org.crosswire.common.util

Class NetUtil

java.lang.Object

org.crosswire.common.util.NetUtil

public final class NetUtil
extends Object

The NetUtil class looks after general utility stuff around the java.net package.

Author:

Joe Walker, Mark Goodwin, DM Smith

See Also:

The GNU Lesser General Public License for details.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NetUtil.IsDirectoryURIFilter Check that the directories in the version directory really represent versions.
static class	NetUtil.URIFilterFilenameFilter Quick implementation of FilenameFilter that uses a URIFilter

Field Summary

Fields

Modifier and Type	Field and Description
static String	AUTH_SEPERATOR_PASSWORD Separating the password from the username
static String	AUTH_SEPERATOR_USERNAME Separating the username from the rest of the URL/URI
private static File	cachedir Where are temporary files cached.
static String	INDEX_FILE For directory listings
private static org.slf4j.Logger	LOGGER The log stream
static String	PROTOCOL_FILE Constant for the file: protocol or scheme
static String	PROTOCOL_FTP Constant for the ftp: protocol or scheme
static String	PROTOCOL_HTTP Constant for the http: protocol or scheme
static String	PROTOCOL_JAR Constant for the jar: protocol or scheme
static String	SEPARATOR URL/URI separator
private static String	TEMP_SUFFIX The temporary suffix, used when a temporary file is needed in the system's temporary directory.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	NetUtil() Basic constructor - ensure that we can't be instantiated

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	canRead(URI orig) If there is a readable directory or file at the other end of this URI return true.
static boolean	canWrite(URI orig) If there is a writable directory or file at the other end of this URI return true.
private static void	checkFileURI(URI uri) Throw if the given URI does not use the 'file:' protocol
static URI	copy(URI uri)
static boolean	delete(URI orig) Delete a URI.
static File	getAsFile(URI uri) Return a File from the URI either by extracting from a file: URI or by downloading to a temp dir first
static InputStream	getInputStream(URI uri) Attempt to obtain an InputStream from a URI.
static long	getLastModified(URI uri) When was the given URI last modified.
static long	getLastModified(URI uri, String proxyHost) When was the given URI last modified.
static long	getLastModified(URI uri, String proxyHost, Integer proxyPort) When was the given URI last modified.
static OutputStream	getOutputStream(URI uri) Attempt to obtain an OutputStream from a URI.
static OutputStream	getOutputStream(URI uri, boolean append) Attempt to obtain an OutputStream from a URI.
static int	getSize(URI uri)
static int	getSize(URI uri, String proxyHost)
static int	getSize(URI uri, String proxyHost, Integer proxyPort)
static URI	getTemporaryURI(String prefix, String suffix) A URI version of File.createTempFile()
static URI	getURI(File file) Get a URI version of the given file.
static File	getURICacheDir() Returns the cache directory.
static boolean	isDirectory(URI orig) If there is a directory at the other end of this URI return true.
static boolean	isFile(URI uri) If there is a file at the other end of this URI return true.
static boolean	isNewer(URI left, URI right) Returns whether the left is newer than the right by comparing their last modified dates.
static boolean	isNewer(URI left, URI right, String proxyHost) Returns whether the left is newer than the right by comparing their last modified dates.
static boolean	isNewer(URI left, URI right, String proxyHost, Integer proxyPort) Returns whether the left is newer than the right by comparing their last modified dates.
private static boolean	isSeparator(char c)
static URI	lengthenURI(URI orig, String anExtra) Utility to add a string to the end of a URI.
static String[]	list(URI uri, URIFilter filter) List the items available assuming that this URI points to a directory.
static String[]	listByFile(URI uri, URIFilter filter) List all the files specified by the index file passed in.
static String[]	listByIndexFile(URI index) List all the strings specified by the index file passed in.
static String[]	listByIndexFile(URI index, URIFilter filter) List all the files specified by the index file passed in.
static PropertyMap	loadProperties(URI uri) Load up properties given by a URI.
static void	makeDirectory(URI orig) If the directory does not exist, create it.
static void	makeFile(URI orig) If the file does not exist, create it.
static boolean	move(URI oldUri, URI newUri) Move a URI from one place to another.
static void	setURICacheDir(File cachedir) Sets the cache directory.
static URI	shortenURI(URI orig, String strip) Utility to strip a string from the end of a URI.
static void	storeProperties(PropertyMap properties, URI uri, String title) Store the properties at the location given by the uri using the supplied title.
static URI	toURI(URL url) Convert an URL to an URI.
static URL	toURL(URI uri) Convert an URI to an URL.

