org.apache.maven.plugins.clean.Cleaner Maven / Gradle / Ivy
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The Maven Clean Plugin is a plugin that removes files generated at build-time in a project's directory.
package org.apache.maven.plugins.clean;
/*
* 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.
*/
import java.io.File;
import java.io.IOException;
import org.apache.maven.plugin.logging.Log;
import org.apache.maven.shared.utils.Os;
import org.apache.maven.shared.utils.io.FileUtils;
/**
* Cleans directories.
*
* @author Benjamin Bentmann
*/
class Cleaner
{
private static final boolean ON_WINDOWS = Os.isFamily( Os.FAMILY_WINDOWS );
private final Logger logDebug;
private final Logger logInfo;
private final Logger logVerbose;
private final Logger logWarn;
/**
* Creates a new cleaner.
*
* @param log The logger to use, may be null to disable logging.
* @param verbose Whether to perform verbose logging.
*/
public Cleaner( final Log log, boolean verbose )
{
logDebug = ( log == null || !log.isDebugEnabled() ) ? null : new Logger()
{
public void log( CharSequence message )
{
log.debug( message );
}
};
logInfo = ( log == null || !log.isInfoEnabled() ) ? null : new Logger()
{
public void log( CharSequence message )
{
log.info( message );
}
};
logWarn = ( log == null || !log.isWarnEnabled() ) ? null : new Logger()
{
public void log( CharSequence message )
{
log.warn( message );
}
};
logVerbose = verbose ? logInfo : logDebug;
}
/**
* Deletes the specified directories and its contents.
*
* @param basedir The directory to delete, must not be null. Non-existing directories will be silently
* ignored.
* @param selector The selector used to determine what contents to delete, may be null to delete
* everything.
* @param followSymlinks Whether to follow symlinks.
* @param failOnError Whether to abort with an exception in case a selected file/directory could not be deleted.
* @param retryOnError Whether to undertake additional delete attempts in case the first attempt failed.
* @throws IOException If a file/directory could not be deleted and failOnError is true.
*/
public void delete( File basedir, Selector selector, boolean followSymlinks, boolean failOnError,
boolean retryOnError )
throws IOException
{
if ( !basedir.isDirectory() )
{
if ( !basedir.exists() )
{
if ( logDebug != null )
{
logDebug.log( "Skipping non-existing directory " + basedir );
}
return;
}
throw new IOException( "Invalid base directory " + basedir );
}
if ( logInfo != null )
{
logInfo.log( "Deleting " + basedir + ( selector != null ? " (" + selector + ")" : "" ) );
}
File file = followSymlinks ? basedir : basedir.getCanonicalFile();
delete( file, "", selector, followSymlinks, failOnError, retryOnError );
}
/**
* Deletes the specified file or directory.
*
* @param file The file/directory to delete, must not be null. If followSymlinks is
* false, it is assumed that the parent file is canonical.
* @param pathname The relative pathname of the file, using {@link File#separatorChar}, must not be
* null.
* @param selector The selector used to determine what contents to delete, may be null to delete
* everything.
* @param followSymlinks Whether to follow symlinks.
* @param failOnError Whether to abort with an exception in case a selected file/directory could not be deleted.
* @param retryOnError Whether to undertake additional delete attempts in case the first attempt failed.
* @return The result of the cleaning, never null.
* @throws IOException If a file/directory could not be deleted and failOnError is true.
*/
private Result delete( File file, String pathname, Selector selector, boolean followSymlinks, boolean failOnError,
boolean retryOnError )
throws IOException
{
Result result = new Result();
boolean isDirectory = file.isDirectory();
if ( isDirectory )
{
if ( selector == null || selector.couldHoldSelected( pathname ) )
{
final boolean isSymlink = FileUtils.isSymbolicLink( file );
File canonical = followSymlinks ? file : file.getCanonicalFile();
if ( followSymlinks || !isSymlink )
{
String[] filenames = canonical.list();
if ( filenames != null )
{
String prefix = pathname.length() > 0 ? pathname + File.separatorChar : "";
for ( int i = filenames.length - 1; i >= 0; i-- )
{
String filename = filenames[i];
File child = new File( canonical, filename );
result.update( delete( child, prefix + filename, selector, followSymlinks, failOnError,
retryOnError ) );
}
}
}
else if ( logDebug != null )
{
logDebug.log( "Not recursing into symlink " + file );
}
}
else if ( logDebug != null )
{
logDebug.log( "Not recursing into directory without included files " + file );
}
}
if ( !result.excluded && ( selector == null || selector.isSelected( pathname ) ) )
{
if ( logVerbose != null )
{
if ( isDirectory )
{
logVerbose.log( "Deleting directory " + file );
}
else if ( file.exists() )
{
logVerbose.log( "Deleting file " + file );
}
else
{
logVerbose.log( "Deleting dangling symlink " + file );
}
}
result.failures += delete( file, failOnError, retryOnError );
}
else
{
result.excluded = true;
}
return result;
}
/**
* Deletes the specified file, directory. If the path denotes a symlink, only the link is removed, its target is
* left untouched.
*
* @param file The file/directory to delete, must not be null.
* @param failOnError Whether to abort with an exception in case the file/directory could not be deleted.
* @param retryOnError Whether to undertake additional delete attempts in case the first attempt failed.
* @return 0 if the file was deleted, 1 otherwise.
* @throws IOException If a file/directory could not be deleted and failOnError is true.
*/
private int delete( File file, boolean failOnError, boolean retryOnError )
throws IOException
{
if ( !file.delete() )
{
boolean deleted = false;
if ( retryOnError )
{
if ( ON_WINDOWS )
{
// try to release any locks held by non-closed files
System.gc();
}
final int[] delays = { 50, 250, 750 };
for ( int i = 0; !deleted && i < delays.length; i++ )
{
try
{
Thread.sleep( delays[i] );
}
catch ( InterruptedException e )
{
// ignore
}
deleted = file.delete() || !file.exists();
}
}
else
{
deleted = !file.exists();
}
if ( !deleted )
{
if ( failOnError )
{
throw new IOException( "Failed to delete " + file );
}
else
{
if ( logWarn != null )
{
logWarn.log( "Failed to delete " + file );
}
return 1;
}
}
}
return 0;
}
private static class Result
{
private int failures;
private boolean excluded;
public void update( Result result )
{
failures += result.failures;
excluded |= result.excluded;
}
}
private interface Logger
{
void log( CharSequence message );
}
}