org.apache.commons.configuration
Interface Configuration

All Known Subinterfaces:

FileConfiguration

All Known Implementing Classes:

AbstractConfiguration, AbstractFileConfiguration, XMLConfiguration

public interface Configuration

Configuration interface.

Version:

$Id: Configuration.java 155408 2005-02-26 12:56:39Z dirkv $

Method Summary

void	addProperty(String key, Object value) Add a property to the configuration.
void	clear() Remove all properties from the configuration.
void	clearProperty(String key) Remove a property from the configuration.
boolean	containsKey(String key) Check if the configuration contains the specified key.
BigDecimal	getBigDecimal(String key) Get a BigDecimal associated with the given configuration key.
BigDecimal	getBigDecimal(String key, BigDecimal defaultValue) Get a BigDecimal associated with the given configuration key.
BigInteger	getBigInteger(String key) Get a BigInteger associated with the given configuration key.
BigInteger	getBigInteger(String key, BigInteger defaultValue) Get a BigInteger associated with the given configuration key.
boolean	getBoolean(String key) Get a boolean associated with the given configuration key.
boolean	getBoolean(String key, boolean defaultValue) Get a boolean associated with the given configuration key.
Boolean	getBoolean(String key, Boolean defaultValue) Get a Boolean associated with the given configuration key.
byte	getByte(String key) Get a byte associated with the given configuration key.
byte	getByte(String key, byte defaultValue) Get a byte associated with the given configuration key.
Byte	getByte(String key, Byte defaultValue) Get a Byte associated with the given configuration key.
double	getDouble(String key) Get a double associated with the given configuration key.
double	getDouble(String key, double defaultValue) Get a double associated with the given configuration key.
Double	getDouble(String key, Double defaultValue) Get a Double associated with the given configuration key.
float	getFloat(String key) Get a float associated with the given configuration key.
float	getFloat(String key, float defaultValue) Get a float associated with the given configuration key.
Float	getFloat(String key, Float defaultValue) Get a Float associated with the given configuration key.
int	getInt(String key) Get a int associated with the given configuration key.
int	getInt(String key, int defaultValue) Get a int associated with the given configuration key.
Integer	getInteger(String key, Integer defaultValue) Get an Integer associated with the given configuration key.
Iterator	getKeys() Get the list of the keys contained in the configuration.
Iterator	getKeys(String prefix) Get the list of the keys contained in the configuration that match the specified prefix.
List	getList(String key) Get a List of strings associated with the given configuration key.
List	getList(String key, List defaultValue) Get a List of strings associated with the given configuration key.
long	getLong(String key) Get a long associated with the given configuration key.
long	getLong(String key, long defaultValue) Get a long associated with the given configuration key.
Long	getLong(String key, Long defaultValue) Get a Long associated with the given configuration key.
Properties	getProperties(String key) Get a list of properties associated with the given configuration key.
Object	getProperty(String key) Gets a property from the configuration.
short	getShort(String key) Get a short associated with the given configuration key.
short	getShort(String key, short defaultValue) Get a short associated with the given configuration key.
Short	getShort(String key, Short defaultValue) Get a Short associated with the given configuration key.
String	getString(String key) Get a string associated with the given configuration key.
String	getString(String key, String defaultValue) Get a string associated with the given configuration key.
String[]	getStringArray(String key) Get an array of strings associated with the given configuration key.
boolean	isEmpty() Check if the configuration is empty.
void	setProperty(String key, Object value) Set a property, this will replace any previously set values.
Configuration	subset(String prefix) Return a decorator Configuration containing every key from the current Configuration that starts with the specified prefix.

Method Detail

subset

public Configuration subset(String prefix)

Return a decorator Configuration containing every key from the current Configuration that starts with the specified prefix. The prefix is removed from the keys in the subset. For example, if the configuration contains the following properties:

    prefix.number = 1
    prefix.string = Apache
    prefixed.foo = bar
    prefix = Jakarta

the Configuration returned by subset("prefix") will contain the properties:

    number = 1
    string = Apache
    = Jakarta

(The key for the value "Jakarta" is an empty string)

Since the subset is a decorator and not a modified copy of the initial Configuration, any change made to the subset is available to the Configuration, and reciprocally.

Parameters:

prefix - The prefix used to select the properties.

See Also:

SubsetConfiguration

isEmpty

public boolean isEmpty()

Check if the configuration is empty.

Returns:

true if the configuration contains no property, false otherwise.

containsKey

public boolean containsKey(String key)

Check if the configuration contains the specified key.

Parameters:

key - the key whose presence in this configuration is to be tested

Returns:

true if the configuration contains a value for this key, false otherwise

addProperty

public void addProperty(String key,
                        Object value)

Add a property to the configuration. If it already exists then the value stated here will be added to the configuration entry. For example, if the property:

resource.loader = file

is already present in the configuration and you call

addProperty("resource.loader", "classpath")

Then you will end up with a List like the following:

["file", "classpath"]

Parameters:

key - The key to add the property to.

value - The value to add.

setProperty

public void setProperty(String key,
                        Object value)

Set a property, this will replace any previously set values. Set values is implicitly a call to clearProperty(key), addProperty(key, value).

Parameters:

key - The key of the property to change

value - The new value

clearProperty

public void clearProperty(String key)

Remove a property from the configuration.