Methods inherited from class java.lang.Object

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

Field Detail

PROTOCOL_FILE

public static final String PROTOCOL_FILE

Constant for the file: protocol or scheme

See Also:

Constant Field Values

PROTOCOL_HTTP

public static final String PROTOCOL_HTTP

Constant for the http: protocol or scheme

See Also:

Constant Field Values

PROTOCOL_FTP

public static final String PROTOCOL_FTP

Constant for the ftp: protocol or scheme

See Also:

Constant Field Values

PROTOCOL_JAR

public static final String PROTOCOL_JAR

Constant for the jar: protocol or scheme

See Also:

Constant Field Values

INDEX_FILE

public static final String INDEX_FILE

For directory listings

See Also:

Constant Field Values

SEPARATOR

public static final String SEPARATOR

URL/URI separator

See Also:

Constant Field Values

AUTH_SEPERATOR_USERNAME

public static final String AUTH_SEPERATOR_USERNAME

Separating the username from the rest of the URL/URI

See Also:

Constant Field Values

AUTH_SEPERATOR_PASSWORD

public static final String AUTH_SEPERATOR_PASSWORD

Separating the password from the username

See Also:

Constant Field Values

TEMP_SUFFIX

private static final String TEMP_SUFFIX

The temporary suffix, used when a temporary file is needed in the system's temporary directory.

See Also:

Constant Field Values

cachedir

private static File cachedir

Where are temporary files cached.

LOGGER

private static final org.slf4j.Logger LOGGER

The log stream

Constructor Detail

NetUtil

private NetUtil()

Basic constructor - ensure that we can't be instantiated

Method Detail

copy

public static URI copy(URI uri)

makeDirectory

public static void makeDirectory(URI orig)
                          throws MalformedURLException

If the directory does not exist, create it. Note this currently only works with file: type URIs

Parameters:

orig - The directory URI to create

Throws:

MalformedURLException - If the URI is not valid

makeFile

public static void makeFile(URI orig)
                     throws MalformedURLException,
                            IOException

If the file does not exist, create it. Note this currently only works with file: type URIs

Parameters:

orig - The file URI to create

Throws:

MalformedURLException - If the URI is not valid

IOException - a problem with I/O happened

isFile

public static boolean isFile(URI uri)

If there is a file at the other end of this URI return true.

Parameters:

uri - The URI to check

Returns:

true if the URI points at a file

isDirectory

public static boolean isDirectory(URI orig)

If there is a directory at the other end of this URI return true. Note non file: type URI will always return false

Parameters:

orig - The URI to check

Returns:

true if the URI points at a file: directory

canWrite

public static boolean canWrite(URI orig)

If there is a writable directory or file at the other end of this URI return true. Note non file: type URIs will always return false

Parameters:

orig - The URI to check

Returns:

true if the URI points at a writable file or directory

canRead

public static boolean canRead(URI orig)

If there is a readable directory or file at the other end of this URI return true. Note non file: type URIs will always return false

Parameters:

orig - The URI to check

Returns:

true if the URI points at a readable file or directory

move

public static boolean move(URI oldUri,
           URI newUri)
                    throws IOException

Move a URI from one place to another. Currently this only works for file: URIs, however the interface should not need to change to handle more complex URIs

Parameters:

oldUri - The URI to move

newUri - The destination URI

Returns:

whether the move happened

Throws:

IOException - a problem with I/O happened

delete

public static boolean delete(URI orig)
                      throws IOException

Delete a URI. Currently this only works for file: URIs, however the interface should not need to change to handle more complex URIs

Parameters:

orig - The URI to delete

Returns:

whether the deleted happened

Throws:

IOException - a problem with I/O happened

getAsFile

public static File getAsFile(URI uri)
                      throws IOException

Return a File from the URI either by extracting from a file: URI or by downloading to a temp dir first

Parameters:

uri - The original URI to the file.

