org.modelibra.util.Log4jConfigurator.java Source code

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Here is the source code for org.modelibra.util.Log4jConfigurator.java

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/*
 * Modelibra
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.modelibra.util;

import java.io.File;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.log4j.xml.DOMConfigurator;

/**
 * Log4j initialization. The file path to the log4j XML configuration is found
 * and the log4j software is configured. Two problems: (1) relative path does
 * not work properly in Tomcat; (2) error messages go to info.html and not to
 * error.html.
 * 
 * @version 2007-01-30
 * @author Dzenan Ridjanovic
 */
public class Log4jConfigurator {

    public static final String CLASS_DIRECTORY = "classes";

    public static final String CONFIG_DIRECTORY = "config";

    private String log4jPath;

    /**
     * Constructs the log4j configurator. Finds the log4j configuration file
     * path.
     */
    public Log4jConfigurator() {
        this(CLASS_DIRECTORY, CONFIG_DIRECTORY);
    }

    /**
     * Constructs the log4j configurator. Finds the log4j configuration file
     * path.
     * 
     * @param classDirName
     *            classes directory name
     * @param configDirName
     *            configuration directory name
     */
    public Log4jConfigurator(String classDirName, String configDirName) {
        log4jPath = findConfigFilePath(classDirName, configDirName);
    }

    /**
     * Sets the log4j configuration file path.
     * 
     * @param configFilePath
     *            configuration file path
     */
    public Log4jConfigurator(String configFilePath) {
        log4jPath = configFilePath;
    }

    /**
     * Configures log4j.
     */
    public void configure() {
        if (log4jPath != null) {
            configureLog4j(log4jPath);
        }
    }

    /**
     * Configures log4j.
     * 
     * @param configFilePath
     *            configuration file path
     */
    private void configureLog4j(String configFilePath) {
        DOMConfigurator.configure(configFilePath);
    }

    /**
     * Finds a path to the log4j config XML file.
     * 
     * @param classDirName
     *            classes directory name
     * @param configDirName
     *            configuration directory name
     * @return path to the log4j config XML file
     */
    private String findConfigFilePath(String classDirName, String configDirName) {
        PathLocator fileLocator = new PathLocator();
        String log4jPath = fileLocator.findAbsolutePath(Log4jConfigurator.class, classDirName,
                configDirName + File.separator + "log4j.xml");
        return log4jPath;
    }

    public static void main(String[] args) {
        Log4jConfigurator log4jConfigurator = new Log4jConfigurator();
        log4jConfigurator.configure();

        Log log = LogFactory.getLog(Log4jConfigurator.class);
        log.info("Check if log4j works for info.");

        // Goes to info.html and not to error.html!?
        log.error("Check if log4j works for error.");

    }

}