org.dmd.util

Class FileUpdateManager

java.lang.Object

org.dmd.util.FileUpdateManager

public class FileUpdateManager
extends Object

The FileUpdateManager is a code generation helper class that will only replace an existing file if the newly generated file is different from a previously generated one. It also tracks the set of files that are generated to a particular output folder and will automatically remove files that are no longer required. This is especially useful when removing files for classes that have been removed from schemas or renamed.

This mechanism is useful when you include dark-matter code generation as part of your build process because it cuts down on the number of files that have to be recompiled; if code hasn't changed, the FileUpdateManager leaves the original file (and its time stamp) intact, so unneeded recompilation is avoided.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FileUpdateManager() Constructs a new FileUpdateManager.

Method Summary

Modifier and Type	Method and Description
void	deleteFiles(boolean f) Delete files for obsolete files defaults to true.
void	fileClosed(ManagedFileWriter mfw) This method is called from the ManagedFileWriter when its close() method is called.
void	fileHeader(String fh) Sets the file header that will be automatically written to your files.
void	generationComplete() This method should be called when a code generation cycle is complete.
void	generationStarting() You should call this method when you are about to start a code generation cycle.
ManagedFileWriter	getWriter(String of, String fn) Use this method to get a BufferedWriter for the file you're generating and close it as normal when you're done.
static FileUpdateManager	instance()
void	reportErrors(PrintStream ps) Sets the stream to which error messages will be dumped.
void	reportProgress(PrintStream ps) Sets the stream to which progress messages will be dumped.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileUpdateManager

protected FileUpdateManager()

Constructs a new FileUpdateManager.

Method Detail

instance

public static FileUpdateManager instance()

Returns:

a handle to the FileUpdateManager.

deleteFiles

public void deleteFiles(boolean f)

Delete files for obsolete files defaults to true. If you only to wish to receive warnings of these files, set this to false.

Parameters:

f -

reportProgress

public void reportProgress(PrintStream ps)

Sets the stream to which progress messages will be dumped.

Parameters:

ps - The print stream.

reportErrors

public void reportErrors(PrintStream ps)

Sets the stream to which error messages will be dumped.

Parameters:

ps - The print stream.

fileHeader

public void fileHeader(String fh)

Sets the file header that will be automatically written to your files.

Parameters:

fh -

generationStarting

public void generationStarting()

You should call this method when you are about to start a code generation cycle.

generationComplete

public void generationComplete()

This method should be called when a code generation cycle is complete. It will check each of the folder where code was generated and verify that all of the .java files in the folder were generated during this code generation run. If it finds .java files in the folder that were not recorded during the generation, they will be deleted.

getWriter

public ManagedFileWriter getWriter(String of,
                                   String fn)
                            throws IOException

Use this method to get a BufferedWriter for the file you're generating and close it as normal when you're done. If the file doesn't yet exist, it will be written straight to your output directory. However, if the file exists, we will write the file to the working folder and perform a comparison with the existing file. If the files are different, we'll replace the existing file, if not, we just leave the existing file alone.

Parameters:

of - The output folder.

fn - The name of the file to be generated.

Returns:

A BufferedWriter derivative that informs the FileUpdateManager when it's closed.

Throws:

IOException

fileClosed

public void fileClosed(ManagedFileWriter mfw)

This method is called from the ManagedFileWriter when its close() method is called. If required, we check the file to see if we need to replace it.

Parameters:

mfw -