Spring MVC and parsing HTML

Question

I have a controller class as in the following code segment:

@Controller
public class SiteEntryController 
{
    @RequestMapping(value="/index.htm")
    public ModelAndView handleIndex(
      @RequestParam(value="enableStats", required=false) String enableStats) 
    {
     ModelMap map = new ModelMap();

     ...........

     return new ModelAndView("index", map); 
    }
}

and ViewResolver is defined as the following :

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
 p:prefix="/WEB-INF/jsp/" p:suffix=".jsp"/>

What I need to do is, to read/parse content of index.jsp which has only html markup, and return some information about the tags used in the content. I will look for how to view the information that I have gathered, but first, I couldn't figure out how to access the content. I am familiar with java, but totally new to Spring. So my question would be silly one. :) Just for your information, what I couldn't figure out is not how to parse HTML, it is about how to get the file content.

I did this stuff with normal file operations as in the following:

public class Main {

private static HTMLEditorKit.ParserCallback callback;

/**
 * @param args
 */
public static void main(String[] args) {
 try {
  Reader r = new FileReader("D:/WS/TestP/resource/index.htm");
  ParserDelegator parser = new ParserDelegator();
  callback = new Detector();
  parser.parse(r, callback, false);
 } catch (Exception _ex) {
  _ex.printStackTrace();
 }
 HashMap<String, Integer> map = ((Detector) callback).getMap();
 Set<String> keys = map.keySet();
 Iterator<String> it = keys.iterator();
 String key;
 ArrayList<TagFrequency> list = new ArrayList<TagFrequency>();
 TagFrequency tf;
 int i = 0, j = 0;
 while (it.hasNext()) {
  key = it.next();
  i = map.get(key);
  tf = new TagFrequency(key, i);
  if (list.size() == 0)
   list.add(tf);
  else {
   j = 0;
   while (j < list.size() && tf.compareTo(list.get(j)) > 0) {
    j++;
   }
   if (j==list.size())
    list.add(tf);
   else {
    list.add(j, tf);
   }
  }
 }
 for (int ind = list.size(); ind>0 ; ind--) {
  System.out.println(list.get(ind-1).toString());
 }  
}
}

Detector.java:

public class Detector extends HTMLEditorKit.ParserCallback {

    private HashMap<String, Integer> map = new HashMap<String, Integer>();

    public Detector () {
    }

    @Override
    public void handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos) {
     String str = t.toString();
     if (map.get(str) == null) {
      map.put(str, Integer.valueOf(1));
     } else {
      map.put(str, map.get(str) + 1);
     }
    }

    public HashMap<String, Integer> getMap() {
     return map;
    }
}

and TagFrequency.java:

public class TagFrequency {
    private String tag;
    private Integer i;
    public TagFrequency(String tag, Integer i) {
     super();
     this.tag = tag;
     this.i = i;
    }
    public String getTag() {
     return tag;
    }
    public void setTag(String tag) {
     this.tag = tag;
    }
    public Integer getI() {
     return i;
    }
    public void setI(Integer i) {
     this.i = i;
    }
    public String toString() {
     return this.tag + " " + this.i;
    }

    public int compareTo(TagFrequency tf) {
     if (tf.i > this.i)
      return -1;
     else if (tf.i < this.i)
      return 1;
     else
      return (-1)*this.tag.compareToIgnoreCase(tf.tag);
    }
}

Answer 1

You can implement it using a servlet filter that will pass on a servlet response wrapper caching the HTML, and then run your code on it.

A project which uses this technique is SiteMesh, so you can a pick in its code.