org.apache.juneau.config.store

Class ConfigStore

java.lang.Object

org.apache.juneau.Context

org.apache.juneau.config.store.ConfigStore

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ConfigClasspathStore, ConfigFileStore, ConfigMemoryStore

@ConfigurableContext
public abstract class ConfigStore
extends Context
implements Closeable

Represents a storage location for configuration files.

Content stores require two methods to be implemented:

• read(String) - Retrieve a config file.
• write(String,String,String) - ConfigStore a config file.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ConfigStore(PropertyStore ps) Constructor.

Method Summary

Modifier and Type	Method and Description
SessionArgs	createDefaultSessionArgs() Unused.
Session	createSession(SessionArgs args) Unused.
abstract boolean	exists(String name) Checks whether the configuration with the specified name exists in this store.
ConfigMap	getMap(String name) Returns a map file containing the parsed contents of a configuration.
abstract String	read(String name) Returns the contents of the configuration file.
ConfigStore	register(String name, ConfigStoreListener l) Registers a new listener on this store.
protected String	resolveName(String name) Subclasses can override this method to convert config names to internal forms.
ObjectMap	toMap() Returns the properties defined on this bean context as a simple map for debugging purposes.
ConfigStore	unregister(String name, ConfigStoreListener l) Unregisters a listener from this store.
ConfigStore	update(String name, String... contentLines) Convenience method for updating the contents of a file with lines.
ConfigStore	update(String name, String contents) Called when the physical contents of a config file have changed.
abstract String	write(String name, String expectedContents, String newContents) Saves the contents of the configuration file if the underlying storage hasn't been modified.

Methods inherited from class org.apache.juneau.Context

builder, createSession, equals, getArrayProperty, getArrayProperty, getBooleanProperty, getCdlProperty, getClassArrayProperty, getClassArrayProperty, getClassArrayProperty, getClassListProperty, getClassListProperty, getClassMapProperty, getClassMapProperty, getClassProperty, getClassSetProperty, getClassSetProperty, getInstanceArrayProperty, getInstanceArrayProperty, getInstanceArrayProperty, getInstanceProperty, getInstanceProperty, getInstanceProperty, getIntegerProperty, getListProperty, getListProperty, getLongProperty, getMapProperty, getProperty, getProperty, getPropertyKeys, getPropertyStore, getSetProperty, getSetProperty, getStringProperty, getStringPropertyWithNone, hashCode, identityCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.io.Closeable

close

Constructor Detail

ConfigStore

protected ConfigStore(PropertyStore ps)

Constructor.

Parameters:

ps - The settings for this content store.

Method Detail

read

public abstract String read(String name)
                     throws IOException

Returns the contents of the configuration file.

Parameters:

name - The config file name.

Returns:

The contents of the configuration file.
A blank string if the config does not exist.
Never null.

Throws:

IOException - Thrown by underlying stream.

write

public abstract String write(String name,
                             String expectedContents,
                             String newContents)
                      throws IOException

Saves the contents of the configuration file if the underlying storage hasn't been modified.

Parameters:

name - The config file name.

expectedContents - The expected contents of the file.

newContents - The new contents.

Returns:

If null, then we successfully stored the contents of the file.
Otherwise the contents of the file have changed and we return the new contents of the file.

Throws:

IOException - Thrown by underlying stream.

exists

public abstract boolean exists(String name)

Checks whether the configuration with the specified name exists in this store.

Parameters:

name - The config name.

Returns:

true if the configuration with the specified name exists in this store.

register

public ConfigStore register(String name,
                            ConfigStoreListener l)

Registers a new listener on this store.

Parameters:

name - The configuration name to listen for.

l - The new listener.

Returns:

This object (for method chaining).

unregister

public ConfigStore unregister(String name,
                              ConfigStoreListener l)

Unregisters a listener from this store.

Parameters:

name - The configuration name to listen for.

l - The listener to unregister.

Returns:

This object (for method chaining).

getMap

public ConfigMap getMap(String name)
                 throws IOException

Returns a map file containing the parsed contents of a configuration.

Parameters:

name - The configuration name.

Returns:

The parsed configuration.
Never null.

Throws:

IOException - Thrown by underlying stream.

update

public ConfigStore update(String name,
                          String contents)

Called when the physical contents of a config file have changed.

Triggers calls to ConfigStoreListener.onChange(String) on all registered listeners.

Parameters:

name - The config name (e.g. the filename without the extension).

contents - The new contents.

Returns:

This object (for method chaining).

update

public ConfigStore update(String name,
                          String... contentLines)

Convenience method for updating the contents of a file with lines.

Parameters:

name - The config name (e.g. the filename without the extension).

contentLines - The new contents.

Returns:

This object (for method chaining).

resolveName

protected String resolveName(String name)

Subclasses can override this method to convert config names to internal forms.

For example, the ConfigFileStore class can take in both "MyConfig" and "MyConfig.cfg" as names that both resolve to "MyConfig.cfg".

Parameters:

name - The name to resolve.

Returns:

The resolved name.

createSession

public final Session createSession(SessionArgs args)

Unused.

Specified by:

createSession in class Context

Parameters:

args - The session arguments.

Returns:

A new session object.

createDefaultSessionArgs

public final SessionArgs createDefaultSessionArgs()

Unused.

Specified by:

createDefaultSessionArgs in class Context

Returns:

A SessionArgs object, possibly a read-only reusable instance.

toMap

public ObjectMap toMap()

Description copied from class: Context

Returns the properties defined on this bean context as a simple map for debugging purposes.

Overrides:

toMap in class Context

Returns:

A new map containing the properties defined on this context.