javax.lang.model.element

Interface ElementVisitor<R,P>

public interface ElementVisitor<R,P>

A visitor for program elements. This is used when the specific type of element is not known at compile time. A visitor instance is passed to the Element.accept(ElementVisitor,P) method of the element, which then calls the specific visitN method appropriate to that specific element.

The additional parameter supplied to visitor methods may or may not be optional, and so the class is free to throw a NullPointerException if null is passed as the additional parameter.

As this interface may be extended to accomodate future language versions, implementators are encouraged to extend one of the appropriate abstract classes rather than implementating this interface. However, this interface should be used as the type for parameters and return values.

Since:
1.6

Method Summary

R
visit(Element element)
A convenience method for use when there is no additional parameter to pass.
R
visit(Element element, P param)
Visits an element.
R
visitExecutable(ExecutableElement element, P param)
Visits an executable element.
R
visitPackage(PackageElement element, P param)
Visits a package element.
R
visitType(TypeElement element, P param)
Visits a type element.
R
visitTypeParameter(TypeParameterElement element, P param)
Visits a type parameter element.
R
visitUnknown(Element element, P param)
Visits an unknown element.
R
visitVariable(VariableElement element, P param)
Visits a variable element.

Method Details

visit

public R visit(Element element)
A convenience method for use when there is no additional parameter to pass. This is equivalent to #visit(element, null).
Parameters:
element - the element to visit.
Returns:
the return value specific to the visitor.

visit

public R visit(Element element,
               P param)
Visits an element.
Parameters:
element - the element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

visitExecutable

public R visitExecutable(ExecutableElement element,
                         P param)
Visits an executable element.
Parameters:
element - the executable element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

visitPackage

public R visitPackage(PackageElement element,
                      P param)
Visits a package element.
Parameters:
element - the package element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

visitType

public R visitType(TypeElement element,
                   P param)
Visits a type element.
Parameters:
element - the type element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

visitTypeParameter

public R visitTypeParameter(TypeParameterElement element,
                            P param)
Visits a type parameter element.
Parameters:
element - the type parameter element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

visitUnknown

public R visitUnknown(Element element,
                      P param)
Visits an unknown element. This method is called if a new type of element is added to the hierarchy which isn't yet handled by the visitor.
Parameters:
element - the element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.
Returns:
the return value specific to the visitor.
Throws:
UnknownElementException - if the implementation chooses to.

visitVariable

public R visitVariable(VariableElement element,
                       P param)
Visits a variable element.
Parameters:
element - the variable element to visit.
param - the additional parameter, specific to the visitor. May be null if permitted by the visitor.

ElementVisitor.java -- A visitor of program elements. Copyright (C) 2012 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.