org.apache.archiva.redback.components.registry.Registry Maven / Gradle / Ivy
package org.apache.archiva.redback.components.registry;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.io.File;
import java.util.Collection;
import java.util.List;
import java.util.Properties;
/**
* The Plexus registry is a single source of external configuration for Plexus components and applications.
* It can be used by components to source configuration, knowing that it can be used from within applications
* without the information being hard coded into the component.
*/
public interface Registry
{
/**
* Dump the entire registry to a string, for debugging purposes.
*
* @return the registry contents
*/
String dump();
/**
* Get a string value from the registry. If not found, null is returned.
*
* @param key the key in the registry
* @return the value
*/
String getString( String key );
/**
* Get a string value from the registry. If not found, the default value is used.
*
* @param key the key in the registry
* @param defaultValue the default value
* @return the value
*/
String getString( String key, String defaultValue );
/**
* Set a string value in the registry.
*
* @param key the key in the registry
* @param value the value to set
*/
void setString( String key, String value );
/**
* Get an integer value from the registry. If not found, an exception is thrown.
*
* @param key the key in the registry
* @return the value
* @throws java.util.NoSuchElementException
* if the key is not found
*/
int getInt( String key );
/**
* Get an integer value from the registry. If not found, the default value is used.
*
* @param key the key in the registry
* @param defaultValue the default value
* @return the value
*/
int getInt( String key, int defaultValue );
/**
* Set an integer value in the registry.
*
* @param key the key in the registry
* @param value the value to set
*/
void setInt( String key, int value );
/**
* Get a boolean value from the registry. If not found, an exception is thrown.
*
* @param key the key in the registry
* @return the value
* @throws java.util.NoSuchElementException
* if the key is not found
*/
boolean getBoolean( String key );
/**
* Get a boolean value from the registry. If not found, the default value is used.
*
* @param key the key in the registry
* @param defaultValue the default value
* @return the value
*/
boolean getBoolean( String key, boolean defaultValue );
/**
* Set a boolean value in the registry.
*
* @param key the key in the registry
* @param value the value to set
*/
void setBoolean( String key, boolean value );
/**
* Load configuration from the given classloader resource.
*
* @param resource the location to load the configuration from
* @throws RegistryException if a problem occurred reading the resource to add to the registry
*/
void addConfigurationFromResource( String resource )
throws RegistryException;
/**
* Load configuration from the given classloader resource.
*
* @param resource the location to load the configuration from
* @param prefix the location to add the configuration at in the registry
* @throws RegistryException if a problem occurred reading the resource to add to the registry
*/
void addConfigurationFromResource( String resource, String prefix )
throws RegistryException;
/**
* Load configuration from the given file.
*
* @param file the location to load the configuration from
* @throws RegistryException if a problem occurred reading the resource to add to the registry
*/
void addConfigurationFromFile( File file )
throws RegistryException;
/**
* Load configuration from the given file.
*
* @param file the location to load the configuration from
* @param prefix the location to add the configuration at in the registry
* @throws RegistryException if a problem occurred reading the resource to add to the registry
*/
void addConfigurationFromFile( File file, String prefix )
throws RegistryException;
/**
* Determine if the registry contains any elements.
*
* @return whether the registry contains any elements
*/
boolean isEmpty();
/**
* Get a list of strings at the given key in the registry.
*
* @param key the key to lookup
* @return the list of strings
*/
List getList( String key );
/**
* TODO move to Map which is more generic ?
* Get the properties at the given key in the registry.
*
* @param key the key to lookup
* @return the properties
*/
Properties getProperties( String key );
/**
* Get a subset of the registry, for all keys descended from the given key.
*
* @param key the key to take the subset from
* @return the registry subset
*/
Registry getSubset( String key );
/**
* Get a list of subsets of the registry, for all keys descended from the given key.
*
* @param key the key to take the subsets from
* @return the registry subsets
*/
List getSubsetList( String key );
/**
* Get a subsection of the registry, identified by the given name. If it doesn't exist, null will be
* returned.
*
* @param name registry section name
* @return the registry
*/
Registry getSection( String name );
/**
* Save any changes to the registry since it was loaded.
*
* @throws RegistryException if there was a problem saving the registry
* @throws UnsupportedOperationException if the registry is not writable
*/
void save()
throws RegistryException, UnsupportedOperationException;
/**
* Add a change listener. Note that settings this on the base registry will only detect 'invalidation' events, not
* individual changes. You should retrieve the named sub-registry to listen for changes.
*
* @param listener the listener
* @todo this isn't ideal, so maybe fix combined configuration to re-fire it's events to it's own listeners in the c-c implementation
*/
void addChangeListener( RegistryListener listener );
/**
* Get all the keys in this registry. Keys are only retrieved at a depth of 1.
*
* @return the set of keys
*/
Collection getKeys();
/**
* Remove a keyed element from the registry.
*
* @param key the key to remove
*/
void remove( String key );
/**
* Remove a keyed subset of the registry.
*
* @param key the subset to remove
*/
void removeSubset( String key );
void initialize() throws RegistryException;
}