org.apache.mina.util.Log4jXmlFormatter Maven / Gradle / Ivy

/**
 * Copyright 2007-2015, Kaazing Corporation. All rights reserved.
 *
 * 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.apache.mina.util;

import org.slf4j.MDC;
import org.slf4j.helpers.BasicMDCAdapter;

import java.util.logging.Formatter;
import java.util.logging.LogRecord;
import java.util.Set;
import java.util.Arrays;

/**
 * Implementation of {@link java.util.logging.Formatter} that generates xml in the log4j format.
 * 
 * The generated xml corresponds 100% with what is generated by
 * log4j's XMLLayout
 * 

 * The MDC properties will only be correct when format is called from the same thread
 * that generated the LogRecord.
 * 

 * The file and line attributes in the locationInfo element will always be "?"
 * since java.util.logging.LogRecord does not provide that info.
 * 

 * The implementation is heavily based on org.apache.log4j.xml.XMLLayout
 * 
 * 
 * @author Apache MINA Project
 */
public class Log4jXmlFormatter extends Formatter {

    private final int DEFAULT_SIZE = 256;
    private final int UPPER_LIMIT = 2048;

    private StringBuffer buf = new StringBuffer(DEFAULT_SIZE);
    private boolean locationInfo = false;
    private boolean properties = false;

    /**
     * The LocationInfo option takes a boolean value. By default,
     * it is set to false which means there will be no location
     * information output by this layout. If the the option is set to
     * true, then the file name and line number of the statement at the
     * origin of the log statement will be output.
     *
     * @param flag whether locationInfo should be output by this layout
     */
    public void setLocationInfo(boolean flag) {
        locationInfo = flag;
    }

    /**
     * Returns the current value of the LocationInfo option.
     *
     * @return whether locationInfo will be output by this layout
     */
    public boolean getLocationInfo() {
        return locationInfo;
    }

    /**
     * Sets whether MDC key-value pairs should be output, default false.
     *
     * @param flag new value.
     */
    public void setProperties(final boolean flag) {
        properties = flag;
    }

    /**
     * Gets whether MDC key-value pairs should be output.
     *
     * @return true if MDC key-value pairs are output.
     */
    public boolean getProperties() {
        return properties;
    }

    @SuppressWarnings("unchecked")
    public String format(final LogRecord record) {
        // Reset working buffer. If the buffer is too large, then we need a new
        // one in order to avoid the penalty of creating a large array.
        if (buf.capacity() > UPPER_LIMIT) {
            buf = new StringBuffer(DEFAULT_SIZE);
        } else {
            buf.setLength(0);
        }
        buf.append("\r\n");

        buf.append("\r\n");

        if (record.getThrown() != null) {
            String[] s = Transform.getThrowableStrRep(record.getThrown());
            if (s != null) {
                buf.append("\r\n");
            }
        }

        if (locationInfo) {
            buf.append("\r\n");
        }

        if (properties) {
            if (MDC.getMDCAdapter() instanceof BasicMDCAdapter) {
                BasicMDCAdapter mdcAdapter = (BasicMDCAdapter) MDC.getMDCAdapter();
                Set keySet = mdcAdapter.getKeys();
                if (keySet != null && keySet.size() > 0) {
                    buf.append("\r\n");
                    Object[] keys = keySet.toArray();
                    Arrays.sort(keys);
                    for (Object key1 : keys) {
                        String key = key1.toString();
                        Object val = mdcAdapter.get(key);
                        if (val != null) {
                            buf.append("\r\n");
                        }
                    }
                    buf.append("\r\n");
                }
            }
        }
        buf.append("\r\n\r\n");

        return buf.toString();
    }

}