Returns:

The URI as a file

Throws:

IOException - a problem with I/O happened

shortenURI

public static URI shortenURI(URI orig,
             String strip)
                      throws MalformedURLException

Utility to strip a string from the end of a URI.

Parameters:

orig - The URI to strip

strip - The text to strip from the end of the URI

Returns:

The stripped URI

Throws:

MalformedURLException - If the URI does not end in the given text

lengthenURI

public static URI lengthenURI(URI orig,
              String anExtra)

Utility to add a string to the end of a URI.

Parameters:

orig - The URI to lengthen

anExtra - The text to add to the end of the URI

Returns:

The lengthened URI

isSeparator

private static boolean isSeparator(char c)

getInputStream

public static InputStream getInputStream(URI uri)
                                  throws IOException

Attempt to obtain an InputStream from a URI. If the URI is a file scheme then just open it directly. Otherwise, call uri.toURL().openStream().

Parameters:

uri - The URI to attempt to read from

Returns:

An InputStream connection

Throws:

IOException - a problem with I/O happened

getOutputStream

public static OutputStream getOutputStream(URI uri)
                                    throws IOException

Attempt to obtain an OutputStream from a URI. The simple case will open it if it is local. Otherwise, it will call uri.toURL().openConnection().getOutputStream(), however in some JVMs (MS at least this fails where new FileOutputStream(url) works.

Parameters:

uri - The URI to attempt to write to

Returns:

An OutputStream connection

Throws:

IOException - a problem with I/O happened

getOutputStream

public static OutputStream getOutputStream(URI uri,
                           boolean append)
                                    throws IOException

Attempt to obtain an OutputStream from a URI. The simple case will open it if it is local. Otherwise, it will call uri.toURL().openConnection().getOutputStream(), however in some JVMs (MS at least this fails where new FileOutputStream(url) works.

Parameters:

uri - The URI to attempt to write to

append - Do we write to the end of the file instead of the beginning

Returns:

An OutputStream connection

Throws:

IOException - a problem with I/O happened

list

public static String[] list(URI uri,
            URIFilter filter)
                     throws MalformedURLException,
                            IOException

List the items available assuming that this URI points to a directory.

There are 2 methods of calculating the answer - if the URI is a file: URI then we can just use File.list(), otherwise we ask for a file inside the directory called index.txt and assume the directories contents to be listed one per line.

If the URI is a file: URI then we execute both methods and warn if there is a difference, but returning the values from the index.txt method.

Parameters:

uri - the URI to list

filter - the filter for the listing

Returns:

the filtered list

Throws:

MalformedURLException - If the URI is not valid

IOException - a problem with I/O happened

listByFile

public static String[] listByFile(URI uri,
                  URIFilter filter)
                           throws MalformedURLException

List all the files specified by the index file passed in.

Parameters:

uri - the URI to list

filter - the filter for the listing

Returns:

the filtered list

Throws:

MalformedURLException - If the URI is not valid

listByIndexFile

public static String[] listByIndexFile(URI index)
                                throws IOException

List all the strings specified by the index file passed in. To be acceptable it must be a non-0 length string, not commented with #, and not the index file itself.

Parameters:

index - the URI to list

Returns:

the list.

Throws:

IOException - a problem with I/O happened

listByIndexFile

public static String[] listByIndexFile(URI index,
                       URIFilter filter)
                                throws IOException

List all the files specified by the index file passed in.

