org.foray.common
Class Configuration

java.lang.Object
  org.foray.common.Configuration

Direct Known Subclasses:

OutputConfig, SessionConfig

public abstract class Configuration
extends Object

Abstract superclass for configuration options. All options are stored in key / value pairs. Protected Convenience methods are available to handle Boolean, Int, String, and List values.

Most accessor methods are protected. The purpose is to force clients to use the subclass accessor methods instead, where more intelligence can be applied with regard to handling null values, etc. Applications that wish to make these available should simply override them with public methods in the subclass.

Field Summary

static byte	PRECEDENCE_COMMAND_LINE Constant indicating the highest-level precedence, that of an item set on the command-line.
static byte	PRECEDENCE_CONFIG_FILE Constant indicating the middle-level precedence, that of an item in the configuration file.
static byte	PRECEDENCE_DEFAULT Constant indicating the lowest precedence, that of the default values.

Constructor Summary

protected

Configuration() Constructor.

Method Summary

protected void	addUnvalidatedOption(String key, Object value, int precedenceValue) Adds an item to the configuration without giving the subclass an opportunity to validate it.
String	dumpConfiguration() Returns the contents of this Configuration as a String, suitable for logging.
protected Boolean	getBooleanValue(String key) Convenience method to access boolean values in the configuration.
protected int	getIntValue(String key) Convenience methods to access int values in the configuration.
protected List<?>	getListValue(String key) Convenience method to access list values in the configuration.
protected abstract String	getName() Supplies a name for this configuration.
protected String	getStringValue(String key) Convenience method to access strings values in the configuration.
protected Object	getValue(String key) Accessor method for a generic property.
protected Boolean	parseBoolean(String key, String value) Converts a given configuration item to a Boolean value.
abstract boolean	parseOption(String key, String value, int precedenceValue) Attempt to add the configuration option.
protected String[]	parseSpaceDelimitedList(String key, String value) Converts a given space-delimited configuration item to an ArrayList.
protected URL	parseURL(String key, String urlString) Converts a given configuration item to a URL.
protected URL	parseURLDirectory(String key, String directory) Converts a given configuration item to a URL directory, logging a warning if the resulting URL points to a file instead of a directory.
protected URL	parseURLFile(String key, String fileName) Converts a given configuration item to a URL, logging a warning if the resulting URL points to a directory instead of a file.
protected void	put(String key, Object value, int precedenceValue) Adds or updates a configuration option.
protected abstract void	setDefaults() Sets any default configuration values.

Methods inherited from class java.lang.Object

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

Field Detail

PRECEDENCE_DEFAULT

public static final byte PRECEDENCE_DEFAULT

Constant indicating the lowest precedence, that of the default values.

See Also:

Constant Field Values

PRECEDENCE_CONFIG_FILE

public static final byte PRECEDENCE_CONFIG_FILE

Constant indicating the middle-level precedence, that of an item in the configuration file.

See Also:

Constant Field Values

PRECEDENCE_COMMAND_LINE

public static final byte PRECEDENCE_COMMAND_LINE

Constant indicating the highest-level precedence, that of an item set on the command-line.

See Also:

Constant Field Values

Constructor Detail

Configuration

protected Configuration()

Constructor.

Method Detail

setDefaults

protected abstract void setDefaults()

Sets any default configuration values.

getName

protected abstract String getName()

Supplies a name for this configuration.

Returns:

A name for this configuration, suitable to be used in logging messages.

getValue

protected Object getValue(String key)

Accessor method for a generic property.

Parameters:

key - a string containing the key value for the configuration value

Returns:

Object containing the value; normally you would use one of the convenience methods, which return the correct form, null if the key is not defined.

getStringValue

protected String getStringValue(String key)

Convenience method to access strings values in the configuration.

Parameters:

key - a string containing the key value for the configuration value

Returns:

String a string containing the value, null if the key is not defined.

getIntValue

protected int getIntValue(String key)

Convenience methods to access int values in the configuration.

