com.helger.photon.basic.app.dao.impl

Class AbstractSimpleDAO

java.lang.Object

com.helger.photon.basic.app.dao.impl.AbstractDAO

com.helger.photon.basic.app.dao.impl.AbstractSimpleDAO

All Implemented Interfaces:

IAutoSaveAware, IChangeable, IDAO

Direct Known Subclasses:

AuditManager, SystemMessageManager, SystemMigrationManager

@ThreadSafe
public abstract class AbstractSimpleDAO
extends AbstractDAO

Base class for a simple DAO.

Author:

Philip Helger

Nested Class Summary

Nested classes/interfaces inherited from interface com.helger.photon.basic.app.dao.IDAO

IDAO.EMode

Field Summary

Fields inherited from class com.helger.photon.basic.app.dao.impl.AbstractDAO

DEFAULT_AUTO_SAVE_ENABLED, m_aRWLock

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSimpleDAO(IDAOIO aDAOIO, IHasFilename aFilenameProvider)
protected	AbstractSimpleDAO(IDAOIO aDAOIO, String sFilename)
protected	AbstractSimpleDAO(IHasFilename aFilenameProvider)
protected	AbstractSimpleDAO(String sFilename)

Method Summary

Modifier and Type	Method and Description
protected void	beforeWriteToFile(String sFilename, File aFile) Optional callback method that is invoked before the file handle gets opened.
protected abstract com.helger.xml.microdom.IMicroDocument	createWriteData() Create the XML document that should be saved to the file.
IDAOIO	getDAOIO()
IHasFilename	getFilenameProvider()
int	getInitCount()
String	getLastFilename()
LocalDateTime	getLastInitDateTime()
LocalDateTime	getLastReadDateTime()
LocalDateTime	getLastWriteDateTime()
int	getReadCount()
protected File	getSafeFile(String sFilename, IDAO.EMode eMode)
int	getWriteCount()
protected com.helger.xml.serialize.write.IXMLWriterSettings	getXMLWriterSettings()
protected void	initialRead() Call this method inside the constructor to read the file contents directly.
protected void	markAsChanged() This method must be called every time something changed in the DAO.
protected void	modifyWriteData(com.helger.xml.microdom.IMicroDocument aDoc) Modify the created document by e.g. adding some comment or digital signature or whatsoever.
protected void	onFilenameChange(String sPreviousFilename, String sNewFilename) Called after a successful write of the file, if the filename is different from the previous filename.
protected com.helger.commons.state.EChange	onInit() Custom initialization routine.
protected abstract com.helger.commons.state.EChange	onRead(com.helger.xml.microdom.IMicroDocument aDoc) Fill the internal structures with from the passed XML document.
String	toString()
protected static void	triggerExceptionHandlersRead(Throwable t, boolean bIsInitialization, File aFile) Trigger the registered custom exception handlers for read errors.
protected static void	triggerExceptionHandlersWrite(Throwable t, String sErrorFilename, com.helger.xml.microdom.IMicroDocument aDoc) Trigger the registered custom exception handlers for read errors.
void	writeToFileOnPendingChanges() In case there are pending changes write them to the file.

Methods inherited from class com.helger.photon.basic.app.dao.impl.AbstractDAO

beginWithoutAutoSave, endWithoutAutoSave, getExceptionHandlersRead, getExceptionHandlersWrite, hasPendingChanges, internalHasPendingChanges, internalIsAutoSaveEnabled, internalSetPendingChanges, isAutoSaveEnabled, isDebugLogging, performWithoutAutoSave, performWithoutAutoSave, performWithoutAutoSaveThrowing, performWithoutAutoSaveThrowing

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSimpleDAO

protected AbstractSimpleDAO(@Nullable
                            String sFilename)

AbstractSimpleDAO

protected AbstractSimpleDAO(@Nonnull
                            IHasFilename aFilenameProvider)

AbstractSimpleDAO

protected AbstractSimpleDAO(@Nonnull
                            IDAOIO aDAOIO,
                            @Nullable
                            String sFilename)

AbstractSimpleDAO

protected AbstractSimpleDAO(@Nonnull
                            IDAOIO aDAOIO,
                            @Nonnull
                            IHasFilename aFilenameProvider)

Method Detail

getDAOIO

@Nonnull
public final IDAOIO getDAOIO()

Returns:

The DAO IO object used by this instance.

getFilenameProvider

@Nonnull
public final IHasFilename getFilenameProvider()

Returns:

The filename provider used internally to build filenames. Never null.

onInit

@Nonnull
 @OverrideOnDemand
protected com.helger.commons.state.EChange onInit()

Custom initialization routine. Called only if the underlying file does not exist yet. This method is only called within a write lock!

Returns:

EChange.CHANGED if something was modified inside this method

onRead

@Nonnull
 @MustBeLocked(value=WRITE)
protected abstract com.helger.commons.state.EChange onRead(@Nonnull
                                                                                                  com.helger.xml.microdom.IMicroDocument aDoc)

Fill the internal structures with from the passed XML document. This method is only called within a write lock!

Parameters:

aDoc - The XML document to read from. Never null.

