Using Rhino's Javascript parser, how to get the comments?

问题

I have some javascript files and parse it using Rhino's javascript parser.

but I can't get the comments.

How can I get the comments?

here's a part of my code.

run this code, "comment" variable has null. also, while running "astRoot.toSource();", it shows only javascript code. no comment included. it disappeared!

[java code]

public void parser() {
    AstRoot astRoot = new Parser().parse(this.jsString, this.uri, 1);

    List<AstNode> statList = astRoot.getStatements();
    for(Iterator<AstNode> iter = statList.iterator(); iter.hasNext();) {
        FunctionNode fNode = (FunctionNode)iter.next();

        System.out.println("*** function Name : " + fNode.getName() + ", paramCount : " + fNode.getParamCount() + ", depth : " + fNode.depth());

        AstNode bNode = fNode.getBody();
        Block block = (Block)bNode;
        visitBody(block);
    }

    System.out.println(astRoot.toSource());
    SortedSet<Comment> comment = astRoot.getComments();
    if(comment == null)
        System.out.println("comment is null");
}

回答1:

Configure your CompilerEnvirons and use AstRoot.visitAll(NodeVisitor):

import java.io.*;
import org.mozilla.javascript.CompilerEnvirons;
import org.mozilla.javascript.Parser;
import org.mozilla.javascript.ast.*;

public class PrintNodes {
  public static void main(String[] args) throws IOException {
    class Printer implements NodeVisitor {
      @Override public boolean visit(AstNode node) {
        String indent = "%1$Xs".replace("X", String.valueOf(node.depth() + 1));
        System.out.format(indent, "").println(node.getClass());
        return true;
      }
    }
    String file = "foo.js";
    Reader reader = new FileReader(file);
    try {
      CompilerEnvirons env = new CompilerEnvirons();
      env.setRecordingLocalJsDocComments(true);
      env.setAllowSharpComments(true);
      env.setRecordingComments(true);
      AstRoot node = new Parser(env).parse(reader, file, 1);
      node.visitAll(new Printer());
    } finally {
      reader.close();
    }
  }
}

Java 6; Rhino 1.7R4

来源：https://stackoverflow.com/questions/15658569/using-rhinos-javascript-parser-how-to-get-the-comments