ea JSP,Servlet a XML

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?e???????a JSP,Servlet ?a? XML

• ?apad???? ?????

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?e??e??µe?a

• ???t?ta 1
• Servlets
• ???t?ta 2 
• JSP ?a? XML
•  ???t?ta 3
• ???s?µa Links
• Industry Support

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To Web Layer t?? J2EE
EJBs
??se?? ded?µ???? ? ????? p????
JSP ?, Servlets
Client
Server-Side Objects
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? a???te?t????? JSPs
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???s? ?p?µa???sµ???? ?e??d??

• ? ???s? ap?µa???sµ???? µe??d?? (remote method
  invocation, RMI) d?µ?????e? efa?µ???? t?? Java,
  p?? µp????? ?a µ???s??? µe ???e? efa?µ???? t??
  Java ep??? se ??a d??t??. ? RMI ep?t??pe? se µ?a
  efa?µ??? ?a ?a?e? µe??d??? ?a? ?a p??spe?a??e?
  µetaß??t?? µ?sa se µ?a ???? efa?µ???, p?? µp??e?
  ?a e?te?e?ta? se d?af??et??? pe??ß?????ta t??
  Java ? se te?e??? d?af??et??? ?e?t???????
  s?st?µata, ?a? ?a pe??? a?t??e?µe?a ap? s??d?se??
  d??t???.

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? RMI

• ? RMI e??a? ??a? p?? ???p??? µ??a??sµ?? ??a
  ep????????a a??µesa se ?ata?eµ?µ??a a?t??e?µe?a
  t?? Java ap? ?t? e??a? µ?a ap?? s??des? socket,
  epe?d? ?? µ??a??sµ?? ?a? ta p??t?????a
  ep????????a? a??µesa se a?t??e?µe?a ??????ta? ?a?
  p??-t?p?p?????ta?. ?p????µe ?a s???µ???s??µe µe
  ??a ???? p????aµµa t?? Java ???s?µ?p????ta? RMI,
  ????? ?a ??e???eta? ?a ????????µe e? t?? p??t????
  se p??? p??t?????? ?a ep????????sete ? µe t?
  t??p?.

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RMI ?a? RPC

• ??a ???? µ??f? ep????????a? a??µesa se
  a?t??e?µe?a ?a?e?ta? RPC (remote procedure call,
  ???s? ap?µa???sµ???? d?ad??as?a?), ?p?? µp????µe
  ?a ?a??s??µe µe??d??? ? ?a e?te??s??µe
  d?ad??as?e? se ???a p?????µµata ep??? se µ?a
  s??des? d??t???.
• ? RMI ?a? RPC ????? p???? ????? s?µe?a, ? ????a
  d?af??? t??? ?µ?? e??a? ?t? ? RPC st???e? µ???
  ???se?? d?ad??as?a? ep??? se ??a ?a??d??, µe ta
  ???sµata ?a pe????? µa?? ? ?a pe?????f??ta? ?at?
  t?t??? t??p? ?ste ?a µp????? ?a a?a?atas?e?ast???
  st? ???? ????. ??t??eta ? RMI pe??? ???????a
  a?t??e?µe?a ep??? st? Internet.

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? ????te?t????? RMI

• ? s??p?? t?? RMI ?ta? ?a e?s?µat?se? ??a
  ?ata?eµ?µ??? µ??t??? a?t??e?µ???? st?? Java, ?a?
  ?a ???e? t?? a????ep?d?as? µe ??a ap?µa???sµ???
  a?t??e?µe?? t?s? e????? ?s? µe ??a t?p???
  a?t??e?µe??.

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T? µp????µe ?a ?????µe µe t?? RMI

• ?a ???s?µ?p????µe ap?µa???sµ??a a?t??e?µe?a
  a???ß?? µe t?? ?d?? t??p? p?? ???s?µ?p????µe
  t?p??? a?t??e?µe?a (?a ta a?a??t??µe se
  µetaß??t??, ?a ta pe???µe sa? ???sµata se
  µe??d??? ??p)
• ?a ?a???µe µe??d??? se ap?µa???sµ??a a?t??e?µe?a
  µe t?? ?d?? t??p? p?? ?????ta? ?? t?p???? ???se??

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??? ?e?t????e?

