import ?java.io.IOException;
import ?java.util.ArrayList;
import ?java.util.Random;

import ?javax.servlet.ServletException;
import ?javax.servlet.http.HttpServlet;
import ?javax.servlet.http.HttpServletRequest;
import ?javax.servlet.http.HttpServletResponse;

import ?net.sf.json.JSONSerializer;


public ? class ?TagCloudAction? extends ?HttpServlet? {


???? private ? static ?String?cache? = ? "" ;
???? /**?*/ /**
?????*?
????? */
???? private ? static ? final ? long ?serialVersionUID? = ? - 7031695721764039045L ;

????@Override
???? protected ? void ?doGet(HttpServletRequest?req,?HttpServletResponse?resp)
???????????? throws ?ServletException,?IOException? {
????????resp.setHeader(? " Pragma " ,? " no-cache " ?);
????????resp.addHeader(? " Cache-Control " ,? " must-revalidate " ?);
????????resp.addHeader(? " Cache-Control " ,? " no-cache " ?);
????????resp.addHeader(? " Cache-Control " ,? " no-store " ?);
????????resp.setDateHeader( " Expires " ,? 0 );
????????resp.setContentType( " text/xml " );
????????resp.setCharacterEncoding( " UTF-8 " );
???????? if (cache.isEmpty())
???????? {
????????????cache? = ?getTagCloudJSONString();
????????}
????????resp.getOutputStream().write(cache.getBytes( " UTF-8 " ));
????????resp.flushBuffer();
????}
????
???? private ?String?getTagCloudJSONString()
???? {
????????Category?c? = ? new ?Category( " Name " , " This?is?comments " , 10 );
????????c.setCategoryID( 10 );
???????? // System.out.println(?JSONSerializer.toJSON(c).toString()?);
???????? // System.out.println(?JSONSerializer.toJSON(c).toString(2)?);
????????
????????ArrayList < Category > ?categoriesList? = ? new ?ArrayList < Category > ();
????????Random?r? = ? new ?Random();
????????String[]?tags? = ? new ?String[] {
???????????????? " JAVA " , " Groovy " , " Servlet " , " J2EE " , " JSP " , " J2SE "
????????????????, " JSON " , " AJAX " , " CaiClient " , " .NET " , " C# " , " Perl " ,
???????????????? " Python " , " Rails " , " Ruby " , " Boss " , " Nokia " , " GPhone " , " iPhone "
????????????????, " HiPhone " , " Ericsson " , " Semens " , " Novels " , " 春天 " , " 夏天 " , " 秋天 " , " 冬天 " , " 節日快樂 " ,
???????????????? " 破釜沉舟 " , " 瑞星殺毒 " , " 奶粉事故 "
????????????????, " 奧運會 " , " Grails " , " Google " , " Baidu " , " XiaoNei " ,
???????????????? " 開心網 " , " 校內網 " , " 海內網 " , " 都是垃圾 " , " 薩達姆 " , " PK " , " 網摘 "
????????} ;
???????? int ?len? = ?tags.length - 1 ;
???????? for ?( int ?i? = ? 0 ;?i? < ? 100 ;?i ++ )? {
????????????Category?item? = ? new ?Category(tags[r.nextInt(len)], " This?is?comments?for? " + i,r.nextInt( 100 ));
????????????item.setCategoryID(i);
????????????categoriesList.add(item);
????????}
????????
????????System.err.println(?JSONSerializer.toJSON(categoriesList).toString()?);
???????? // System.err.println(?JSONSerializer.toJSON(categoriesList).toString(2)?);
????????
???????? return ?JSONSerializer.toJSON(categoriesList).toString( 2 );
????}

}

<! DOCTYPE?html?PUBLIC?"-//W3C//DTD?HTML?4.01?Transitional//EN"?"http://www.w3.org/TR/html4/loose.dtd" >
< html >
< head >
< meta? http-equiv ="Content-Type" ?content ="text/html;?charset=UTF-8" >
< title > Tag?Cloud </ title >
< script? type ="text/javascript" ?src ="json2.js" ></ script >
< script? type ="text/javascript" ?src ="tagcloud.js" ></ script >
< link? rel =StyleSheet? type ="text/css" ?href ="tagCloud.css" >
</ head >
< body >
< p > Version.1?use?raw?XMLHttpRequest?to?get?JSON?data?from?a?Servlet. </ p >
< input? id ="btn_getTagCloud1" ?type ="button" ?value ="Get?tag?cloud?style1"
????onclick ="getTagCloud();" ? />
< div? id ="tagcloud" ></ div >

< input? id ="btn_getTagCloud2" ?type ="button" ?value ="Get?tag?cloud?style2"
????onclick ="getTagCloud2();" ? />
< div? id ="tagcloudwithstyle2" ></ div >
</ body >
</ html >