求大神指点这段代码什么意思

package org.owasp.webgoat.plugin;

import org.apache.ecs.Element;
import org.apache.ecs.ElementContainer;
import org.apache.ecs.StringElement;
import org.apache.ecs.html.BR;
import org.apache.ecs.html.Input;
import org.owasp.webgoat.lessons.Category;
import org.owasp.webgoat.lessons.LessonAdapter;
import org.owasp.webgoat.session.ECSFactory;
import org.owasp.webgoat.session.WebSession;

import java.util.ArrayList;
import java.util.List;

/**

*
*

This file is part of WebGoat, an Open Web Application Security Project
utility. For details, please see http://www.owasp.org/ *
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version. *
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details. *
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA. *
Getting Source ============== *
Source for this application is maintained at https://github.com/WebGoat/WebGoat, a repository
for free software projects. *
For details, please see http://webgoat.github.io *
@author Bruce Mayhew WebGoat
@created October 28, 2003
*/
public class HttpBasics extends LessonAdapter {
private final static String PERSON = "person";
/**
- Description of the Method *
- @param s Description of the Parameter
- @return Description of the Return Value
  */
  protected Element createContent(WebSession s) {
  ElementContainer ec = new ElementContainer();
  StringBuffer person = null;
  try {
  ec.addElement(new BR());
  ec.addElement(new StringElement(getLabelManager().get("EnterYourName") + ": "));
```
person = new StringBuffer(s.getParser().getStringParameter(PERSON, ""));
person.reverse();

Input input = new Input(Input.TEXT, PERSON, person.toString());
ec.addElement(input);

Element b = ECSFactory.makeButton(getLabelManager().get("Go!"));
ec.addElement(b);
```
  } catch (Exception e) {
  s.setMessage("Error generating " + this.getClass().getName());
  e.printStackTrace();
  }
  if (!person.toString().equals("") && getLessonTracker(s).getNumVisits() > 3) {
  makeSuccess(s);
  }
  return (ec);
  }
/**
- Gets the hints attribute of the HelloScreen object *
- @return The hints value
  */
  public List getHints(WebSession s) {
  List hints = new ArrayList();
  hints.add("Type in your name and press 'go'");
  hints.add("Turn on Show Parameters or other features");
  hints.add("Try to intercept the request with OWASP ZAP");
  hints.add("Press the Show Lesson Plan button to view a lesson summary");
  hints.add("Press the Show Solution button to view a lesson solution");
  return hints;
  }
/**
- Gets the ranking attribute of the HelloScreen object *
- @return The ranking value */ private final static Integer DEFAULT_RANKING = new Integer(10);
protected Integer getDefaultRanking() {
return DEFAULT_RANKING;
}
protected Category getDefaultCategory() {
return Category.GENERAL;
}
/**
- Gets the title attribute of the HelloScreen object *
- @return The title value */ public String getTitle() { return ("Http Basics"); } }

createContent方法传入一个参数s 是WebSession类型
//通过webSession获取参数解析器，并通过解析器获取（Gets the named parameter value as a String, with a default.）获取一个参数，如果获取不到默认为空字符串.
person = new StringBuffer(s.getParser().getStringParameter(PERSON, ""));
//反转字符串
person.reverse();
//创建一个Input标签，把刚才的值赋给这个Input
Input input = new Input(Input.TEXT, PERSON, person.toString());
ec.addElement(input);
//创建按钮
Element b = ECSFactory.makeButton(getLabelManager().get("Go!"));
ec.addElement(b);

大致是这个样子，望采纳