org.everit.props

Interface PropertyManager

public interface PropertyManager

Property Manager allows the programmer to put key-value pairs in a persistent store. Keys should be unique, therefore the user of the library should prefix each key in the way that they do not conflict with keys that come from other modules. The key-value pairs should not be cached on the user side. The implementation should take care of caching in the way that it keeps data consistent even in a clustered environment.

Method Summary

Modifier and Type	Method and Description
void	addProperty(String key, String value) Associates the specified value with the specified key.
String	getProperty(String key) Returns the value of the given key, or null if this Property Manager contains no mapping for the key.
String	removeProperty(String key) Removes the association for a key from this store if it is present.
String	updateProperty(String key, String value) Replaces the value of the given key in the store.

Method Detail

addProperty

void addProperty(String key,
                 String value)

Associates the specified value with the specified key. Cannot add the same key twice, because the keys are unique. If you want to change its value, use the updateProperty(String, String) method.

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

Throws:

NullPointerException - if the key or value parameter is null.

RuntimeException - an excpetion should be thrown if the key already exists.

getProperty

String getProperty(String key)

Returns the value of the given key, or null if this Property Manager contains no mapping for the key.

Parameters:

key - The key whose associated value is to be returned

Returns:

The value of the given key, or null if this Property Manager contains no mapping for the key.

Throws:

NullPointerException - if the key parameter is null.

removeProperty

String removeProperty(String key)

Removes the association for a key from this store if it is present.

Parameters:

key - Key whose mapping is to be removed

Returns:

the value that was stored till now, null if there was no such value.

Throws:

NullPointerException - if the key parameter is null.

updateProperty

String updateProperty(String key,
                      String value)

Replaces the value of the given key in the store.

Parameters:

key - Key with which the specified value is to be associated.

value - Value to be associated with the specified key. Null value is not supported.

Returns:

The previous value of the modified key, or null if there was no associated value of this key.

Throws:

NullPointerException - if the key or value parameter is null.