Module jdk.compiler
Package com.sun.source.util

Class DocTreeScanner<R,​P>

java.lang.Object
com.sun.source.util.DocTreeScanner<R,​P>
All Implemented Interfaces:
DocTreeVisitor<R,​P>
Direct Known Subclasses:
DocTreePathScanner
public class DocTreeScanner<R,​P>
extends Object
implements DocTreeVisitor<R,​P>
A TreeVisitor that visits all the child tree nodes. To visit nodes of a particular type, just override the corresponding visitXYZ method. Inside your method, call super.visitXYZ to visit descendant nodes.

The default implementation of the visitXYZ methods will determine a result as follows:

  • If the node being visited has no children, the result will be null.
  • If the node being visited has one child, the result will be the result of calling scan on that child. The child may be a simple node or itself a list of nodes.
  • If the node being visited has more than one child, the result will be determined by calling scan each child in turn, and then combining the result of each scan after the first with the cumulative result so far, as determined by the reduce(R, R) method. Each child may be either a simple node of a list of nodes. The default behavior of the reduce method is such that the result of the visitXYZ method will be the result of the last child scanned.

Here is an example to count the number of erroneous nodes in a tree: 

   class CountErrors extends DocTreeScanner<Integer,Void> {
      @Override
      public Integer visitErroneous(ErroneousTree node, Void p) {
          return 1;
      }
      @Override
      public Integer reduce(Integer r1, Integer r2) {
          return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
      }
   }

Since:
1.8

  • Constructor Details

  • Method Details

    • scan

      public R scan​(DocTree node, P p)
      Scans a single node.
      Parameters:
      node - the node to be scanned
      p - a parameter value passed to the visit method
      Returns:
      the result value from the visit method

    • scan

      public R scan​(Iterable<? extends DocTree> nodes, P p)
      Scans a sequence of nodes.
      Parameters:
      nodes - the nodes to be scanned
      p - a parameter value to be passed to the visit method for each node
      Returns:
      the combined return value from the visit methods. The values are combined using the reduce method.

    • reduce

      public R reduce​(R r1, R r2)
      Reduces two results into a combined result. The default implementation is to return the first parameter. The general contract of the method is that it may take any action whatsoever.
      Parameters:
      r1 - the first of the values to be combined
      r2 - the second of the values to be combined
      Returns:
      the result of combining the two parameters

    • visitAttribute

      public R visitAttribute​(AttributeTree node, P p)
      Visits an AttributeTree node. This implementation returns null.
      Specified by:
      visitAttribute in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitAuthor

      public R visitAuthor​(AuthorTree node, P p)
      Visits an AuthorTree node. This implementation scans the children in left to right order.
      Specified by:
      visitAuthor in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitComment

      public R visitComment​(CommentTree node, P p)
      Visits a CommentTree node. This implementation returns null.
      Specified by:
      visitComment in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitDeprecated

      public R visitDeprecated​(DeprecatedTree node, P p)
      Visits a DeprecatedTree node. This implementation scans the children in left to right order.
      Specified by:
      visitDeprecated in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitDocComment

      public R visitDocComment​(DocCommentTree node, P p)
      Visits a DocCommentTree node. This implementation scans the children in left to right order.
      Specified by:
      visitDocComment in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitDocRoot

      public R visitDocRoot​(DocRootTree node, P p)
      Visits a DocRootTree node. This implementation returns null.
      Specified by:
      visitDocRoot in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitDocType

      public R visitDocType​(DocTypeTree node, P p)
      Visits a DocTypeTree node. This implementation returns null.
      Specified by:
      visitDocType in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitEndElement

      public R visitEndElement​(EndElementTree node, P p)
      Visits an EndElementTree node. This implementation returns null.
      Specified by:
      visitEndElement in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitEntity

      public R visitEntity​(EntityTree node, P p)
      Visits an EntityTree node. This implementation returns null.
      Specified by:
      visitEntity in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitErroneous

      public R visitErroneous​(ErroneousTree node, P p)
      Visits an ErroneousTree node. This implementation returns null.
      Specified by:
      visitErroneous in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitHidden

      public R visitHidden​(HiddenTree node, P p)
      Visits a HiddenTree node. This implementation scans the children in left to right order.
      Specified by:
      visitHidden in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitIdentifier

