org.das2.util

Class FileUtil

java.lang.Object

org.das2.util.FileUtil

public class FileUtil
extends java.lang.Object

static utility methods. introduced Jul 28, 2008.

Method Summary

Modifier and Type	Method and Description
static int	consumeStream(java.io.InputStream in) read all the bytes off the stream, perhaps to empty a URL response.
static boolean	deleteFileTree(java.io.File root) deletes all files and folders below root, and root, just as "rm -r" would.
static boolean	deleteFileTree(java.io.File root, java.util.Set<java.lang.String> exclude) deletes all files and folders below root, and root, just as "rm -r" would, excluding any files named in exclude.
static boolean	deleteWithinFileTree(java.io.File root, java.lang.String name) deletes all files with the given name, and root, just as "find .
static boolean	fileCompare(java.io.File file1, java.io.File file2) returns True if the file contents are equal.
static void	fileCopy(java.io.File src, java.io.File dst) copies the file or folder from src to dst.
static java.io.File	find(java.io.File[] roots, java.lang.String name) find a files with the given name within one of the given roots.
static int	find(java.io.File root, java.util.regex.Pattern pattern, java.util.List<java.lang.String> result) find a files with the given pattern within the given root, just as "find .
static java.io.File	find(java.io.File root, java.lang.String name) find a files with the given name within the given root, just as "find .
static java.lang.String	getMagic(java.io.File src) return the first four bytes of the file as a string.
static boolean	isParent(java.io.File possibleParent, java.io.File maybeChild) return true of the maybeChild parent is a child of possibleParent.
static int	lineCount(java.io.File f) return the number of lines in the text file.
static java.util.List<java.io.File>	listRecursively(java.io.File root, java.util.regex.Pattern name, java.util.List<java.io.File> matches) find all files under the root matching the spec.
static java.io.File[]	listRecursively(java.io.File root, java.lang.String glob) Return an array of files where the regex is found at the end.
static java.lang.String	readFileToString(java.io.File f) read all the bytes in the UTF-8 encoded file into a string.
static java.lang.String	readInputStreamToString(java.io.InputStream ins) read all the bytes in the UTF-8 encoded inputStream into a string.
static void	writeStringToFile(java.io.File f, java.lang.String src) write all the bytes in the string to a file using UTF-8 encoding.

Methods inherited from class java.lang.Object

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

Method Detail

fileCompare

public static boolean fileCompare(java.io.File file1,
                                  java.io.File file2)

returns True if the file contents are equal.

Parameters:

file1 -

file2 -

Returns:

true if the two files have identical

isParent

public static boolean isParent(java.io.File possibleParent,
                               java.io.File maybeChild)

return true of the maybeChild parent is a child of possibleParent. Note either can be null, and this will not throw an exception, but will return false.

Parameters:

possibleParent - parent file.

maybeChild - a file or folder which may exist within possibleParent.

Returns:

true if the possibleParent is actually a parent of maybeChild.

deleteFileTree

public static boolean deleteFileTree(java.io.File root)
                              throws java.lang.IllegalArgumentException

deletes all files and folders below root, and root, just as "rm -r" would. TODO: check links

Parameters:

root - the root where we start deleting.

Returns:

true if the operation was successful.

Throws:

java.lang.IllegalArgumentException - if it is unable to delete a file

deleteFileTree

public static boolean deleteFileTree(java.io.File root,
                                     java.util.Set<java.lang.String> exclude)
                              throws java.lang.IllegalArgumentException

deletes all files and folders below root, and root, just as "rm -r" would, excluding any files named in exclude. For example, exclude could contain "readme.txt".

Parameters:

root - the root where we start deleting.

exclude - null or a set containing names to exclude.

Returns:

true if the operation was successful.

Throws:

java.lang.IllegalArgumentException - if it is unable to delete a file

deleteWithinFileTree

public static boolean deleteWithinFileTree(java.io.File root,
                                           java.lang.String name)
                                    throws java.lang.IllegalArgumentException

deletes all files with the given name, and root, just as "find . -name name -exec rm {} \;" would. TODO: check links. For example deleteWithinFileTree( root, ".listing" )

Parameters:

root - the root directory of the tree.

name - the file name.

Returns:

true if the operation was successful.

