org.codehaus.mojo.apt.LogUtils.java Source code

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Here is the source code for org.codehaus.mojo.apt.LogUtils.java

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package org.codehaus.mojo.apt;

/*
 * The MIT License
 *
 * Copyright 2006-2008 The Codehaus.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.util.Collection;

import org.apache.maven.plugin.logging.Log;
import org.codehaus.plexus.util.IOUtil;

/**
 * Provides utilities for working with Mojo logs.
 * 
 * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
 * @version $Id$
 */
public final class LogUtils {
    // constants --------------------------------------------------------------

    public static final int LEVEL_DEBUG = 0;

    public static final int LEVEL_INFO = 1;

    public static final int LEVEL_WARN = 2;

    public static final int LEVEL_ERROR = 3;

    // constructors -----------------------------------------------------------

    private LogUtils() {
        throw new AssertionError();
    }

    // public methods ---------------------------------------------------------

    public static void log(Log log, int level, File file) {
        log(log, level, file, null);
    }

    public static void log(Log log, int level, File file, CharSequence prefix) {
        if (!isEnabled(log, level)) {
            return;
        }

        FileReader reader = null;

        try {
            reader = new FileReader(file);

            log(log, level, reader, prefix);
        } catch (FileNotFoundException exception) {
            log.warn("Error logging file", exception);
        } finally {
            IOUtil.close(reader);
        }
    }

    public static void log(Log log, int level, Reader reader) {
        log(log, level, reader, null);
    }

    public static void log(Log log, int level, Reader reader, CharSequence prefix) {
        if (!isEnabled(log, level)) {
            return;
        }

        BufferedReader bufferedReader = new BufferedReader(reader);

        String line;

        try {
            while ((line = bufferedReader.readLine()) != null) {
                log(log, level, line, prefix);
            }
        } catch (IOException exception) {
            log.warn("Error logging reader", exception);
        }
    }

    public static void log(Log log, int level, Collection<?> messages) {
        log(log, level, messages, null);
    }

    public static void log(Log log, int level, Collection<?> messages, CharSequence prefix) {
        if (!isEnabled(log, level)) {
            return;
        }

        for (Object message : messages) {
            log(log, level, message, prefix);
        }
    }

    public static void log(Log log, int level, Object message) {
        log(log, level, message, null);
    }

    public static void log(Log log, int level, Object message, CharSequence prefix) {
        CharSequence chars;

        if (message instanceof CharSequence) {
            chars = (CharSequence) message;
        } else {
            chars = String.valueOf(message);
        }

        log(log, level, chars, prefix);
    }

    public static void log(Log log, int level, CharSequence message) {
        if (level == LEVEL_DEBUG) {
            log.debug(message);
        } else if (level == LEVEL_INFO) {
            log.info(message);
        } else if (level == LEVEL_WARN) {
            log.warn(message);
        } else if (level == LEVEL_ERROR) {
            log.error(message);
        } else {
            throw new IllegalArgumentException("Unknown log level: " + level);
        }
    }

    public static void log(Log log, int level, CharSequence message, CharSequence prefix) {
        log(log, level, format(message, prefix));
    }

    public static boolean isEnabled(Log log, int level) {
        boolean enabled;

        if (level == LEVEL_DEBUG) {
            enabled = log.isDebugEnabled();
        } else if (level == LEVEL_INFO) {
            enabled = log.isInfoEnabled();
        } else if (level == LEVEL_WARN) {
            enabled = log.isWarnEnabled();
        } else if (level == LEVEL_ERROR) {
            enabled = log.isErrorEnabled();
        } else {
            throw new IllegalArgumentException("Unknown log level: " + level);
        }

        return enabled;
    }

    // private methods --------------------------------------------------------

    private static CharSequence format(CharSequence message, CharSequence prefix) {
        if (prefix == null || prefix.length() == 0) {
            return message;
        }

        return new StringBuffer(prefix).append(message).toString();
    }
}