JSPServletLab AssignmentI.docx

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JSPServletLabAssignmentI

1.Writeaservletthatprints"HelloWorld"

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.*;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

publicclassHelloWorldextendsHttpServlet{

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

out.print（"

Helloworld

}

}

XMLCode（web.xml）:

HelloWorld

myPackage.huangcaiwang.HelloWorld

HelloWorld

/HelloWorld

Output:

2.Writeaservletthatknowstowhomit'ssayinghello,ThisservletmustbecalledfromanHTMLpagetakingusernameasinput.（Usebothgetandpostmethod）

HTMLcode:

UserName:

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.*;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

publicclassWhoSayingHelloextendsHttpServlet{

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

Stringname=request.getParameter（"name"）;

out.print（"

"+name+"issayingHello
"）;

out.println（"usingthedoGETmethod

}

publicvoiddoPost（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

Stringname=request.getParameter（"name"）;

out.print（"

"+name+"issayingHello
"）;

out.println（"usingthedoPOSTmethod

}

}

XMLCode（web.xml）:

WhoSayingHello

myPackage.WhoSayingHello

WhoSayingHello

/WhoSayingHello

Output:

Changethecode“method=”get””into“method=”post””inhtml,thenshowtheoutput:

3.Writeaservletthatcountsanddisplaysthenumberoftimesithasbeenaccessedsincethelastserverreboot（Manythreads,oneservletinstance）.

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.*;

importjavax.servlet.ServletConfig;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

publicclassCountsextendsHttpServlet{

staticintcounts=0;

publicvoidinit（ServletConfigconfig）throwsServletException

{

super.init（config）;

}

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

++counts;

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

out.print（"

thispagehasbeenaccessed"+counts+"times

}

}

XMLCode（web.xml）:

Counts

myPackage.huangcaiwang.Counts

Counts

/Counts

Output:

Everytimewhenyourefresh,thecouts’stimespulsone,thenoutput:

4.Writeaservletthatprintsthenameandvalueforallofitsinitparameters.

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.IOException;

importjava.io.PrintWriter;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

publicclassGetInitParametersextendsHttpServlet{

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

java.util.Enumerationparams=this.getServletConfig（）.getInitParameterNames（）;

while（params.hasMoreElements（））{

Stringname=params.nextElement（）.toString（）;

Stringvalue=this.getServletConfig（）.getInitParameter（name）;

out.println（name+"="+value）;

out.println（"
"）;

}

}

}

XMLCode（web.xml）:

GetInitParameters

myPackage.huangcaiwang.GetInitParameters

class

Ecom612

GetInitParameters

/GetInitParameters

Output:

5.Writeaservletthatdisplaysinformationaboutitsserver（TheprocessiscalledSnooping）.

Hints:

-publicStringServletRequest.getServerName（）

publicintServletRequest.getServerPort（）

publicStringServletContext.getServerInfo（）

publicObjectServletContext.getAttribute（Stringname）

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.IOException;

importjava.io.PrintWriter;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

publicclassSoonpingextendsHttpServlet{

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

StringserverName=request.getServerName（）;

intserverPort=request.getServerPort（）;

StringServerInfo=getServletContext（）.getServerInfo（）;

getServletContext（）.setAttribute（"Color","red"）;

Objectattribute=getServletContext（）.getAttribute（"Color"）;

out.print（"informationaboutmyserverareasfollows:

"）;

out.println（"
"）;

out.print（"serverName:

"+serverName）;

out.print（"
"）;

out.print（"serverPort:

"+serverPort）;

out.print（"
"）;

out.print（"ServerInfo:

"+ServerInfo）;

out.print（"
"）;

out.print（"attribute:

"+attribute）;

out.print（"
"）;

}

}

XMLCode（web.xml）:

Soonping

myPackage.huangcaiwang.Soonping

Soonping

/Soonping

Output:

6.Writeaservletthatsnoopstheserver'sservletandJavaversion.

Selveletcode:

packagemyPackage.huangcaiwang;

importjava.io.IOException;

importjava.io.PrintWriter;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importmyPackage.huangcaiwang.VersionDetector;

publicclassSnoopVersionextendsHttpServlet{

publicvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

response.setContentType（"text/html"）;

PrintWriterout=response.getWriter（）;

out.println（"ServletVersion:

"+VersionDetector.getServletVersion（））;

out.println（"
"）;

out.println（"JavaVersion:

"+VersionDetector.getJavaVersion（））;

}

}

JavacodeofVersionDetectorclass:

packagemyPackage.huangcaiwang;

//Copyright（C）2000-2001byJasonHunter.

//Allrightsreserved.Useofthisclassislimited.

//PleaseseetheLICENSEformoreinformation.

/***

*AclasstodeterminethecurrentServletAPIversionnumber,andthe

*currentJDKversionnumber.Itlooksattheavailableclassesand

*variablestomakethedetermination.TheclasscandetectServlet

*APIversionsupto2.2,andJDKversionsupto1.3.

*

*Itcanbeusedlikethis:

*

*StringservletVersion=VersionDetector.getServletVersion（）;
*StringjavaVersion=VersionDetector.getJavaVersion（）;
*@authorJasonHunter,Copyright©2000
*@version1.3,2002/04/22,addeddetectionofJDK1.5andServletAPI2.4
*@version1.2,2001/04/11,addeddetectionofJDK1.4
*@version1.1,2000/09/22,addeddetectionofServletAPI2.3
*@version1.0,2000/02/08
*/
publicclassVersionDetector{
staticStringservletVersion;
staticStringjavaVersion;
/***
*DeterminestheServletAPIversionnumber.
*@returnaStringrepresentationoftheservletversion
*/
publicstaticStringgetServletVersion（）{
if（servletVersion!
=null）{
returnservletVersion;
}
//Determinetheservletversionbylookingatavailableclasses
//andvariables
//javax.servlet.http.HttpSessionwasintroducedinServletAPI2.0
//javax.servlet.RequestDispatcherwasintroducedinServletAPI2.1
//javax.servlet.http.HttpServletResponse.SC_EXPECTATION_FAILEDwas
//introducedinServletAPI2.2
//javax.servlet.FilterisslatedtobeintroducedinServletAPI2.3
//CountupversionsuntilaNoClassDefFoundErrororNoSuchFieldException
//endsthetry
Stringver=null;
try{
ver="1.0";
Class.forName（"javax.servlet.http.HttpSession"）;
ver="2.0";
Class.forName（"javax.servlet.RequestDispatcher"）;
ver="2.1";
Class.forName（"javax.servlet.http.HttpServletResponse"）
.getDeclaredField（"SC_EXPECTATION_FAILED"）;
ver="2.2";
Class.forName（"javax.servlet.Filter"）;
ver="2.3";
Class.forNam