Throws:

java.lang.IllegalArgumentException - if it is unable to delete a file

find

public static java.io.File find(java.io.File root,
                                java.lang.String name)
                         throws java.lang.IllegalArgumentException

find a files with the given name within the given root, just as "find . -name name -print \;" would. TODO: check links. For example, find( "/usr/share/fonts/truetype", "FreeMono.ttf" )

Parameters:

root - the root to start

name - name to look for.

Returns:

the File found, or null if it does not exist.

Throws:

java.lang.IllegalArgumentException - if the root does not exist.

find

public static int find(java.io.File root,
                       java.util.regex.Pattern pattern,
                       java.util.List<java.lang.String> result)
                throws java.lang.IllegalArgumentException

find a files with the given pattern within the given root, just as "find . -name *.dat -print \;" would. TODO: check links. For example, find( "/usr/share/fonts/truetype", "FreeMono.ttf" )

Parameters:

root - the root to start

pattern - name to look for.

result - results are added to this list, or null if the count that is all that is needed.

Returns:

the number of files found

Throws:

java.lang.IllegalArgumentException - if the root does not exist.

See Also:

Glob

find

public static java.io.File find(java.io.File[] roots,
                                java.lang.String name)

find a files with the given name within one of the given roots. TODO: check links. For example, find( "/usr/share/fonts/truetype", "FreeMono.ttf" ) This allows root folders that do not exist.

Parameters:

roots - array of roots to start search.

name - name to look for.

Returns:

the File found, or null if it does not exist.

listRecursively

public static java.util.List<java.io.File> listRecursively(java.io.File root,
                                                           java.util.regex.Pattern name,
                                                           java.util.List<java.io.File> matches)

find all files under the root matching the spec.

Parameters:

root - the root of the search (e.g. /fonts/)

name - the pattern to match

matches - list that will accept the matches, or null if one should be created.

Returns:

the list.

listRecursively

public static java.io.File[] listRecursively(java.io.File root,
                                             java.lang.String glob)

Return an array of files where the regex is found at the end. A check is performed to see if the root is case-insensitive.

Parameters:

root - the root of the search (e.g. /fonts/)

glob - the glob to match (e.g. *.ttf)

Returns:

list of files.

fileCopy

public static void fileCopy(java.io.File src,
                            java.io.File dst)
                     throws java.io.FileNotFoundException,
                            java.io.IOException

copies the file or folder from src to dst.

Parameters:

src - the source file or folder.

dst - the location for the new file or folder.

Throws:

java.io.FileNotFoundException

java.io.IOException

getMagic

public static java.lang.String getMagic(java.io.File src)
                                 throws java.io.FileNotFoundException,
                                        java.io.IOException

return the first four bytes of the file as a string. Some magic numbers we care about:

'\x89HDF' HDF (and new NetCDF) files

Parameters:

src -

Returns:

a four byte string

Throws:

java.io.FileNotFoundException

java.lang.IllegalArgumentException - if the file is less than four bytes.

java.io.IOException

readInputStreamToString

public static java.lang.String readInputStreamToString(java.io.InputStream ins)
                                                throws java.io.IOException

read all the bytes in the UTF-8 encoded inputStream into a string.

Parameters:

ins - the input stream

Returns:

string containing the contents of the file.

Throws:

java.io.IOException

readFileToString

public static java.lang.String readFileToString(java.io.File f)
                                         throws java.io.IOException

read all the bytes in the UTF-8 encoded file into a string.

Parameters:

f - the file, which presumed to be UTF-8 (or ASCII) encoded.

Returns:

string containing the contents of the file.

Throws:

java.io.IOException

writeStringToFile

public static void writeStringToFile(java.io.File f,
                                     java.lang.String src)
                              throws java.io.IOException

write all the bytes in the string to a file using UTF-8 encoding.

Parameters:

f - the file name.

src - the string to write to the file.

Throws:

java.io.IOException

lineCount

public static int lineCount(java.io.File f)
                     throws java.io.FileNotFoundException,
                            java.io.IOException

return the number of lines in the text file. Breaking the file into lines is handled by Java's BufferedReader.

Parameters:

f - the file

Returns:

the number of lines.

Throws:

java.io.FileNotFoundException

java.io.IOException

See Also:

BufferedReader

consumeStream

public static int consumeStream(java.io.InputStream in)
                         throws java.io.IOException

read all the bytes off the stream, perhaps to empty a URL response. This does not close the stream!

Parameters:

in - the input stream, which will not be closed by this method.

Returns:

the total number of bytes read.

Throws:

java.io.IOException