org.apache.commons.io.filefilter

Class PrefixFileFilter

java.lang.Object

org.apache.commons.io.filefilter.AbstractFileFilter

org.apache.commons.io.filefilter.PrefixFileFilter

All Implemented Interfaces:

FileFilter, FilenameFilter, Serializable, FileVisitor<Path>, PathFilter, PathVisitor, IOFileFilter

public class PrefixFileFilter
extends AbstractFileFilter
implements Serializable

Filters file names for a certain prefix.

For example, to print all files and directories in the current directory whose name starts with Test:

Using Classic IO

 File dir = new File(".");
 String[] files = dir.list(new PrefixFileFilter("Test"));
 for (String file : files) {
     System.out.println(file);
 }
 

Using NIO

 final Path dir = Paths.get("");
 final AccumulatorPathVisitor visitor = AccumulatorPathVisitor.withLongCounters(new PrefixFileFilter("Test"));
 //
 // Walk one dir
 Files.walkFileTree(dir, Collections.emptySet(), 1, visitor);
 System.out.println(visitor.getPathCounters());
 System.out.println(visitor.getFileList());
 //
 visitor.getPathCounters().reset();
 //
 // Walk dir tree
 Files.walkFileTree(dir, visitor);
 System.out.println(visitor.getPathCounters());
 System.out.println(visitor.getDirList());
 System.out.println(visitor.getFileList());
 

Since:

1.0

See Also:

FileFilterUtils.prefixFileFilter(String), FileFilterUtils.prefixFileFilter(String, IOCase), Serialized Form

Field Summary

Fields inherited from interface org.apache.commons.io.filefilter.IOFileFilter

EMPTY_STRING_ARRAY

Constructor Summary

Constructors

Constructor and Description
PrefixFileFilter(List<String> prefixes) Constructs a new Prefix file filter for a list of prefixes.
PrefixFileFilter(List<String> prefixes, IOCase caseSensitivity) Constructs a new Prefix file filter for a list of prefixes specifying case-sensitivity.
PrefixFileFilter(String... prefixes) Constructs a new Prefix file filter for any of an array of prefixes.
PrefixFileFilter(String prefix) Constructs a new Prefix file filter for a single prefix.
PrefixFileFilter(String[] prefixes, IOCase caseSensitivity) Constructs a new Prefix file filter for any of an array of prefixes specifying case-sensitivity.
PrefixFileFilter(String prefix, IOCase caseSensitivity) Constructs a new Prefix file filter for a single prefix specifying case-sensitivity.

Method Summary

Modifier and Type	Method and Description
boolean	accept(File file) Checks to see if the file name starts with the prefix.
boolean	accept(File file, String name) Checks to see if the file name starts with the prefix.
FileVisitResult	accept(Path file, BasicFileAttributes attributes) Checks to see if the file name starts with the prefix.
String	toString() Provide a String representation of this file filter.

Methods inherited from class org.apache.commons.io.filefilter.AbstractFileFilter

handle, postVisitDirectory, preVisitDirectory, visitFile, visitFileFailed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.commons.io.filefilter.IOFileFilter

and, negate, or

Constructor Detail

PrefixFileFilter

public PrefixFileFilter(List<String> prefixes)

Constructs a new Prefix file filter for a list of prefixes.

Parameters:

prefixes - the prefixes to allow, must not be null

Throws:

IllegalArgumentException - if the prefix list is null

ClassCastException - if the list does not contain Strings

PrefixFileFilter

public PrefixFileFilter(List<String> prefixes,
                        IOCase caseSensitivity)

Constructs a new Prefix file filter for a list of prefixes specifying case-sensitivity.

Parameters:

prefixes - the prefixes to allow, must not be null

caseSensitivity - how to handle case sensitivity, null means case-sensitive

Throws:

IllegalArgumentException - if the prefix list is null

ClassCastException - if the list does not contain Strings

Since:

1.4

PrefixFileFilter

public PrefixFileFilter(String prefix)

Constructs a new Prefix file filter for a single prefix.

Parameters:

prefix - the prefix to allow, must not be null

Throws:

IllegalArgumentException - if the prefix is null

PrefixFileFilter

public PrefixFileFilter(String... prefixes)

Constructs a new Prefix file filter for any of an array of prefixes.

The array is not cloned, so could be changed after constructing the instance. This would be inadvisable however.

Parameters:

prefixes - the prefixes to allow, must not be null

Throws:

IllegalArgumentException - if the prefix array is null

PrefixFileFilter

public PrefixFileFilter(String prefix,
                        IOCase caseSensitivity)

Constructs a new Prefix file filter for a single prefix specifying case-sensitivity.

Parameters:

prefix - the prefix to allow, must not be null

caseSensitivity - how to handle case sensitivity, null means case-sensitive

Throws:

IllegalArgumentException - if the prefix is null

Since:

1.4

PrefixFileFilter

public PrefixFileFilter(String[] prefixes,
                        IOCase caseSensitivity)

Constructs a new Prefix file filter for any of an array of prefixes specifying case-sensitivity.

Parameters:

prefixes - the prefixes to allow, must not be null

caseSensitivity - how to handle case sensitivity, null means case-sensitive

Throws:

IllegalArgumentException - if the prefix is null

Since:

1.4

Method Detail

accept

public boolean accept(File file)

Checks to see if the file name starts with the prefix.

Specified by:

accept in interface FileFilter

Specified by:

accept in interface IOFileFilter

Overrides:

accept in class AbstractFileFilter

Parameters:

file - the File to check

Returns:

true if the file name starts with one of our prefixes

accept

public boolean accept(File file,
                      String name)

Checks to see if the file name starts with the prefix.

Specified by:

accept in interface FilenameFilter

Specified by:

accept in interface IOFileFilter

Overrides:

accept in class AbstractFileFilter

Parameters:

file - the File directory

name - the file name

Returns:

true if the file name starts with one of our prefixes

accept

public FileVisitResult accept(Path file,
                              BasicFileAttributes attributes)

Checks to see if the file name starts with the prefix.

Specified by:

accept in interface PathFilter

Specified by:

accept in interface IOFileFilter

Parameters:

file - the File to check

attributes - the file's basic attributes (TODO may be null).

Returns:

true if the file name starts with one of our prefixes

Since:

2.9.0

toString

public String toString()

Provide a String representation of this file filter.

Overrides:

toString in class AbstractFileFilter

Returns:

a String representation