Class CheckBase

java.lang.Object

org.revapi.java.spi.CheckBase

All Implemented Interfaces:

org.revapi.configuration.Configurable, Check

public abstract class CheckBase
extends Object
implements Check

A basic implementation of the Check interface. This class easies the matching of the visit*() methods and their corresponding visitEnd() by keeping track of the "depth" individual calls (see the recursive nature of the call order).

This class also contains a couple of utility methods for checking the accessibility of elements, etc.

Since:

0.1

Author:

Lukas Krejci

See Also:

• pushActive(JavaElement, JavaElement, Object...)
• popIfActive()

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	CheckBase.ActiveElements<T extends JavaElement>	Represents the elements that have been pushed onto the active elements stack.

Nested classes/interfaces inherited from interface org.revapi.java.spi.Check

Check.Type

Constructor Summary

Constructors

Constructor	Description
CheckBase()

Method Summary

Modifier and Type	Method	Description
protected org.revapi.Difference	createDifference(Code code, LinkedHashMap<String,String> attachments)
protected org.revapi.Difference	createDifferenceWithExplicitParams(Code code, LinkedHashMap<String,String> attachments, String... params)
protected List<org.revapi.Difference>	doEnd()
protected List<org.revapi.Difference>	doVisitAnnotation(JavaAnnotationElement oldAnnotation, JavaAnnotationElement newAnnotation)
protected void	doVisitClass(JavaTypeElement oldType, JavaTypeElement newType)
protected void	doVisitField(JavaFieldElement oldField, JavaFieldElement newField)
protected void	doVisitMethod(JavaMethodElement oldMethod, JavaMethodElement newMethod)
protected void	doVisitMethodParameter(JavaMethodParameterElement oldParameter, JavaMethodParameterElement newParameter)
org.revapi.AnalysisContext	getAnalysisContext()
String	getExtensionId()
Reader	getJSONSchema()
TypeEnvironment	getNewTypeEnvironment()
TypeEnvironment	getOldTypeEnvironment()
void	initialize(org.revapi.AnalysisContext analysisContext)
boolean	isAccessible(JavaModelElement e)	This method checks that the provided element and all its parent elements are accessible (public or protected).
boolean	isBothAccessible(JavaModelElement a, JavaModelElement b)	Checks whether both provided elements are public or protected.
boolean	isBothPrivate(JavaModelElement a, JavaModelElement b)	Checks whether both provided elements are (package) private.
boolean	isDescendingOnNonExisting()	The default implementation returns false, because that is the right decision most of the time.
boolean	isMissing(Element e)	The element is deemed missing if its type kind (TypeMirror.getKind()) is TypeKind.ERROR.
protected CheckBase.ActiveElements<?>	peekLastActive()
protected <T extends JavaElement> CheckBase.ActiveElements<T>	popIfActive()	Pops the top of the stack of active elements if the current position in the call stack corresponds to the one that pushed the active elements.
protected <T extends JavaElement> CheckBase.ActiveElements<T>	popIfActive(Class<T> type)	Pops the top of the stack of the active elements if the current position in the call stack corresponds to the one that pushed the active elements.
protected final <T extends JavaElement> void	pushActive(T oldElement, T newElement, Object... context)	If called in one of the doVisit*() methods, this method will push the elements along with some contextual data onto an internal stack.
void	setNewTypeEnvironment(TypeEnvironment env)	The environment containing the new version of the classes.
void	setOldTypeEnvironment(TypeEnvironment env)	The environment containing the old version of the classes.
final List<org.revapi.Difference>	visitAnnotation(JavaAnnotationElement oldAnnotation, JavaAnnotationElement newAnnotation)	Please override the doVisitAnnotation(JavaAnnotationElement, JavaAnnotationElement) instead.
final void	visitClass(JavaTypeElement oldType, JavaTypeElement newType)	Please override the doVisitClass(JavaTypeElement, JavaTypeElement)
final List<org.revapi.Difference>	visitEnd()	Please override the doEnd() method instead.
final void	visitField(JavaFieldElement oldField, JavaFieldElement newField)	Please override the doVisitField(JavaFieldElement, JavaFieldElement) instead.
final void	visitMethod(JavaMethodElement oldMethod, JavaMethodElement newMethod)	Please override the doVisitMethod(JavaMethodElement, JavaMethodElement) instead.
final void	visitMethodParameter(JavaMethodParameterElement oldParameter, JavaMethodParameterElement newParameter)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.revapi.java.spi.Check

getInterest

Constructor Details

CheckBase

public CheckBase()

Method Details

isDescendingOnNonExisting

public boolean isDescendingOnNonExisting()

The default implementation returns false, because that is the right decision most of the time.

