/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.core.util;

 import org.apache.log4j.Logger;

 import static org.apache.log4j.Level.WARN;

 import static org.apache.log4j.Level.ERROR;

 import static org.apache.log4j.Level.FATAL;

 /**

  * Class with static methods wrapping {@link Logger} methods. Automatically sets up logger for you. It's called the <code>BufferedLogger</code> because

  * it handles everything in a {@link StringBuilder} using {@link StringBuilder#append(CharSequence)} method<br/>

  * <br/>

  *  

  * To use these just do

  * <code>

  * import BufferedLogger.*

  * </code>

  * 

  * @see org.apache.log4j.Logger

  */

 public class BufferedLogger {

     /**

      * Applies a pattern with parameters to create a {@link String} used as a logging message

      *  

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      * @return Logging Message

      */

     private static final CharSequence getMessage(Object ... objs) {

         StringBuilder retval = new StringBuilder();

         for (Object obj : objs) {

             retval.append(obj);

         }

         return retval;

     }

     /**

      * Uses {@link StackTraceElement[]} from {@link Throwable} to determine the calling class. Then, the {@link Logger} is retrieved for it by

      * convention

      * 

      * 

      * @return Logger for the calling class

      */

     private static final Logger getLogger() {

         try {

             return Logger.getLogger(Class.forName(new Throwable().getStackTrace()[2].getClassName()));

         }

         catch (Exception e) {

             // This will never happen unless Java is broken

             return Logger.getLogger(BufferedLogger.class);

         }

     }

     /**

      * Uses {@link StackTraceElement[]} from {@link Throwable} to determine the calling class. Then, the {@link Logger} is retrieved for it by

      * convention. Just like {@link #getLogger()} except this is intended to be called directly from classes.

      * 

      * 

      * @return Logger for the calling class

      */

     public static final Logger logger() {

         try {

             return Logger.getLogger(Class.forName(new Throwable().getStackTrace()[1].getClassName()));

         }

         catch (Exception e) {

             // This will never happen unless Java is broken

             return Logger.getLogger(BufferedLogger.class);

         }

     }

     /**

      * Wraps {@link Logger#trace(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void trace(Object ... objs) {

         Logger log = getLogger();

         if (log.isTraceEnabled()) {

             log.trace(getMessage(objs));

         }

     }

     /**

      * Wraps {@link Logger#debug(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void debug(Object ... objs) {

         Logger log = getLogger();

         if (log.isDebugEnabled()) {

             log.debug(getMessage(objs));

         }

     }

     /**

      * Wraps {@link Logger#info(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void info(Object ... objs) {

         Logger log = getLogger();

         if (log.isInfoEnabled()) {

             log.info(getMessage(objs));

         }

     }

     /**

      * Wraps {@link Logger#warn(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void warn(Object ... objs) {

         Logger log = getLogger();

         if (log.isEnabledFor(WARN)) {

             log.warn(getMessage(objs));

         }

     }

     /**

      * Wraps {@link Logger#error(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void error(Object ... objs) {

         Logger log = getLogger();

         if (log.isEnabledFor(ERROR)) {

             getLogger().error(getMessage(objs));

         }

     }

     /**

      * Wraps {@link Logger#fatal(String)}

      * 

      * @param pattern to format against

      * @param objs an array of objects used as parameters to the <code>pattern</code>

      */

     public static final void fatal(Object ... objs) {

         Logger log = getLogger();

         if (log.isEnabledFor(FATAL)) {

             log.fatal(getMessage(objs));

         }

     }

 }