JsonFilePersister<T>

Implements: IConfigurable, ILoader, ISaver

Description

The JsonFilePersister class allows you to create persistence components that load and save data from/to a flat file

Configuration parameters

• path: path to the file where the data is stored

Constructors

Creates a new instance of the JSON file persistence component.

public JsonFilePersister(Class type, String path)

• path: String - (optional) path to the file where the data is stored.

Properties

path

Gets the file path where the data is stored.

protected String _path;

• returns: String - file path where the data is stored.

Sets the file path where data is stored.

public void setPath(String value)

• value: String - file path where data is stored.

Instance methods

configure

Configures the component by passing its configuration parameters.

public void configure(ConfigParams config) throws ConfigException

• config: ConfigParams - configuration parameters to be set.

load

Loads data items from an external JSON file.

public List load(IContext context) throws ApplicationException

• context: IContext - (optional) a context to trace execution through a call chain.
• returns: List - loaded items

save

Saves given data items to an external JSON file.

public void save(IContext context, List entities) throws ApplicationException

• context: IContext - (optional) a context to trace execution through a call chain.
• entities: List - list if data items to save

Examples

{@code
  JsonFilePersister persister = new JsonFilePersister(MyData.class, "./data/data.json");
 
  ArrayList<String> list = new ArrayList<String>() {{
     add("A");
     add("B");
     add("C");
  }};
  persister.save("123", list);
  ...
  persister.load("123", items);
  System.out.println(items); // Result: ["A", "B", "C"]
  }