• ? RMI pe???aµß??e? e?f?e?? µ??a??sµ??? ??a ???s?
  µe??d?? se ap?µa???sµ??a a?t??e?µe?a ? ??a
  p??asµa ????????? a?t??e?µ???? ? tµ?µ?t??
  a?t??e?µ???? µe a?af??? ? µe t?µ?. ?p?s??
  pe???aµß??e? p??s?ete? e?a???se?? ??a ?e???sµ?
  sfa?µ?t?? d??t??? p?? µp??e? ?a s?µßa????? e??
  ???eta? µ?a ap?µa???sµ??? ?e?t?????a.
• ? RMI ??e? a??et? ep?peda ??a ?a ep?t??e? ?????
  a?t??? t??? s??p??? t??, ?a? µ?a ???s? µe??d??
  d?ape??? p???? ap? a?t? ta ep?peda ??a ft?se?
  e?e? p?? ???e?.

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?a ep?peda t?? RMI
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?a ep?peda Stub ?a? s?e?et??

• ?a ep?peda a?t? s?µpe??f????ta? sa?
  ?p??at?stata a?t??e?µe?a se ???e p?e???,
  ap????ß??ta? t?? ap?µa???sµ??? f?s? t?? ???s??
  µe??d?? ap? t?? ???se?? ???p???s??. ?.?. se µ?a
  efa?µ??? pe??t? µp????µe ?a ?a??s??µe
  ap?µa???sµ??e? µe??d??? µe a???ß?? t?? ?d?? t??p?
  p?? ?a???µe t?p???? µe??d???. ?? a?t??e?µe?? stub
  e??a? ??a t?p??? ?p??at?stat? ??a t?
  ap?µa???sµ??? a?t??e?µe??.

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?? ep?ped? ap?µa???sµ???? a?af????

• ???a? t? ep?ped? p?? ?e????eta? t?? s?s?e?as?a
  µ?a? ???s?? µe??d?? ?a? t?? pa?aµ?t???? t?? ?a?
  ep?st??fe? t?µ?? ??a µetaf??? ep??? st? d??t??.

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To ep?ped? µetaf????

• To ep?ped? µetaf???? p?? e??a? ? p?a?µat???
  s??des? d??t??? ap? t? ??a s?st?µa st? ????. ??
  ep?ped? µetaf???? t?? d??t??? ???s?µ?p??e?te
  a?e???t?ta ap? ta ???a d??, ?ts? ?ste ?a µp????µe
  ?a ???s?µ?p???s??µe d?af??et??? e?d? s??d?se??
  socket ??a RMI (TCP/ UDP ? TCP µe ???sµ??a ???a
  p??t?????a, sa? t? SSL).

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?e??e??µe?a ???t?ta? 2

• ??sa??????? ?????e? sta Servlets
• Servlets VS CGIs
• ?e p????? t??p??? µp????µe ?a ??????µe Servlets
• O ?????? ???? e??? Servlet - Servlet API
• ?a???s?as? ?a?ade??µat?? HelloClient
• ?e??t? pa?ade??µat?? epe?e??as?a? F??µa?
• ??? ?a t?????µe ??a servlet
• Servlet Databases
• ?? ???? µp????µe ?a ?????µe µe ta Servlets
• ???e? ????? st? WWW ??a Servlets

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? te???????a Servlet
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??sa??????? ?????e? sta Servlets

• ?? e??a? ??a Servlet?
• ???a? e??t?te? ??d??a Java (bytecode), p??
  t?????? se www servers t?p?? a?t?s?/ap????s?, ?a?
  t??? epe?te????? ?at? ??p??? t??p?.
• ?a Servlets ???s?µ?p?????ta? se efa?µ???? p??
  apa?t??? p??epe?e??as?a, p??? t?? ap?st??? t??
  ap????s?? st?? a?t?t?.
• ?ts? ta servlets e??a? ?a? a?t? ?at? ??p??? t??p?
  CGIs a??? ??aµµ??a se Java, ?p?te ???????µ??? ??a
  ta p?e??e?t?µata p?? p??sf??e? a?t? ? ???ssa.
• ?a Servlets ap?te???? t? server side p??s?p? t??
  Java se a?t??es? µe ta Applets p?? ap?te???? t?
  Client Side p??s?p? t?? Java

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CGI (µ?a? ?a? ta a?af??aµe)

