com.ansca.corona.storage

Class UniqueFileNameBuilder

java.lang.Object

com.ansca.corona.storage.UniqueFileNameBuilder

public class UniqueFileNameBuilder
extends Object

Generates a unique file name in a given directory. The file name format and its extension is configurable.

Example usage:

    // Create a unique JPEG file name in the "Pictures" directory.
    UniqueFileNameBuilder builder = new UniqueFileNameBuilder();
    builder.setDirectory(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES));
    builder.setFileNameFormat("Picture %d");
    builder.setFileExtension("jpg");
    java.io.File imageFile = builder.build();
    if (imageFile != null) {
       // Unique file name was generated. Create the file here.
    }
 

Constructor Summary

Constructors

Constructor and Description
UniqueFileNameBuilder() Create a new file name builder object.

Method Summary

Methods

Modifier and Type	Method and Description
File	build() Generates a unique file name for the directory that you provided to the setDirectory() method.
File	getDirectory() Gets the directory this builder will generate a unique file name in.
String	getFileExtension() Gets the file extension to be appended to the file name.
String	getFileNameFormat() Gets the file name format string that this builder will use to generate a unique file name.
void	setDirectory(File directory) Sets the directory to generate a unique file name in.
void	setFileExtension(String extension) Sets the file extension to be appended to the file name.
void	setFileNameFormat(String format) Sets the file name format string to be used to genearte a unique file name.

Methods inherited from class java.lang.Object

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

Constructor Detail

UniqueFileNameBuilder

public UniqueFileNameBuilder()

Create a new file name builder object.

Method Detail

setDirectory

public void setDirectory(File directory)

Sets the directory to generate a unique file name in.

Parameters:

directory - The directory's path. This directory is expected to exist or else this object will fail to build a unique file name.

getDirectory

public File getDirectory()

Gets the directory this builder will generate a unique file name in.

Returns:

Returns a File object containing the path to the directory.

Returns null if the directory has not been set yet.

setFileNameFormat

public void setFileNameFormat(String format)

Sets the file name format string to be used to genearte a unique file name.

Parameters:

format - The format string to be used, such as "File %d". This string is expected to have a "%d" in it so that this builder can generate a unique number for the file name. This string is not expected to provide a file extension.

getFileNameFormat

public String getFileNameFormat()

Gets the file name format string that this builder will use to generate a unique file name.

Returns:

Returns the format string used to generate the file name.

setFileExtension

public void setFileExtension(String extension)

Sets the file extension to be appended to the file name.

Parameters:

extension - The extension to be appended to the file name.

Set to null or empty string to not append an extension to the file name.

getFileExtension

public String getFileExtension()

Gets the file extension to be appended to the file name.

Returns:

Returns the extension to be appended to the file name without the leading period.

Returns an empty string if an extension will not be appended.

build

public File build()

Generates a unique file name for the directory that you provided to the setDirectory() method.

Note that this method does not actually create a file in the set directory. This method only generates a unique file name that you can use to create a new file with.

You are expected to call the setDirectory(), setFileNameFormat(), and setFileExtension() methods before calling this build() method.

Returns:

Returns a path and file name that is unique in the set directory.

Returns null if the directory does not exist.