Package org.pipservices3.data.persistence

Class FilePersistence<T>

java.lang.Object

org.pipservices3.data.persistence.MemoryPersistence<T>

org.pipservices3.data.persistence.FilePersistence<T>

All Implemented Interfaces:

org.pipservices3.commons.config.IConfigurable, org.pipservices3.commons.refer.IReferenceable, org.pipservices3.commons.run.ICleanable, org.pipservices3.commons.run.IClosable, org.pipservices3.commons.run.IOpenable

public abstract class FilePersistence<T>
extends MemoryPersistence<T>
implements org.pipservices3.commons.config.IConfigurable

Abstract persistence component that stores data in flat files and caches them in memory.

This is the most basic persistence component that is only able to store data items of any type. Specific CRUD operations over the data items must be implemented in child classes by accessing this._items property and calling save() method.

### Configuration parameters ###

• path: path to the file where data is stored

### References ###

• *:logger:*:*:1.0 (optional) ILogger components to pass log messages

### Example ###

 
 class MyJsonFilePersistence extends FilePersistence<MyData> {
   public MyJsonFilePersistence(String path) {
     super(MyData.class, new JsonFilePersister(path));
   }
 
   public MyData getByName(String correlationId, String name) {
     MyData item = find(name); // search method
     ...
     return item;
   } 
 
   public MyData set(String correlatonId, MyData item) {
     this._items = filter(); // filter method
     ...
     this._items.add(item);
     this.save(correlationId);
   }
 
 }
 
 

See Also:

• MemoryPersistence
• JsonFilePersister

Field Summary

Fields

Modifier and Type	Field	Description
protected JsonFilePersister<T>	_persister

Fields inherited from class org.pipservices3.data.persistence.MemoryPersistence

_items, _loader, _lock, _logger, _maxPageSize, _opened, _saver, _type, _typeName

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	FilePersistence(Class<T> type)	Creates a new instance of the persistence.
protected	FilePersistence(Class<T> type, JsonFilePersister<T> persister)	Creates a new instance of the persistence.

Method Summary

Modifier and Type	Method	Description
void	configure(org.pipservices3.commons.config.ConfigParams config)	Configures component by passing configuration parameters.

Methods inherited from class org.pipservices3.data.persistence.MemoryPersistence

clear, close, create, deleteByFilter, getCountByFilter, getListByFilter, getListByFilter, getOneRandom, getPageByFilter, getPageByFilter, isOpen, open, save, setReferences

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

_persister

protected JsonFilePersister<T> _persister

Constructor Details

FilePersistence

protected FilePersistence(Class<T> type)

Creates a new instance of the persistence.

Parameters:

type - the class type

FilePersistence

protected FilePersistence(Class<T> type,
 JsonFilePersister<T> persister)

Creates a new instance of the persistence.

Parameters:

type - the class type

persister - (optional) a persister component that loads and saves data from/to flat file.

Method Details

configure

public void configure(org.pipservices3.commons.config.ConfigParams config)
               throws org.pipservices3.commons.errors.ConfigException

Configures component by passing configuration parameters.

Specified by:

configure in interface org.pipservices3.commons.config.IConfigurable

Overrides:

configure in class MemoryPersistence<T>

Parameters:

config - configuration parameters to be set.

Throws:

org.pipservices3.commons.errors.ConfigException