• CGI ( Common Gateway Interface )
• ??a d?as??des? (a?e???t?t? ap? t?? ???ssa
  p????aµµat?sµ??), p?? ep?t??pe? se ??a server ?a
  ?e???? ??a e??te???? process t? ?p??? d??eta?
  pa?aµ?t???? µ?s? environment variables, t?
  command line, ?a? to standard input ?a? ???fe? ta
  ded?µ??a st? Standart Output. ( ?.? a?t?s? ??a
  t?? d??aµ??? d?µ??????a ?a? ap?st??? µ?a?
  ?st?se??da?)
• ?a?ade??µata ???ss?? p????aµµat?sµ?? (scripting
  languages) CGI e??a? Perl, ASP,Visual Basic
  JavaScript Server Site a??? ?a? C, Unix Shell
  ?.t.?

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? d??aµ? t?? Servlet

• 1) ???a? platform independent - Write once Serve
  Everywhere - Portability
• 2) ??µeta??e???ta? p????? t?? Java API, rmi,
  corba, database connectivity.
• ?????? p??s???? 3rd party components.
• 3) ?p?d?t???t?ta ??t??? - ?????? st?? µ??µ?
  µeta?? d?ad?????? ?a?esµ?t??
• 4) ?sf??e?a ??d??a ( Garbage Coollector,
  Exception Handling )
• 5) ??µ??t?ta (?legance) (Object Oriented, Clean
  Code, Modular, Simple )
• 6) E????o integration ???? ?p??es??? ????
  servers
• 7) ?e?t??????? µe t? p??t?????? ???P

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Me p????? t??p??? µp????µe ?a ??????µe Servlets?
(1/3)

• ?a???ta? ta Classes ?ate??e?a?
• ?????ta? compile t? p?? ??t? .java file ?a?
  t?p??et??ta? t? st?? server
• 1 import java.io.
• 2 import javax.servlet.
• 3 import javax.servlet.http.
• 4
• 5 public class HelloClientServlet extends
  HttpServlet
• 6
• 7 protected void doGet(HttpServletRequest req,
• 8 HttpServletResponse res)
• 9 throws ServletException, IOException
• 10
• 11 res.setContentType("text/html")
• 12 PrintWriter out res.getWriter()
• 13 out.println("ltHTMLgtltHEADgtltTITLEgtHello
  Client!lt/TITLEgt"
• 14 "lt/HEADgtltBODYgtHello Client!lt/BODYgtlt/HTMLgt")
• 15 out.close()
• 16
• 17

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Me p????? t??p??? µp????µe ?a ??????µe Servlets?
(2/3)

• Server Site Includes (SSI)
• Me t?? p??s???? t?? HTML ?ag ltSERVLETgt.
• ? Server ???e? p??-epe?e??as?a ???e a??e???
  .shtml p??? t? ste??e? p?s?.
• Ta extensions µp????µe ?a ???s??µe ap? ta
  properties t?? ???e server (jhtml,shtml,..)
• lthtmlgt
• ltheadgt
• lttitlegtEmbedded Servlet Taglt/titlegt
• lt/headgt
• ltbodygt
• ltSERVLET CODE"Servlet1" CODEBASE"http//serverp
  ort/dir"
• initParam1initvalue1 initParam2initvalue2 gt
• ltSERVLETgt
• lt/bodygt
• lt/htmlgt
• request
• Servlet1
• .shtml file
• response

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Me p????? t??p??? µp????µe ?a ??????µe Servlets?
(3/3)

• JavaServer Pages JSPs
• ???s???? Snippets servlet code ?ate??e?a? st??
  .jsp se??de? (Scriptlets).
• ?a??µ???? t??p?? µe ta ASP (Active Server Pages).
  ?pa?te? e?d??? support
• ap? t?? server.
• lthtmlgt
• ltheadgt
• lttitlegtJSP Filelt/titlegt
• lt/headgt
• ltbodygt
• lt if request.getParameter(name) null)
• out.println (You typed nothing)
• else out.println(You typed
  request.getParameter(name))
• gt
• lt/bodygt
• lt/htmlgt
• request
• .jsp file
• response

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To Servlet API 1.GenericServlet