Parameters:

key - the key to remove along with corresponding value.

clear

public void clear()

Remove all properties from the configuration.

getProperty

public Object getProperty(String key)

Gets a property from the configuration.

Parameters:

key - property to retrieve

Returns:

the value to which this configuration maps the specified key, or null if the configuration contains no mapping for this key.

getKeys

public Iterator getKeys(String prefix)

Get the list of the keys contained in the configuration that match the specified prefix.

Parameters:

prefix - The prefix to test against.

Returns:

An Iterator of keys that match the prefix.

getKeys

public Iterator getKeys()

Get the list of the keys contained in the configuration.

Returns:

An Iterator.

getProperties

public Properties getProperties(String key)

Get a list of properties associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated properties if key is found.

Throws:

ConversionException - is thrown if the key maps to an object that is not a String/List.

IllegalArgumentException - if one of the tokens is malformed (does not contain an equals sign).

getBoolean

public boolean getBoolean(String key)

Get a boolean associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated boolean.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Boolean.

getBoolean

public boolean getBoolean(String key,
                          boolean defaultValue)

Get a boolean associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated boolean.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Boolean.

getBoolean

public Boolean getBoolean(String key,
                          Boolean defaultValue)
                   throws NoClassDefFoundError

Get a Boolean associated with the given configuration key.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated boolean if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Boolean.

NoClassDefFoundError

getByte

public byte getByte(String key)

Get a byte associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated byte.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Byte.

getByte

public byte getByte(String key,
                    byte defaultValue)

Get a byte associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated byte.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Byte.

getByte

public Byte getByte(String key,
                    Byte defaultValue)

Get a Byte associated with the given configuration key.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated byte if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Byte.

getDouble

public double getDouble(String key)

Get a double associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated double.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Double.

getDouble

public double getDouble(String key,
                        double defaultValue)

Get a double associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated double.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Double.

getDouble

public Double getDouble(String key,
                        Double defaultValue)

Get a Double associated with the given configuration key.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated double if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Double.

getFloat

public float getFloat(String key)

Get a float associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated float.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Float.

getFloat

public float getFloat(String key,
                      float defaultValue)

Get a float associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated float.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Float.

getFloat

public Float getFloat(String key,
                      Float defaultValue)

Get a Float associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated float if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Float.

getInt

public int getInt(String key)

Get a int associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated int.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Integer.

getInt

public int getInt(String key,
                  int defaultValue)

Get a int associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated int.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Integer.

getInteger

public Integer getInteger(String key,
                          Integer defaultValue)

Get an Integer associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated int if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Integer.

getLong

public long getLong(String key)

Get a long associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated long.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Long.

getLong

public long getLong(String key,
                    long defaultValue)

Get a long associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated long.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Long.

getLong

public Long getLong(String key,
                    Long defaultValue)

Get a Long associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated long if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Long.

getShort

public short getShort(String key)

Get a short associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated short.

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

ConversionException - is thrown if the key maps to an object that is not a Short.

getShort

public short getShort(String key,
                      short defaultValue)

Get a short associated with the given configuration key.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated short.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Short.

getShort

public Short getShort(String key,
                      Short defaultValue)

Get a Short associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated short if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a Short.

NoSuchElementException - is thrown if the key doesn't map to an existing object.

getBigDecimal

public BigDecimal getBigDecimal(String key)

Get a BigDecimal associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated BigDecimal if key is found and has valid format

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

getBigDecimal

public BigDecimal getBigDecimal(String key,
                                BigDecimal defaultValue)

Get a BigDecimal associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated BigDecimal if key is found and has valid format, default value otherwise.

getBigInteger

public BigInteger getBigInteger(String key)

Get a BigInteger associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated BigInteger if key is found and has valid format

Throws:

NoSuchElementException - is thrown if the key doesn't map to an existing object.

getBigInteger

public BigInteger getBigInteger(String key,
                                BigInteger defaultValue)

Get a BigInteger associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated BigInteger if key is found and has valid format, default value otherwise.

getString

public String getString(String key)

Get a string associated with the given configuration key.

Parameters:

key - The configuration key.

Returns:

The associated string.

Throws:

ConversionException - is thrown if the key maps to an object that is not a String.

NoSuchElementException - is thrown if the key doesn't map to an existing object.

getString

public String getString(String key,
                        String defaultValue)

Get a string associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated string if key is found and has valid format, default value otherwise.

Throws:

ConversionException - is thrown if the key maps to an object that is not a String.

getStringArray

public String[] getStringArray(String key)

Get an array of strings associated with the given configuration key. If the key doesn't map to an existing object an empty array is returned

Parameters:

key - The configuration key.

Returns:

The associated string array if key is found.

Throws:

ConversionException - is thrown if the key maps to an object that is not a String/List of Strings.

getList

public List getList(String key)

Get a List of strings associated with the given configuration key. If the key doesn't map to an existing object an empty List is returned.

Parameters:

key - The configuration key.

Returns:

The associated List.

Throws:

ConversionException - is thrown if the key maps to an object that is not a List.

getList

public List getList(String key,
                    List defaultValue)

Get a List of strings associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated List of strings.

Throws:

ConversionException - is thrown if the key maps to an object that is not a List.