Package com.helger.dao.simple

Class AbstractSimpleDAO

java.lang.Object
com.helger.dao.AbstractDAO
com.helger.dao.simple.AbstractSimpleDAO
All Implemented Interfaces:
com.helger.commons.log.IHasConditionalLogger, IAutoSaveAware, IDAO
@ThreadSafe public abstract class AbstractSimpleDAO extends AbstractDAO
Base class for a simple DAO.
Author:
Philip Helger

  • Constructor Details

    • AbstractSimpleDAO

      protected AbstractSimpleDAO(@Nonnull com.helger.commons.io.relative.IFileRelativeIO aIO, @Nonnull Supplier<String> aFilenameProvider)

  • Method Details

    • getIO

      @Nonnull protected final com.helger.commons.io.relative.IFileRelativeIO getIO()
      Returns:
      The file-relative IO as passed in the constructor. Never null.

    • getFilenameProvider

      @Nonnull public final Supplier<String> 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(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(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(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(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(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(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(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