      public R visitIdentifier​(IdentifierTree node, P p)
      Visits an IdentifierTree node. This implementation returns null.
      Specified by:
      visitIdentifier in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitIndex

      public R visitIndex​(IndexTree node, P p)
      Visits an IndexTree node. This implementation returns null.
      Specified by:
      visitIndex in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitInheritDoc

      public R visitInheritDoc​(InheritDocTree node, P p)
      Visits an InheritDocTree node. This implementation returns null.
      Specified by:
      visitInheritDoc in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitLink

      public R visitLink​(LinkTree node, P p)
      Visits a LinkTree node. This implementation scans the children in left to right order.
      Specified by:
      visitLink in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitLiteral

      public R visitLiteral​(LiteralTree node, P p)
      Visits an LiteralTree node. This implementation returns null.
      Specified by:
      visitLiteral in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitParam

      public R visitParam​(ParamTree node, P p)
      Visits a ParamTree node. This implementation scans the children in left to right order.
      Specified by:
      visitParam in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitProvides

      public R visitProvides​(ProvidesTree node, P p)
      Visits a ProvidesTree node. This implementation scans the children in left to right order.
      Specified by:
      visitProvides in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitReference

      public R visitReference​(ReferenceTree node, P p)
      Visits a ReferenceTree node. This implementation returns null.
      Specified by:
      visitReference in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitReturn

      public R visitReturn​(ReturnTree node, P p)
      Visits a ReturnTree node. This implementation scans the children in left to right order.
      Specified by:
      visitReturn in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSee

      public R visitSee​(SeeTree node, P p)
      Visits a SeeTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSee in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSerial

      public R visitSerial​(SerialTree node, P p)
      Visits a SerialTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSerial in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSerialData

      public R visitSerialData​(SerialDataTree node, P p)
      Visits a SerialDataTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSerialData in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSerialField

      public R visitSerialField​(SerialFieldTree node, P p)
      Visits a SerialFieldTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSerialField in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSince

      public R visitSince​(SinceTree node, P p)
      Visits a SinceTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSince in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitStartElement

      public R visitStartElement​(StartElementTree node, P p)
      Visits a StartElementTree node. This implementation scans the children in left to right order.
      Specified by:
      visitStartElement in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSummary

      public R visitSummary​(SummaryTree node, P p)
      Visits a SummaryTree node. This implementation scans the children in left to right order.
      Specified by:
      visitSummary in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning
      Since:
      10

    • visitSystemProperty

      public R visitSystemProperty​(SystemPropertyTree node, P p)
      Visits a SystemPropertyTree node. This implementation returns null.
      Specified by:
      visitSystemProperty in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning
      Since:
      12

    • visitText

      public R visitText​(TextTree node, P p)
      Visits a TextTree node. This implementation returns null.
      Specified by:
      visitText in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitThrows

      public R visitThrows​(ThrowsTree node, P p)
      Visits a ThrowsTree node. This implementation scans the children in left to right order.
      Specified by:
      visitThrows in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitUnknownBlockTag

      public R visitUnknownBlockTag​(UnknownBlockTagTree node, P p)
      Visits an UnknownBlockTagTree node. This implementation scans the children in left to right order.
      Specified by:
      visitUnknownBlockTag in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitUnknownInlineTag

      public R visitUnknownInlineTag​(UnknownInlineTagTree node, P p)
      Visits an UnknownInlineTagTree node. This implementation scans the children in left to right order.
      Specified by:
      visitUnknownInlineTag in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitUses

      public R visitUses​(UsesTree node, P p)
      Visits a UsesTree node. This implementation scans the children in left to right order.
      Specified by:
      visitUses in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitValue

      public R visitValue​(ValueTree node, P p)
      Visits a ValueTree node. This implementation scans the children in left to right order.
      Specified by:
      visitValue in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitVersion

      public R visitVersion​(VersionTree node, P p)
      Visits a VersionTreeTree node. This implementation scans the children in left to right order.
      Specified by:
      visitVersion in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitOther

      public R visitOther​(DocTree node, P p)
      Visits an unknown type of DocTree node. This can occur if the set of tags evolves and new kinds of nodes are added to the DocTree hierarchy. This implementation returns null.
      Specified by:
      visitOther in interface DocTreeVisitor<R,​P>
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning