerProxy.java Source code

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Here is the source code for org.openmrs.module.logmanager.impl.ManagerProxy.java

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/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.module.logmanager.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.log4j.Appender;
import org.apache.log4j.Level;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

/**
 * Proxy class for LogManager methods
 */
public class ManagerProxy {

    protected static final Log log = LogFactory.getLog(ManagerProxy.class);

    /**
     * Gets the appender with the specified id
     * @param id the appender id
     * @return the appender
     */
    public static AppenderProxy getAppender(int id) {
        Collection<AppenderProxy> appenders = getAppenders();
        for (AppenderProxy appender : appenders)
            if (appender.getId() == id)
                return appender;
        return null;
    }

    /**
     * Gets all the appenders currently attached to a logger
     * @return the set of appenders
     */
    @SuppressWarnings("unchecked")
    public static Set<AppenderProxy> getAppenders() {
        Set<AppenderProxy> appenders = new HashSet<AppenderProxy>();

        // Add system appender
        if (AppenderProxy.getSystemAppender() != null)
            appenders.add(AppenderProxy.getSystemAppender());

        // Add appenders attached to the root logger
        Enumeration<Appender> rootAppenders = LogManager.getRootLogger().getAllAppenders();
        while (rootAppenders.hasMoreElements())
            appenders.add(new AppenderProxy(rootAppenders.nextElement()));

        // Search for appenders on all other loggers
        Enumeration<Logger> loggersEnum = LogManager.getCurrentLoggers();
        while (loggersEnum.hasMoreElements()) {
            Logger logger = loggersEnum.nextElement();
            Enumeration<Appender> appendersEnum = logger.getAllAppenders();

            while (appendersEnum.hasMoreElements())
                appenders.add(new AppenderProxy(appendersEnum.nextElement()));
        }

        return appenders;
    }

    /**
     * Gets all loggers currently being used
     * @param incImplicit true to include loggers with inherited levels and appenders
     * @return the list of loggers
     */
    @SuppressWarnings("unchecked")
    public static List<LoggerProxy> getLoggers(boolean incImplicit) {
        Enumeration<Logger> loggersEnum = (Enumeration<Logger>) LogManager.getCurrentLoggers();

        // Convert enum to a list
        List<Logger> loggers = incImplicit ? Collections.list(loggersEnum)
                : getExplicitLoggersFromEnum(loggersEnum);

        // Sort list by logger name
        Collections.sort(loggers, new Comparator<Logger>() {
            public int compare(Logger log1, Logger log2) {
                return log1.getName().compareTo(log2.getName());
            }
        });

        // Convert to proxy objects
        List<LoggerProxy> proxies = new ArrayList<LoggerProxy>();
        for (Logger logger : loggers)
            proxies.add(new LoggerProxy(logger));

        return proxies;
    }

    /**
     * Gets all loggers with matching name prefix
     * @param prefix the name prefix
     * @param limit the maximum number of loggers to return
     * @return the list of loggers
     */
    @SuppressWarnings("unchecked")
    public static List<LoggerProxy> getLoggers(String prefix, int limit) {
        Enumeration<Logger> loggersEnum = (Enumeration<Logger>) LogManager.getCurrentLoggers();
        List<Logger> loggers = new ArrayList<Logger>();

        // Filter based on logger name and max count
        if (prefix != null) {
            while (loggersEnum.hasMoreElements()) {
                Logger logger = loggersEnum.nextElement();
                if (logger.getName().startsWith(prefix)) {
                    loggers.add(logger);

                }
            }
        }

        // Sort list by logger name
        Collections.sort(loggers, new Comparator<Logger>() {
            public int compare(Logger log1, Logger log2) {
                return log1.getName().compareTo(log2.getName());
            }
        });

        // Convert first N loggers to proxy objects
        List<LoggerProxy> proxies = new ArrayList<LoggerProxy>();
        int count = 0;
        for (Logger logger : loggers) {
            proxies.add(new LoggerProxy(logger));
            if (++count >= limit)
                break;
        }

        return proxies;
    }

    /**
     * Gets the root logger
     * @return the root logger
     */
    public static LoggerProxy getRootLogger() {
        return new LoggerProxy(LogManager.getRootLogger());
    }

    /**
     * Gets the specified logger
     * @param name the logger name
     * @param force forces logger creation if it doesn't exist
     * @return the logger or null if logger doesn't exist
     */
    public static LoggerProxy getLogger(String name, boolean force) {
        if (force)
            return new LoggerProxy(LogManager.getLogger(name));

        Logger target = LogManager.exists(name);
        return (target != null) ? new LoggerProxy(target) : null;
    }

    /**
     * Logs an event in the logging system
     * @param loggerName the name of the logger
     * @param level the event level
     * @param message the event message
     */
    public static void logEvent(String loggerName, LevelProxy level, String message) {
        LoggerProxy logger = getLogger(loggerName, true);
        logger.log(Level.toLevel(level.getIntValue()), message);
    }

    /**
     * Gets all loggers with explicit level or appenders from an enumeration of loggers
     * @param loggersEnum the enumeration of loggers
     * @return the list of loggers
     */
    private static List<Logger> getExplicitLoggersFromEnum(Enumeration<Logger> loggersEnum) {
        List<Logger> loggers = new ArrayList<Logger>();

        while (loggersEnum.hasMoreElements()) {
            Logger logger = loggersEnum.nextElement();
            if (logger.getLevel() != null || logger.getAllAppenders().hasMoreElements())
                loggers.add(logger);
        }

        return loggers;
    }
}