Each line is pre-processed:

• Ignore comments (# to end of line)
• Trim spaces from line.
• Ignore blank lines.

To be acceptable it:

• cannot be the index file itself
• and must acceptable by the filter.

Parameters:

index - the URI to list

filter - the filter for the listing

Returns:

the list.

Throws:

IOException - a problem with I/O happened

loadProperties

public static PropertyMap loadProperties(URI uri)
                                  throws IOException

Load up properties given by a URI.

Parameters:

uri - the location of the properties

Returns:

the properties given by the URI

Throws:

IOException - a problem with I/O happened

storeProperties

public static void storeProperties(PropertyMap properties,
                   URI uri,
                   String title)
                            throws IOException

Store the properties at the location given by the uri using the supplied title.

Parameters:

properties - the properties to store

uri - the location of the store

title - the label held in the properties file

Throws:

IOException - a problem with I/O happened

getSize

public static int getSize(URI uri)

Parameters:

uri - the resource whose size is wanted

Returns:

the size of that resource

getSize

public static int getSize(URI uri,
          String proxyHost)

getSize

public static int getSize(URI uri,
          String proxyHost,
          Integer proxyPort)

getLastModified

public static long getLastModified(URI uri)

When was the given URI last modified. If no modification time is available then this method return the current time.

Parameters:

uri - the URI to examine

Returns:

the last modified date

getLastModified

public static long getLastModified(URI uri,
                   String proxyHost)

When was the given URI last modified. If no modification time is available then this method return the current time.

Parameters:

uri - the URI to examine

proxyHost - the proxy host

Returns:

the last modified date

getLastModified

public static long getLastModified(URI uri,
                   String proxyHost,
                   Integer proxyPort)

When was the given URI last modified. If no modification time is available then this method return the current time.

Parameters:

uri - the URI to examine

proxyHost - the proxy host

proxyPort - the proxy port

Returns:

the last modified date

isNewer

public static boolean isNewer(URI left,
              URI right)

Returns whether the left is newer than the right by comparing their last modified dates.

Parameters:

left - one URI to compare

right - the other URI to compare

Returns:

true if the left is newer

isNewer

public static boolean isNewer(URI left,
              URI right,
              String proxyHost)

Returns whether the left is newer than the right by comparing their last modified dates.

Parameters:

left - one URI to compare

right - the other URI to compare

proxyHost - the proxy host

Returns:

true if the left is newer

isNewer

public static boolean isNewer(URI left,
              URI right,
              String proxyHost,
              Integer proxyPort)

Returns whether the left is newer than the right by comparing their last modified dates.

Parameters:

left - one URI to compare

right - the other URI to compare

proxyHost - the proxy host

proxyPort - the proxy port

Returns:

true if the left is newer

checkFileURI

private static void checkFileURI(URI uri)
                          throws MalformedURLException

Throw if the given URI does not use the 'file:' protocol

Parameters:

uri - The URI to check

Throws:

MalformedURLException - If the protocol is not file:

getURICacheDir

public static File getURICacheDir()

Returns the cache directory.

Returns:

File

setURICacheDir

public static void setURICacheDir(File cachedir)

Sets the cache directory.

Parameters:

cachedir - The cache directory to set

getURI

public static URI getURI(File file)

Get a URI version of the given file.

Parameters:

file - The File to turn into a URI

Returns:

a URI for the given file

getTemporaryURI

public static URI getTemporaryURI(String prefix,
                  String suffix)
                           throws IOException

A URI version of File.createTempFile()

Parameters:

prefix - the prefix of the temporary file

suffix - the suffix of the temporary file

Returns:

A new temporary URI

Throws:

IOException - If something goes wrong creating the temp URI

toURI

public static URI toURI(URL url)

Convert an URL to an URI.

Parameters:

url - to convert

Returns:

the URI representation of the URL

toURL

public static URL toURL(URI uri)

Convert an URI to an URL.

Parameters:

uri - to convert

Returns:

the URL representation of the URI