Splits apart a OS separator delimited set of paths in a string into multiple Strings.
import java.io.File;
import java.io.FileFilter;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
/*
* 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.
*
*/
/**
* Various string manipulation methods that are more efficient then chaining
* string operations: all is done in the same buffer without creating a bunch of
* string objects.
*
* @author <a href="mailto:dev@labs.apache.org">Dungeon Project</a>
*/
public class Main {
/**
* Splits apart a OS separator delimited set of paths in a string into
* multiple Strings. File component path strings are returned within a List
* in the order they are found in the composite path string. Optionally, a
* file filter can be used to filter out path strings to control the
* components returned. If the filter is null all path components are
* returned.
*
* @param paths
* a set of paths delimited using the OS path separator
* @param filter
* a FileFilter used to filter the return set
* @return the filter accepted path component Strings in the order
* encountered
*/
public static final List getPaths( String paths, FileFilter filter )
{
int start = 0;
int stop = -1;
String path = null;
ArrayList<String> list = new ArrayList<String>();
// Abandon with no values if paths string is null
if ( paths == null || paths.trim().equals( "" ) )
{
return list;
}
final int max = paths.length() - 1;
// Loop spliting string using OS path separator: terminate
// when the start index is at the end of the paths string.
while ( start < max )
{
stop = paths.indexOf( File.pathSeparatorChar, start );
// The is no file sep between the start and the end of the string
if ( stop == -1 )
{
// If we have a trailing path remaining without ending separator
if ( start < max )
{
// Last path is everything from start to the string's end
path = paths.substring( start );
// Protect against consecutive separators side by side
if ( !path.trim().equals( "" ) )
{
// If filter is null add path, if it is not null add the
// path only if the filter accepts the path component.
if ( filter == null || filter.accept( new File( path ) ) )
{
list.add( path );
}
}
}
break; // Exit loop no more path components left!
}
// There is a separator between start and the end if we got here!
// start index is now at 0 or the index of last separator + 1
// stop index is now at next separator in front of start index
path = paths.substring( start, stop );
// Protect against consecutive separators side by side
if ( !path.trim().equals( "" ) )
{
// If filter is null add path, if it is not null add the path
// only if the filter accepts the path component.
if ( filter == null || filter.accept( new File( path ) ) )
{
list.add( path );
}
}
// Advance start index past separator to start of next path comp
start = stop + 1;
}
return list;
}
}
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