Config Stores

Configuration files are stored in entities called Stores.

The methods that need to be implemented on a store are:

Read is self-explanatory:

public String read(String name) { // Return the contents of the specified configuration. }

Write is slightly trickier:

public String write(String name, String oldContents, String newContents) { // If the old contents match the current stored contents, the new contents will get stored, // and the method returns null indicating success. // If the old contents DO NOT match the current stored contents (i.e. it was modified in some way), // the new contents are NOT stored, and the method returns the current stored contents. // If the old contents are null, then just always write the new contents. }

The update method is called whenever the stored file gets modified externally:

public String update(String name, String newContents) { // Do something with the updated contents. }

Two configuration stores are provided by default:

The store is defined on the Config object via the following setting:

Example:

// Create a config with in-memory storage. Config config = Config.create("MyConfig.cfg").store(ConfigMemoryStore.DEFAULT).build();

The default store used is {@link oaj.config.store.ConfigFileStore#DEFAULT} which defines the execution directory as the file system directory to store and retrieve files.