bradleyross.library.helpers

Class FileHelpers

java.lang.Object

bradleyross.library.helpers.FileHelpers

public class FileHelpers
extends Object

Methods to read and write files designed to be used within other programs.

Note: SocketTimeoutException is a subclass of IOException.

Note: Using the URLConnection.setReadTimeout(int) and URLConnection.setConnectTimeout(int) methods should prevent the methods in this class from hanging.

It looks like the best approach is to rerun the process if an error occurs. Start with small timeout values and increase them on each iteration.

Author:

Bradley Ross

Field Summary

Fields

Modifier and Type	Field and Description
protected static long	combinedTime Timeout for entire transfer in milliseconds.
protected static int	connectTimeout Length of time allowed for connect operations.
protected static int	debugLevel Determines quantity of diagnostic output to be generated.
protected static int	readTimeout Length of time allowed for read operations.
protected static int	timeout Deprecated.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FileHelpers() Since all of the methods and fields are static, the constructor should never be used.

Method Summary

Methods

Modifier and Type	Method and Description
static void	copyFile(File input, File output) Copy a file.
static void	copyFile(String inputFileName, String outputFileName) Copy a file.
static void	fixDirs(File newFile) Checks to see if directories for a file exist, and then creates directories as appropriate.
static void	fixDirs(String name) Checks to see if directories for a file exist, and then creates directories as appropriate.
static void	getBytes(File input, OutputStream output) Read the contents of a a file and then sends the data to a OutputStream object.
static void	getBytes(URL url, File file) Read the contents of a URL into a file, passing the data as byte (binary) stream.
static void	getBytes(URL url, OutputStream output) Read the contents of a a URL and then sends the data to a OutputStream object.
static long	getCombinedTime() Getter for combinedTime
static int	getConnectTimeout() Getter for connectTimeout.
static int	getDebugLevel() Getter for debugLevel
static int	getReadTimeout() Getter for readTimeout.
int	getTimeout() Deprecated.
static String[]	lineSplitterCommas(String input) Split a line into tokens using commas as the field separators.
static String[]	lineSplitterSpaces(String input) Split a line into tokens using spaces as the field separators.
static void	main(String[] args) This is a test driver to check out the copyFile method.
protected static int	power(int i) Calculates 2 to the power i as a helper in determining timings for some of the operations.
static String	readTextFile(String name) Reads the contents of a text file into a String object given the name of the file.
static String	readTextFile(URL address) Read the contents referenced by a URL into a String object.
static void	sendBytes(File output, InputStream input) Send the contents of an InputStream to a File.
static void	sendBytes(URL address, byte[] data) Write the contents of a byte array to a URL as a binary data stream.
static void	sendBytes(URL address, File data) Write the contents of a file to a URL, passing the data as a byte stream (binary data).
static void	setCombinedTime(long value) Setter for combinedTimeout
static void	setConnectTimeout(int value) Setter for connectTimeout.
static void	setDebugLevel(int value) Setter for debugLevel
static void	setReadTimeout(int value) Setter for readTimeout.
void	setTimeout(int value) Deprecated.
static void	showProperties(URLConnection connection) Send properties for connection to System.out
static void	thumbnail(File input, File output, int sizeX, int sizeY) Create a file containing a thumbnail image from another file.
static void	thumbnail(String input, String output) Makes file with thumbnail image
static void	thumbnail(String input, String output, int size) Makes file with thumbnail image
static void	thumbnail(String inputFile, String outputFile, int sizeX, int sizeY) Create a file containing a thumbnail image from another file.

Methods inherited from class java.lang.Object

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

Field Detail

timeout

protected static int timeout

Deprecated.

Number of milliseconds to wait for a read or socket operation.

See Also:

getTimeout(), setTimeout(int), URLConnection.setReadTimeout(int), URLConnection.setConnectTimeout(int)

connectTimeout

protected static int connectTimeout

Length of time allowed for connect operations.