Specified by:

isDescendingOnNonExisting in interface Check

Returns:

false

isBothPrivate

public boolean isBothPrivate(@Nullable
 JavaModelElement a,
 @Nullable
 JavaModelElement b)

Checks whether both provided elements are (package) private. If one of them is null, the fact cannot be determined and therefore this method would return false.

Parameters:

a - first element

b - second element

Returns:

true if both elements are not null and are private or package private

isBothAccessible

public boolean isBothAccessible(@Nullable
 JavaModelElement a,
 @Nullable
 JavaModelElement b)

Checks whether both provided elements are public or protected. If one at least one of them is null, the method returns false, because the accessibility cannot be truthfully detected in that case.

Parameters:

a - first element

b - second element

Returns:

true if both elements are not null and accessible (i.e. public or protected)

isAccessible

public boolean isAccessible(@Nonnull
 JavaModelElement e)

This method checks that the provided element and all its parent elements are accessible (public or protected). Additionally, if the provided element is a type, it must be in API or, if it is not a type, its nearest enclosing type must be in API.

Parameters:

e - the element to check

Returns:

true if the provided element is accessible and in API, false otherwise.

isMissing

public boolean isMissing(@Nonnull
 Element e)

The element is deemed missing if its type kind (TypeMirror.getKind()) is TypeKind.ERROR.

Parameters:

e - the element

Returns:

true if the element is missing, false otherwise

createDifference

@Nonnull
protected org.revapi.Difference createDifference(@Nonnull
 Code code,
 LinkedHashMap<String,String> attachments)

createDifferenceWithExplicitParams

@Nonnull
protected org.revapi.Difference createDifferenceWithExplicitParams(@Nonnull
 Code code,
 LinkedHashMap<String,String> attachments,
 String... params)

getOldTypeEnvironment

@Nonnull
public TypeEnvironment getOldTypeEnvironment()

getNewTypeEnvironment

@Nonnull
public TypeEnvironment getNewTypeEnvironment()

getAnalysisContext

@Nonnull
public org.revapi.AnalysisContext getAnalysisContext()

getExtensionId

@Nullable
public String getExtensionId()

Specified by:

getExtensionId in interface org.revapi.configuration.Configurable

getJSONSchema

@Nullable
public Reader getJSONSchema()

Specified by:

getJSONSchema in interface org.revapi.configuration.Configurable

initialize

public void initialize(@Nonnull
 org.revapi.AnalysisContext analysisContext)

Specified by:

initialize in interface org.revapi.configuration.Configurable

setOldTypeEnvironment

public void setOldTypeEnvironment(@Nonnull
 TypeEnvironment env)

Description copied from interface: Check

The environment containing the old version of the classes. This can be used to reason about the classes when doing the checks.

Called once after the check has been instantiated.

Specified by:

setOldTypeEnvironment in interface Check

Parameters:

env - the environment to obtain the helper objects using which one can navigate and examine types

setNewTypeEnvironment

public void setNewTypeEnvironment(@Nonnull
 TypeEnvironment env)

Description copied from interface: Check

The environment containing the new version of the classes. This can be used to reason about the classes when doing the checks.

Called once after the check has been instantiated.

Specified by:

setNewTypeEnvironment in interface Check

Parameters:

env - the environment to obtain the helper objects using which one can navigate and examine types

visitEnd

@Nullable
public final List<org.revapi.Difference> visitEnd()

Please override the doEnd() method instead.

Specified by:

visitEnd in interface Check

Returns:

the list of found differences between corresponding elements or null if no differences found (null is considered equivalent to returning an empty collection).

