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 DocTreeVisitor 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.

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);
      }
   }
Implementation Requirements:

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 with 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 with 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 or 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.
Since:
1.8

  • Constructor Details

    • DocTreeScanner

      public DocTreeScanner()
      Constructs a DocTreeScanner.

  • 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.
      Specified by:
      visitAttribute in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitAuthor in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitComment in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitDeprecated in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitDocComment in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitDocRoot in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitDocType in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitEndElement in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitEntity in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitErroneous in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitHidden in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitIdentifier in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitIndex in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitInheritDoc in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitLink in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitLiteral in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitParam in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitProvides in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitReference in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitReturn in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSee in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSerial in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSerialData in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSerialField in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSince in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning

    • visitSnippet

      public R visitSnippet(SnippetTree node, P p)
      Visits a SnippetTree node.
      Specified by:
      visitSnippet in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning
      Since:
      18

    • visitStartElement

      public R visitStartElement(StartElementTree node, P p)
      Visits a StartElementTree node.
      Specified by:
      visitStartElement in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSummary in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitSystemProperty in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitText in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      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.
      Specified by:
      visitThrows in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitUnknownBlockTag in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitUnknownInlineTag in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitUses in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitValue in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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 VersionTree node.
      Specified by:
      visitVersion in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation scans the children in left to right order.
      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.
      Specified by:
      visitOther in interface DocTreeVisitor<R,P>
      Implementation Requirements:
      This implementation returns null.
      Parameters:
      node - the node being visited
      p - a parameter value
      Returns:
      the result of scanning