doxia-logging-api/src/main/java/org/apache/maven/doxia/logging/Log.java

package org.apache.maven.doxia.logging;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

/**
 * This interface supplies the API for providing feedback to the user from
 * a Parser or Sink, using standard <code>Doxia</code> channels.
 * <br>
 * There should be no big surprises here, although you may notice that the methods accept
 * <code>java.lang.CharSequence</code> rather than <code>java.lang.String</code>. This is provided mainly as a
 * convenience, to enable developers to pass things like <code>java.lang.StringBuilder</code> directly into the logger,
 * rather than formatting first by calling <code>toString()</code>.
 * <br>
 * Based on <code>org.apache.maven.plugin.logging.Log</code>.
 *
 * @author jdcasey
 * @author ltheussl
 * @version $Id$
 * @since 1.1
 */
public interface Log
{
    /** Typecode for debugging messages. */
    int LEVEL_DEBUG = 0;

    /** Typecode for informational messages. */
    int LEVEL_INFO = 1;

    /** Typecode for warning messages. */
    int LEVEL_WARN = 2;

    /** Typecode for error messages. */
    int LEVEL_ERROR = 3;

    /** Typecode for fatal error messages. */
    int LEVEL_FATAL = 4;

    /** Typecode for disabled log levels. */
    int LEVEL_DISABLED = 5;

    /**
     * Set the current log level.
     *
     * @param level the log level to set.
     */
    void setLogLevel( int level );

    /**
     * <p>isDebugEnabled.</p>
     *
     * @return true if the <b>debug</b> error level is enabled.
     */
    boolean isDebugEnabled();

    /**
     * Send a message to the user in the <b>debug</b> error level.
     *
     * @param content the message to log.
     */
    void debug( CharSequence content );

    /**
     * Send a message (and accompanying exception) to the user in the <b>debug</b> error level.
     * <br>
     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content the message to log.
     * @param error the error to log.
     */
    void debug( CharSequence content, Throwable error );

    /**
     * Send an exception to the user in the <b>debug</b> error level.
     * <br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error the error to log.
     */
    void debug( Throwable error );

    /**
     * <p>isInfoEnabled.</p>
     *
     * @return true if the <b>info</b> error level is enabled.
     */
    boolean isInfoEnabled();

    /**
     * Send a message to the user in the <b>info</b> error level.
     *
     * @param content the message to log.
     */
    void info( CharSequence content );

    /**
     * Send a message (and accompanying exception) to the user in the <b>info</b> error level.
     * <br>
     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content the message to log.
     * @param error the error to log.
     */
    void info( CharSequence content, Throwable error );

    /**
     * Send an exception to the user in the <b>info</b> error level.
     * <br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error the error to log.
     */
    void info( Throwable error );

    /**
     * <p>isWarnEnabled.</p>
     *
     * @return true if the <b>warn</b> error level is enabled.
     */
    boolean isWarnEnabled();

    /**
     * Send a message to the user in the <b>warn</b> error level.
     *
     * @param content the message to log.
     */
    void warn( CharSequence content );

    /**
     * Send a message (and accompanying exception) to the user in the <b>warn</b> error level.
     * <br>
     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content the message to log.
     * @param error the error to log.
     */
    void warn( CharSequence content, Throwable error );

    /**
     * Send an exception to the user in the <b>warn</b> error level.
     * <br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error the error to log.
     */
    void warn( Throwable error );

    /**
     * <p>isErrorEnabled.</p>
     *
     * @return true if the <b>error</b> error level is enabled.
     */
    boolean isErrorEnabled();

    /**
     * Send a message to the user in the <b>error</b> error level.
     *
     * @param content the message to log.
     */
    void error( CharSequence content );

    /**
     * Send a message (and accompanying exception) to the user in the <b>error</b> error level.
     * <br>
     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content the message to log.
     * @param error the error to log.
     */
    void error( CharSequence content, Throwable error );

    /**
     * Send an exception to the user in the <b>error</b> error level.
     * <br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error the error to log.
     */
    void error( Throwable error );
}