See Also:

• Check.visitEnd()

doEnd

@Nullable
protected List<org.revapi.Difference> doEnd()

visitClass

public final void visitClass(@Nullable
 JavaTypeElement oldType,
 @Nullable
 JavaTypeElement newType)

Please override the doVisitClass(JavaTypeElement, JavaTypeElement)

Specified by:

visitClass in interface Check

See Also:

• Check.visitClass(JavaTypeElement, JavaTypeElement)

doVisitClass

protected void doVisitClass(@Nullable
 JavaTypeElement oldType,
 @Nullable
 JavaTypeElement newType)

visitMethod

public final void visitMethod(@Nullable
 JavaMethodElement oldMethod,
 @Nullable
 JavaMethodElement newMethod)

Please override the doVisitMethod(JavaMethodElement, JavaMethodElement) instead.

Specified by:

visitMethod in interface Check

See Also:

• Check.visitMethod(JavaMethodElement, JavaMethodElement)

doVisitMethod

protected void doVisitMethod(@Nullable
 JavaMethodElement oldMethod,
 @Nullable
 JavaMethodElement newMethod)

visitMethodParameter

public final void visitMethodParameter(@Nullable
 JavaMethodParameterElement oldParameter,
 @Nullable
 JavaMethodParameterElement newParameter)

Specified by:

visitMethodParameter in interface Check

doVisitMethodParameter

protected void doVisitMethodParameter(@Nullable
 JavaMethodParameterElement oldParameter,
 @Nullable
 JavaMethodParameterElement newParameter)

visitField

public final void visitField(@Nullable
 JavaFieldElement oldField,
 @Nullable
 JavaFieldElement newField)

Please override the doVisitField(JavaFieldElement, JavaFieldElement) instead.

Specified by:

visitField in interface Check

See Also:

• Check.visitField(JavaFieldElement, JavaFieldElement)

doVisitField

protected void doVisitField(@Nullable
 JavaFieldElement oldField,
 @Nullable
 JavaFieldElement newField)

visitAnnotation

@Nullable
public final List<org.revapi.Difference> visitAnnotation(@Nullable
 JavaAnnotationElement oldAnnotation,
 @Nullable
 JavaAnnotationElement newAnnotation)

Please override the doVisitAnnotation(JavaAnnotationElement, JavaAnnotationElement) instead.

Specified by:

visitAnnotation in interface Check

Parameters:

oldAnnotation - the annotation in the old API

newAnnotation - the annotation in the new API

Returns:

the list of differences between the two annotations

See Also:

• Check.visitAnnotation(JavaAnnotationElement, JavaAnnotationElement)

doVisitAnnotation

@Nullable
protected List<org.revapi.Difference> doVisitAnnotation(@Nullable
 JavaAnnotationElement oldAnnotation,
 @Nullable
 JavaAnnotationElement newAnnotation)

pushActive

protected final <T extends JavaElement> void pushActive(@Nullable
 T oldElement,
 @Nullable
 T newElement,
 Object... context)

If called in one of the doVisit*() methods, this method will push the elements along with some contextual data onto an internal stack.

You can then retrieve the contents on the top of the stack in your doEnd() override by calling the popIfActive() method.

Type Parameters:

T - the type of the elements

Parameters:

oldElement - the old API element

newElement - the new API element

context - optional contextual data

popIfActive

@Nullable
protected <T extends JavaElement>
CheckBase.ActiveElements<T> popIfActive()

Pops the top of the stack of active elements if the current position in the call stack corresponds to the one that pushed the active elements.

This method does not do any type checks, so take care to retrieve the elements with the same types used to push to them onto the stack.

Type Parameters:

T - the type of the elements

Returns:

the active elements or null if the current call stack did not push any active elements onto the stack

popIfActive

@Nullable
protected <T extends JavaElement>
CheckBase.ActiveElements<T> popIfActive(Class<T> type)

Pops the top of the stack of the active elements if the current position in the call stack corresponds to the one that pushed the active elements.

The stack is always popped but a non-null value is returned only if there was an active element AND the element is assignable to the provided type.

This method is a more type-safe variant of popIfActive() and should be used in situations where more than 1 type can be expected in the doEnd() implementation.

Parameters:

type - the expected type of the elements

Returns:

non-null if there were active elements and the elements have the provided type

peekLastActive

@Nullable
protected CheckBase.ActiveElements<?> peekLastActive()

Returns:

the last activation. This can be called at any point and can refer to any of the enclosing elements of the currently processed element pair, depending on how this check activated them.