Package org.apache.maven.plugin.compiler

Class IncrementalBuildHelper

java.lang.Object

org.apache.maven.plugin.compiler.IncrementalBuildHelper

public class IncrementalBuildHelper
extends Object

Various helper methods to support incremental builds

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CREATED_FILES_LST_FILENAME

Constructor Summary

Constructors

Constructor	Description
IncrementalBuildHelper(String mojoStatusPath, Set<Path> sources, Path directory, Path outputDirectory)

Method Summary

Modifier and Type	Method	Description
void	afterRebuildExecution()	This method collects and stores all information about files changed since the call to beforeRebuildExecution().
void	beforeRebuildExecution()	This method shall get invoked before the actual Mojo task gets triggered, e.g.
Path	getMojoStatusDirectory()	We use a specific status directory for each Mojo execution to store state which is needed during the next build invocation run.
boolean	inputFileTreeChanged(List<String> added, List<String> removed)	Detect whether the list of detected files has changed since the last build.

Methods inherited from class java.lang.Object

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

Field Details

CREATED_FILES_LST_FILENAME

public static final String CREATED_FILES_LST_FILENAME

See Also:

• Constant Field Values

Constructor Details

IncrementalBuildHelper

public IncrementalBuildHelper(String mojoStatusPath,
 Set<Path> sources,
 Path directory,
 Path outputDirectory)

Method Details

getMojoStatusDirectory

public Path getMojoStatusDirectory()
                            throws org.apache.maven.api.plugin.MojoException

We use a specific status directory for each Mojo execution to store state which is needed during the next build invocation run.

Returns:

the directory for storing status information of the current Mojo execution.

Throws:

org.apache.maven.api.plugin.MojoException

inputFileTreeChanged

public boolean inputFileTreeChanged(List<String> added,
 List<String> removed)

Detect whether the list of detected files has changed since the last build. We simply load the list of files for the previous build from a status file and compare it with the new list. Afterwards we store the new list in the status file.

Returns:

true if the set of inputFiles got changed since the last build.

beforeRebuildExecution

public void beforeRebuildExecution()

This method shall get invoked before the actual Mojo task gets triggered, e.g. the actual compile in maven-compiler-plugin.

Attention: This method shall only get invoked if the plugin re-creates all the output.

It first picks up the list of files created in the previous build and delete them. This step is necessary to prevent left-overs. After that we take a 'directory snapshot' (list of all files which exist in the outputDirectory after the clean).

After the actual Mojo task got executed you should invoke the method afterRebuildExecution() to collect the list of files which got changed by this task.

afterRebuildExecution

public void afterRebuildExecution()

This method collects and stores all information about files changed since the call to beforeRebuildExecution().

Attention: This method shall only get invoked if the plugin re-creates all the output.