org.apache.commons.configuration
public interface Configuration
The main Configuration interface.
This interface allows accessing and manipulating a configuration object.
The major part of the methods defined in this interface deals with accessing
properties of various data types. There is a generic getProperty()
method, which returns the value of the queried property in its raw data
type. Other getter methods try to convert this raw data type into a specific
data type. If this fails, a ConversionException
will be thrown.
For most of the property getter methods an overloaded version exists that
allows to specify a default value, which will be returned if the queried
property cannot be found in the configuration. The behavior of the methods
that do not take a default value in case of a missing property is not defined
by this interface and depends on a concrete implementation. E.g. the
AbstractConfiguration
class, which is the base class
of most configuration implementations provided by this package, per default
returns null if a property is not found, but provides the
method, with which it can be configured to throw a
setThrowExceptionOnMissing()
NoSuchElementException
exception in that case. (Note that getter methods for primitive types in
AbstractConfiguration
always throw an exception for missing
properties because there is no way of overloading the return value.)
With the addProperty()
and setProperty()
methods
new properties can be added to a configuration or the values of properties
can be changed. With clearProperty()
a property can be removed.
Other methods allow to iterate over the contained properties or to create
a subset configuration.
Version: $Id: Configuration.java 449017 2006-09-22 17:27:00Z oheger $
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(String prefix)
Get the list of the keys contained in the configuration that match the
specified prefix.
|
Iterator | getKeys()
Get the list of the keys contained in the configuration. |
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. |
resource.loader = fileis 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.
Parameters: key the key to remove along with corresponding value.
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
Parameters: key The configuration key.
Returns: The associated BigDecimal if key is found and has valid format
Parameters: key The configuration key. defaultValue The default value.
Returns: The associated BigDecimal if key is found and has valid format, default value otherwise.
Parameters: key The configuration key.
Returns: The associated BigInteger if key is found and has valid format
Parameters: key The configuration key. defaultValue The default value.
Returns: The associated BigInteger if key is found and has valid format, default value otherwise.
Parameters: key The configuration key.
Returns: The associated boolean.
Throws: ConversionException is thrown if the key maps to an object that is not a Boolean.
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.
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.
Parameters: key The configuration key.
Returns: The associated byte.
Throws: ConversionException is thrown if the key maps to an object that is not a Byte.
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.
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.
Parameters: key The configuration key.
Returns: The associated double.
Throws: ConversionException is thrown if the key maps to an object that is not a Double.
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.
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.
Parameters: key The configuration key.
Returns: The associated float.
Throws: ConversionException is thrown if the key maps to an object that is not a Float.
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.
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.
Parameters: key The configuration key.
Returns: The associated int.
Throws: ConversionException is thrown if the key maps to an object that is not a Integer.
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.
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.
Parameters: prefix The prefix to test against.
Returns: An Iterator of keys that match the prefix.
See Also: getKeys
remove()
method is specific to
a concrete implementation. It may remove the corresponding
property from the configuration, but this is not guaranteed. In any case
it is no replacement for calling
clearProperty
for this property. So it is
highly recommended to avoid using the iterator's remove()
method.
Returns: An Iterator.
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.
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.
Parameters: key The configuration key.
Returns: The associated long.
Throws: ConversionException is thrown if the key maps to an object that is not a Long.
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.
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.
key=value
. These
strings are splitted at the equals sign, and the key parts will become
keys of the returned Properties
object, the value parts
become values.
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).
Configuration
interface the other get methods (that
return specific data types) will internally make use of this method. On
this level variable substitution is not yet performed. The returned
object is an internal representation of the property value for the passed
in key. It is owned by the Configuration
object. So a caller
should not modify this object. It cannot be guaranteed that this object
will stay constant over time (i.e. further update operations on the
configuration may change its internal state).
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.
Parameters: key The configuration key.
Returns: The associated short.
Throws: ConversionException is thrown if the key maps to an object that is not a Short.
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.
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.
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.
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.
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.
Returns: true
if the configuration contains no property,
false
otherwise.
Parameters: key The key of the property to change value The new value
prefix.number = 1 prefix.string = Apache prefixed.foo = bar prefix = Jakartathe 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.
Returns: a subset configuration
See Also: SubsetConfiguration