Parameters:

key - a string containing the key value for the configuration value

Returns:

The int value, or -1 if the key is not defined.

getBooleanValue

protected Boolean getBooleanValue(String key)

Convenience method to access boolean values in the configuration.

Parameters:

key - a string containing the key value for the configuration value

Returns:

The Boolean value, or null if the key is not defined.

getListValue

protected List<?> getListValue(String key)

Convenience method to access list values in the configuration.

Parameters:

key - a string containing the key value for the configuration value

Returns:

The List value, or null if the key is not defined.

put

protected void put(String key,
                   Object value,
                   int precedenceValue)

Adds or updates a configuration option. If the option does not already exist, it is added. If it does exist, its previous precedence value is compared to the precedence asserted by precedenceValue. If precedenceValue is greater than or equal to the previous precedence value, the new value is stored. Otherwise, the old value is retained and the new value is disregarded.

Parameters:

key - A string containing the key value for the configuration value.

value - The object containing the configuration value.

precedenceValue - The precedence with which this option should be treated. Entries with a higher precedence value override entries with a lower value.

parseOption

public abstract boolean parseOption(String key,
                                    String value,
                                    int precedenceValue)
                             throws ConfigurationException

Attempt to add the configuration option.

Parameters:

key - A string containing the key value for the configuration value.

value - The string containing the configuration value.

precedenceValue - The precedence with which this option should be treated. Entries with a higher precedence value override entries with a lower value.

Returns:

True if the option was successfully added, false if it does not belong in this Configuration implementation.

Throws:

ConfigurationException - For an invalid value for the given key.

addUnvalidatedOption

protected void addUnvalidatedOption(String key,
                                    Object value,
                                    int precedenceValue)

Adds an item to the configuration without giving the subclass an opportunity to validate it.

Parameters:

key - A string containing the key value for the configuration value.

value - The object containing the configuration value.

precedenceValue - The precedence with which this option should be treated. Entries with a higher precedence value override entries with a lower value.

parseBoolean

protected Boolean parseBoolean(String key,
                               String value)
                        throws ConfigurationException

Converts a given configuration item to a Boolean value.

Parameters:

key - A string containing the key value for the configuration value.

value - The unparsed boolean value.

Returns:

The parsed Boolean.

Throws:

ConfigurationException - If value is neither "true" nor "false".

parseURLDirectory

protected URL parseURLDirectory(String key,
                                String directory)
                         throws ConfigurationException

Converts a given configuration item to a URL directory, logging a warning if the resulting URL points to a file instead of a directory.

Parameters:

key - A string containing the key value for the configuration value.

directory - The unparsed URL directory value.

Returns:

The parsed URL.

Throws:

ConfigurationException - If directory is malformed, or if it is not a directory.

parseURLFile

protected URL parseURLFile(String key,
                           String fileName)
                    throws ConfigurationException

Converts a given configuration item to a URL, logging a warning if the resulting URL points to a directory instead of a file.

Parameters:

key - A string containing the key value for the configuration value.

fileName - The unparsed URL name.

Returns:

The parsed URL.

Throws:

ConfigurationException - If fileName is malformed, or if it is not a file.

parseURL

protected URL parseURL(String key,
                       String urlString)
                throws ConfigurationException

Converts a given configuration item to a URL.

Parameters:

key - A string containing the key value for the configuration value.

urlString - The unparsed URL name.

Returns:

The parsed URL.

Throws:

ConfigurationException - If urlString is malformed.

parseSpaceDelimitedList

protected String[] parseSpaceDelimitedList(String key,
                                           String value)

Converts a given space-delimited configuration item to an ArrayList.

Parameters:

key - A string containing the key value for the configuration value.

value - The space-delimited input.

Returns:

The parsed List.

dumpConfiguration

public String dumpConfiguration()

Returns the contents of this Configuration as a String, suitable for logging. Usually used for debugging.

Returns:

The contents of this Configuration.