See Also:

URLConnection.setConnectTimeout(int), setConnectTimeout(int), getConnectTimeout()

readTimeout

protected static int readTimeout

Length of time allowed for read operations.

See Also:

URLConnection.setReadTimeout(int), setReadTimeout(int), getReadTimeout()

combinedTime

protected static long combinedTime

Timeout for entire transfer in milliseconds.

See Also:

getCombinedTime(), setConnectTimeout(int)

debugLevel

protected static int debugLevel

Determines quantity of diagnostic output to be generated.

See Also:

getDebugLevel(), setDebugLevel(int)

Constructor Detail

FileHelpers

protected FileHelpers()

Since all of the methods and fields are static, the constructor should never be used.

Method Detail

getConnectTimeout

public static int getConnectTimeout()

Getter for connectTimeout.

Returns:

Timeout value for connect operations

See Also:

connectTimeout

setConnectTimeout

public static void setConnectTimeout(int value)

Setter for connectTimeout.

Parameters:

value - Value to be used for timeout for socket operations.

See Also:

connectTimeout

getReadTimeout

public static int getReadTimeout()

Getter for readTimeout.

Returns:

Timeout value for socket operations

See Also:

readTimeout

setReadTimeout

public static void setReadTimeout(int value)

Setter for readTimeout.

Parameters:

value - Value to be used for timeout for read operations

See Also:

readTimeout

getCombinedTime

public static long getCombinedTime()

Getter for combinedTime

Returns:

Milliseconds allowed for entire file transfer

See Also:

combinedTime

setCombinedTime

public static void setCombinedTime(long value)

Setter for combinedTimeout

Parameters:

value - Number of milliseconds to be allowed for the entire file transfer

See Also:

combinedTime

setTimeout

public void setTimeout(int value)

Deprecated.

Setter for timeout.

Parameters:

value - Milliseconds to wait for read or socket operation

See Also:

timeout

getTimeout

public int getTimeout()

Deprecated.

Getter for timeout

Returns:

Milliseconds to wait for read or socket operation

See Also:

timeout

getDebugLevel

public static int getDebugLevel()

Getter for debugLevel

Returns:

Value of debugLevel

See Also:

debugLevel

setDebugLevel

public static void setDebugLevel(int value)

Setter for debugLevel

Parameters:

value - to be used for debugLevel

See Also:

debugLevel

power

protected static int power(int i)

Calculates 2 to the power i as a helper in determining timings for some of the operations.

Parameters:

i - Power to which 2 is raised

Returns:

2 to the power i

readTextFile

public static String readTextFile(String name)
                           throws IOException

Reads the contents of a text file into a String object given the name of the file.

Parameters:

name - File name

Returns:

Contents of file

Throws:

IOException

readTextFile

public static String readTextFile(URL address)
                           throws IOException

Read the contents referenced by a URL into a String object.

The java.net.URL object required as a parameter is created by a call of the type java.net.URL url = new java.net.URL(urlString) where urlString is a String object containing the URL identifier.

This should only be used for text files. Results are unpredictable and probably undesirable when working with binary files.

• ftp: ftp://userid:password@host:port/file

• file: file:// (file name starting with / indicating root)

Parameters:

address - URL of desired contents

Returns:

String

Throws:

IOException

sendBytes

public static void sendBytes(URL address,
             byte[] data)
                      throws IOException

Write the contents of a byte array to a URL as a binary data stream.

It appears that you can write to protocol ftp but not to protocol file.

Parameters:

address - URL of destination

data - Byte array to be sent

Throws:

IOException

SocketTimeoutException

See Also:

URLConnection

sendBytes

public static void sendBytes(URL address,
             File data)
                      throws IOException

Write the contents of a file to a URL, passing the data as a byte stream (binary data).

Parameters:

address - URL of destination

data - File object containing data to be sent

Throws:

IOException

sendBytes

public static void sendBytes(File output,
             InputStream input)

Send the contents of an InputStream to a File.

