Package org.aspectj.org.eclipse.jdt.core.compiler

Class CompilationParticipant

java.lang.Object

org.aspectj.org.eclipse.jdt.core.compiler.CompilationParticipant

public abstract class CompilationParticipant
extends Object

A compilation participant is notified of events occurring during the compilation process. The compilation process not only involves generating .class files (i.e. building), it also involves cleaning the output directory, reconciling a working copy, etc. So the notified events are the result of a build action, a clean action, a reconcile operation (for a working copy), etc.

Code that participates in the build should in general be implemented with a separate Builder, rather than a CompilationParticipant. It is only necessary to use a CompilationParticipant if the build step needs to interact with the Java build, for instance by creating additional Java source files that must themselves in turn be compiled.

Clients wishing to participate in the compilation process must subclass this class, and implement isActive(IJavaProject), aboutToBuild(IJavaProject), reconcile(ReconcileContext), etc.

If the "requires" attribute is not used for participant definition, there will be no specific order in which potential multiple compilation participants are called. If they have to be called in a specific order, the attribute "requires" can be set on the extension point entries.

This class is intended to be subclassed by clients.

Since:

3.2

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NEEDS_FULL_BUILD
static final int	READY_FOR_BUILD

Constructor Summary

Constructors

Constructor	Description
CompilationParticipant()

Method Summary

Modifier and Type	Method	Description
int	aboutToBuild(IJavaProject project)	Notifies this participant that a build is about to start and provides it the opportunity to create missing source folders for generated source files.
void	buildFinished(IJavaProject project)	Notifies this participant that a build has finished for the project.
void	buildStarting(BuildContext[] files, boolean isBatch)	Notifies this participant that a compile operation is about to start and provides it the opportunity to generate source files based on the source files about to be compiled.
void	cleanStarting(IJavaProject project)	Notifies this participant that a clean is about to start and provides it the opportunity to delete generated source files.
boolean	isActive(IJavaProject project)	Returns whether this participant is active for a given project.
boolean	isAnnotationProcessor()	Returns whether this participant is interested in Annotations.
boolean	isPostProcessor()	Returns whether this participant is interested in post processing of generated bytecode.
Optional<byte[]>	postProcess(BuildContext file, ByteArrayInputStream bytes)	Notifies this participant about a finished class compilation.
void	processAnnotations(BuildContext[] files)	Notifies this participant that a compile operation has found source files using Annotations.
void	reconcile(ReconcileContext context)	Notifies this participant that a reconcile operation is happening.

Methods inherited from class java.lang.Object

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

Field Details

READY_FOR_BUILD

public static final int READY_FOR_BUILD

See Also:

• Constant Field Values

NEEDS_FULL_BUILD

public static final int NEEDS_FULL_BUILD

See Also:

• Constant Field Values

Constructor Details

CompilationParticipant

public CompilationParticipant()

Method Details

aboutToBuild

public int aboutToBuild(IJavaProject project)

Notifies this participant that a build is about to start and provides it the opportunity to create missing source folders for generated source files. Additional source folders should be marked as optional so the project can be built when the folders do not exist. Only sent to participants interested in the project.

Default is to return READY_FOR_BUILD.

Parameters:

project - the project about to build

Returns:

READY_FOR_BUILD or NEEDS_FULL_BUILD

See Also:

• buildFinished(IJavaProject project)

buildFinished

public void buildFinished(IJavaProject project)

Notifies this participant that a build has finished for the project. This will be sent, even if buildStarting() was not sent when no source files needed to be compiled or the build failed. Only sent to participants interested in the project.

Parameters:

project - the project about to build

Since:

3.4

buildStarting

public void buildStarting(BuildContext[] files,
 boolean isBatch)

Notifies this participant that a compile operation is about to start and provides it the opportunity to generate source files based on the source files about to be compiled. When isBatchBuild is true, then files contains all source files in the project. Only sent to participants interested in the current build project.

Parameters:

files - is an array of BuildContext

isBatch - identifies when the build is a batch build

cleanStarting

public void cleanStarting(IJavaProject project)

Notifies this participant that a clean is about to start and provides it the opportunity to delete generated source files. Only sent to participants interested in the project.

Parameters:

project - the project about to be cleaned

isActive

public boolean isActive(IJavaProject project)

Returns whether this participant is active for a given project.

Default is to return false.

For efficiency, participants that are not interested in the given project should return false for that project.

Note: In special cases, the project may be closed and not exist. Participants typically return false when the underlying project is closed. I.e. when the following check returns false:

        javaProject.getProject().isOpen();
 

Parameters:

project - the project to participate in

Returns:

whether this participant is active for a given project

isAnnotationProcessor

public boolean isAnnotationProcessor()

Returns whether this participant is interested in Annotations.

Returning true enables the callback processAnnotations(BuildContext[]), where this participant can influence build results.

Default is to return false.

Returns:

whether this participant is interested in Annotations

processAnnotations

public void processAnnotations(BuildContext[] files)

Notifies this participant that a compile operation has found source files using Annotations. Only sent to participants interested in the current build project that answer true to isAnnotationProcessor(). Each BuildContext was informed whether its source file currently hasAnnotations().

Parameters:

files - is an array of BuildContext

isPostProcessor

public boolean isPostProcessor()

Returns whether this participant is interested in post processing of generated bytecode.

Returning true enables the callback postProcess(BuildContext,ByteArrayInputStream), where this participant can influence produced class file bytes.

Default is to return false.

Returns:

whether this participant is interested in post processing

Since:

3.34

postProcess

public Optional<byte[]> postProcess(BuildContext file,
 ByteArrayInputStream bytes)

Notifies this participant about a finished class compilation. This notification occurs right before the compiled class is written out to disk. This allows to perform arbitrary byte code manipulation on the generated class.

Only sent to participants that answer true to isPostProcessor().

• If additional dependencies to other classes are introduced by the modified class, these dependencies have to be recorded by calling BuildContext.recordDependencies(String[]).
• In case problems occur, they can be reported using BuildContext.recordNewProblems(CategorizedProblem[]).
• No other API's to record build state changes are supported during post-processing.

Note: the received class data could have already been transformed by another compilation participant. If the compilation participants have to be called in a specific order, the attribute "requires" can be used in the participant contribution entry.

Parameters:

file - context of the generated class

bytes - byte representation of the generated class

Returns:

Optional containing byte array representing the modified class or empty Optional if no modification was applied. Default implementation returns empty Optional.

Since:

3.34

reconcile

public void reconcile(ReconcileContext context)

Notifies this participant that a reconcile operation is happening. The participant can act on this reconcile operation by using the given context. Other participant can then see the result of this participation on this context.

Note that a participant should not modify the buffer of the working copy that is being reconciled.

Default is to do nothing.

Parameters:

context - the reconcile context to act on