Returns:

EChange.CHANGED if reading the data changed something in the internal structures that requires a writing.

getSafeFile

@Nonnull
protected final File getSafeFile(@Nonnull
                                           String sFilename,
                                           @Nonnull
                                           IDAO.EMode eMode)
                                    throws DAOException

Throws:

DAOException

triggerExceptionHandlersRead

protected static void triggerExceptionHandlersRead(@Nonnull
                                                   Throwable t,
                                                   boolean bIsInitialization,
                                                   @Nullable
                                                   File aFile)

Trigger the registered custom exception handlers for read errors.

Parameters:

t - Thrown exception. Never null.

bIsInitialization - true if this happened during initialization of a new file, false if it happened during regular reading.

aFile - The file that was read. May be null for in-memory DAOs.

initialRead

@MustBeLocked(value=WRITE)
protected final void initialRead()
                                                      throws DAOException

Call this method inside the constructor to read the file contents directly. This method is write locked!

Throws:

DAOException - in case initialization or reading failed!

onFilenameChange

@OverrideOnDemand
 @MustBeLocked(value=WRITE)
protected void onFilenameChange(@Nullable
                                                                                String sPreviousFilename,
                                                                                @Nonnull
                                                                                String sNewFilename)

Called after a successful write of the file, if the filename is different from the previous filename. This can e.g. be used to clear old data.

Parameters:

sPreviousFilename - The previous filename. May be null.

sNewFilename - The new filename. Never null.

createWriteData

@Nonnull
 @MustBeLocked(value=WRITE)
protected abstract com.helger.xml.microdom.IMicroDocument createWriteData()

Create the XML document that should be saved to the file. This method is only called within a write lock!

Returns:

The non-null document to write to the file.

modifyWriteData

@OverrideOnDemand
 @MustBeLocked(value=WRITE)
protected void modifyWriteData(@Nonnull
                                                                               com.helger.xml.microdom.IMicroDocument aDoc)

Modify the created document by e.g. adding some comment or digital signature or whatsoever.

Parameters:

aDoc - The created non-null document.

beforeWriteToFile

@OverrideOnDemand
 @MustBeLocked(value=WRITE)
protected void beforeWriteToFile(@Nonnull
                                                                                 String sFilename,
                                                                                 @Nonnull
                                                                                 File aFile)

Optional callback method that is invoked before the file handle gets opened. This method can e.g. be used to create backups.

Parameters:

sFilename - The filename provided by the internal filename provider. Never null.

aFile - The resolved file. It is already consistency checked. Never null.

getXMLWriterSettings

@Nonnull
 @OverrideOnDemand
protected com.helger.xml.serialize.write.IXMLWriterSettings getXMLWriterSettings()

Returns:

The IXMLWriterSettings to be used to serialize the data.

getLastFilename

@Nullable
public final String getLastFilename()

Returns:

The filename to which was written last. May be null if no wrote action was performed yet.

triggerExceptionHandlersWrite

protected static void triggerExceptionHandlersWrite(@Nonnull
                                                    Throwable t,
                                                    @Nonnull
                                                    String sErrorFilename,
                                                    @Nullable
                                                    com.helger.xml.microdom.IMicroDocument aDoc)

Trigger the registered custom exception handlers for read errors.

Parameters:

t - Thrown exception. Never null.

sErrorFilename - The filename tried to write to. Never null.

aDoc - The XML content that should be written. May be null if the error occurred in XML creation.

markAsChanged

@MustBeLocked(value=WRITE)
protected final void markAsChanged()

This method must be called every time something changed in the DAO. It triggers the writing to a file if auto-save is active. This method must be called within a write-lock as it is not locked!

writeToFileOnPendingChanges

public final void writeToFileOnPendingChanges()

In case there are pending changes write them to the file. This method is write locked!

getInitCount

@Nonnegative
public int getInitCount()

Returns:

The number of times this DAO was initialized. Always ≥ 0. Usually this field is not persistent and only is valid until the application ends.

getLastInitDateTime

@Nullable
public final LocalDateTime getLastInitDateTime()

Returns:

The last time this DAO was initialized (without error). May be null if it wasn't read before. Usually this field is not persistent and only is valid until the application ends.

getReadCount

@Nonnegative
public int getReadCount()

Returns:

The number of times this DAO was initialized. Always ≥ 0. Usually this field is not persistent and only is valid until the application ends.

getLastReadDateTime

@Nullable
public final LocalDateTime getLastReadDateTime()

Returns:

The last time this DAO was read (without error). May be null if it wasn't read before. Usually this field is not persistent and only is valid until the application ends.

getWriteCount

@Nonnegative
public int getWriteCount()

Returns:

The number of times this DAO was initialized. Always ≥ 0. Usually this field is not persistent and only is valid until the application ends.

getLastWriteDateTime

@Nullable
public final LocalDateTime getLastWriteDateTime()

Returns:

The last time this DAO was written (without error). May be null if it wasn't written before. Usually this field is not persistent and only is valid until the application ends.

toString

public String toString()

Overrides:

toString in class AbstractDAO