Parameters:

output - File object for output.

input - InputStream for input.

getBytes

public static void getBytes(URL url,
            File file)
                     throws IOException

Read the contents of a URL into a file, passing the data as byte (binary) stream.

In case of failure, the algorithm retries with increased values of connectTimeout and readTimeout.

This modification may eventually be added to the other methods.

Parameters:

url - Location of data to be read

file - File where data is to be written

Throws:

IOException

See Also:

URLConnection.setReadTimeout(int), URLConnection.setConnectTimeout(int)

getBytes

public static void getBytes(File input,
            OutputStream output)
                     throws IOException

Read the contents of a a file and then sends the data to a OutputStream object.

Parameters:

input - File containing data to be written

output - OutputStream object where data is to be written

Throws:

IOException

See Also:

File

getBytes

public static void getBytes(URL url,
            OutputStream output)
                     throws IOException

Read the contents of a a URL and then sends the data to a OutputStream object.

Parameters:

url - URL of item to be copied

output - OutputStream object where data is to be written

Throws:

IOException

copyFile

public static void copyFile(File input,
            File output)
                     throws IOException

Copy a file.

Parameters:

input - File object for file to be copied

output - File object for copy of file to be created

Throws:

IOException

See Also:

FileOutputStream

copyFile

public static void copyFile(String inputFileName,
            String outputFileName)
                     throws IOException

Copy a file.

Parameters:

inputFileName - Name of file to be copied

outputFileName - Name of copy of file to be created

Throws:

IOException

See Also:

TestCopyFile

fixDirs

public static void fixDirs(File newFile)
                    throws IOException

Checks to see if directories for a file exist, and then creates directories as appropriate.

Parameters:

newFile - File object to be created

Throws:

IOException

See Also:

File

fixDirs

public static void fixDirs(String name)
                    throws IOException

Checks to see if directories for a file exist, and then creates directories as appropriate.

Parameters:

name - Name of file or directory to be created

Throws:

IOException

See Also:

File

showProperties

public static void showProperties(URLConnection connection)

Send properties for connection to System.out

This is intended for diagnostic purposes.

Parameters:

connection - Connection object

main

public static void main(String[] args)

This is a test driver to check out the copyFile method.

Parameters:

args - Names of original file and copy to be created

lineSplitterSpaces

public static String[] lineSplitterSpaces(String input)

Split a line into tokens using spaces as the field separators.

This method can be used as an example of processing regular expressions in Java.

Parameters:

input - Line to be split into tokens

Returns:

Array of strings containing the tokens.

lineSplitterCommas

public static String[] lineSplitterCommas(String input)

Split a line into tokens using commas as the field separators.

The space is suffixed to the input parameter because the system doesn't seem to recognize a comma as the last character in the string as signifying a new token.

Parameters:

input - Line to be split into tokens

Returns:

Array of strings containing the tokens.

thumbnail

public static void thumbnail(String inputFile,
             String outputFile,
             int sizeX,
             int sizeY)
                      throws IOException

Create a file containing a thumbnail image from another file.

Parameters:

inputFile - Name of file to be read

outputFile - Name of file to be generated

sizeX - Width of generated image in pixels

sizeY - Height of generated image in pixels

Throws:

IOException

See Also:

BufferedImage, ImageIO, RenderedImage

thumbnail

public static void thumbnail(File input,
             File output,
             int sizeX,
             int sizeY)
                      throws IOException

Create a file containing a thumbnail image from another file.

Parameters:

input - file to be read

output - file to be generated

sizeX - Width of generated image in pixels

sizeY - Height of generated image in pixels

Throws:

IOException

See Also:

BufferedImage, ImageIO, RenderedImage

thumbnail

public static void thumbnail(String input,
             String output,
             int size)
                      throws IOException

Makes file with thumbnail image

Parameters:

input - Input file

output - Output file

size - Height and width of output image in pixels

Throws:

IOException

thumbnail

public static void thumbnail(String input,
             String output)
                      throws IOException

Makes file with thumbnail image

Parameters:

input - Input file

output - Output file

Throws:

IOException