import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
@Override
public Void scan(final DocTree tree, Void ignore) {
    if (tree != null) {
        DocTree previous = null;
        for (DocTree current : getCurrentPath()) {
            if (previous != null) {
                final List<DocTree> children = new ArrayList<>();
                current.accept(new DocTreeScanner<Void, Void>() {
                    @Override public Void scan(DocTree node, Void p) {
                        children.add(node);
                        return null;
                    }
                }, null);

                if (!children.contains(previous)) {
                    error("Invalid DocTreePath for: " + tree);
                }
            }

            previous = current;
        }
    }
    return super.scan(tree, ignore);
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
private static List<DocTree> listChildren(@NonNull DocTree t) {
    final List<DocTree> result = new LinkedList<DocTree>();

    t.accept(new DocTreeScanner<Void, Void>() {
        @Override
        public Void scan(DocTree node, Void p) {
            result.add(node);
            return null;
        }
    }, null);

    return result;
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
private DocTree getLastChild(DocTree tree) {
    final DocTree[] last = new DocTree[] {null};

    tree.accept(new DocTreeScanner<Void, Void>() {
        @Override public Void scan(DocTree node, Void p) {
            if (node != null) last[0] = node;
            return null;
        }
    }, null);

    return last[0];
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
private DocTree getLastChild(DocTree tree) {
    final DocTree[] last = new DocTree[] {null};

    tree.accept(new DocTreeScanner<Void, Void>() {
        @Override @DefinedBy(Api.COMPILER_TREE)
        public Void scan(DocTree node, Void p) {
            if (node != null) last[0] = node;
            return null;
        }
    }, null);

    return last[0];
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
private void check() {
    DocCommentTree dc = trees.getDocCommentTree(getCurrentPath());
    if (dc == null)
        return;

    DocTreeScanner<Void, Void> s = new DocTreeScanner<Void, Void>() {
        @Override
        public Void visitErroneous(ErroneousTree tree, Void ignore) {
            messager.printMessage(Diagnostic.Kind.NOTE, tree.getDiagnostic().getMessage(null));
            return null;
        }
    };

    s.scan(dc, null);
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
@Override
void check(TreePath path, Name name) throws Exception {
    JavaFileObject fo = path.getCompilationUnit().getSourceFile();
    final CharSequence cs = fo.getCharContent(true);

    final DCDocComment dc = (DCDocComment) trees.getDocCommentTree(path);
    DCTree t = (DCTree) trees.getDocCommentTree(path);

    DocTreeScanner scanner = new DocTreeScanner<Void,Void>() {
        @Override
        public Void scan(DocTree node, Void ignore) {
            if (node != null) {
                try {
                    String expect = getExpectText(node);
                    long pos = ((DCTree) node).getSourcePosition(dc);
                    String found = getFoundText(cs, (int) pos, expect.length());
                    if (!found.equals(expect)) {
                        System.err.println("expect: " + expect);
                        System.err.println("found:  " + found);
                        error("mismatch");
                    }

                } catch (StringIndexOutOfBoundsException e) {
                    error(node.getClass() + ": " + e.toString());
                        e.printStackTrace();
                }
            }
            return super.scan(node, ignore);
        }
    };

    scanner.scan(t, null);
}
 

import com.sun.source.util.DocTreeScanner; //导入依赖的package包/类
private String render(List<? extends DocTree> trees) {
  StringBuilder buffer = new StringBuilder();
  DocTreeVisitor<Void, Void> visitor = new DocTreeScanner<Void, Void>() {
    @Override
    public Void visitText(TextTree node, Void aVoid) {
      buffer.append(node.getBody());
      return super.visitText(node, aVoid);
    }
  };
  trees.forEach(tree -> tree.accept(visitor, null));
  return buffer.toString();
}