• ??a ta servlets ???p????? t? interface t??? µ?s?
  µ?a? e? t?? d?? p?? ??t? ßas???? ???se??
• GenericServlet (javax.servlet package) - ?e????
  servlets a?e???t?ta p??t???????
• HttpServlet (javax.servlet.http package) - http
  servlets

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To servlet API 2.HttpServlet
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??????p???s? e??? servlet

• public class BookDBServlet ... public void
  init(ServletConfig config) throws
  ServletException // Store the
  ServletConfig object and log the initialization
  super.init(config)
  // Open a database connection to prepare for
  requests try databaseUrl
  getInitParameter("databaseUrl") ... // get user
  and password parameters the same way
  connection DriverManager.getConnection(databaseU
  rl, user, password)
  catch(Exception e)
  throw new UnavailableException (this,
  "Could
  not open a connection to the database")
  ...

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??????ep?d?as? µe t?? pe??t?

• ?ta? ??a servlet d??eta? ??a ???esµa ap? t??
  pe??t? (client), ?aµß??e? d?? a?t??e?µe?a
  (objects)
• - ??a ServletRequest, p?? e?asfa???e? t??
  ep????????a ap? t?? pe??t? p??? t?? server.
• - ??a ServletResponse, p?? e?asfa???e? t??
  ep????????a ap? t? servlet p?s? st?? pe??t?.
• (?a ServletRequest ?a? ServletResponse e??a?
  interfaces ???sµ??a st? javax.servlet package.)
• ?as???? µ???d??
• - doGet
• - doPost

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??a ap?? servlet (Hello Client !)

• ? p?? ??t? class ????e? p????? t? servlet
• public class SimpleServlet extends HttpServlet
• / Handle the HTTP GET method by building a
  simple web page.
• /
• public void doGet (HttpServletRequest request,
• HttpServletResponse response)
• throws ServletException, IOException
• String title HelloClient"
• // set content type and other response header
  fields first
• response.setContentType("text/html")
• // then write the data of the response
• PrintWriter out response.getWriter()
• out.println("ltHTMLgtltHEADgtltTITLEgtHello
  Client!lt/TITLEgt"
• "lt/HEADgtltBODYgtHello Client!lt/BODYgtlt/HTMLgt")
• out.close()

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T? Unload e??? Servlet

• public class BookDBServlet extends
  GenericServlet
• private BookstoreDB books
• ... // the init method
• public void destroy()
• // Allow the database to be garbage collected
• books null

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? ?????? ???? e??? Servlet

• ???e servlet ??e? t?? ?d?? ????? ????
• ? server t? ???e? load ?a? t? a?????p??e?  
• ?? servlet d??eta? µ?d?? ? ?a? pe??ss?te?a client
  requests  
• ? server t? ???e? remove (???sµ???? servers
  e?te???? a?t? t? ß?µa µ??? ?ta? ?????? shut down)
  

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? ?????? ???? t?? Servlet
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??? ?a t?????µe ??a servlet

• ??ad??as?a
• 1) ?a e??atast?s??µe 1 servlet engine (p.?. Suns
  JavaServer). ?e????e? t? JVM
• 2) ?a p??µ??e?t??µe t? Java Servlet API ver 2.0
  to t? ?p??? pe????e? t?? ???se??
  javax.servlet javax.servlet.http
• Note
• 1) O Javaserver p?? ?a p??µ??e?t??µe ta pe????e?
  s??????.
• 2) ?a ??????µe t? servlet class st?? java ?a? ?a
  t? ?????µe Compile
• 3) ?a t?p??et?s??µe t? class se ??a directory t??
  servlet engine (Web directory)
• 4) ?a ?e????s??µe t? servlet engine
• 5) To servlet engine t??a a?tap?????eta? se
  a?t?se?? p?? ?????ta? st? port 8080
• e.g http//ServerName8080/servlets/Helloworld
• ?ote ?p????µe ?a t?????µe ??a servlet ?ate??e?a?
  ap? ??p??a e??a?e?a Java e.g Symantec VisualCafe
  3.0 , p?? ??e? d??? t?? servlet engine .
•  

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Servlets Database Connectivity

• ?a Servlets ?p?? ??a ta a??? p?????µµata Java
  µp????? ?a s??de???? µe ß?se?? ded?µ???? µe t??
  ???s? drivers (Se ???e? p?atf??µe? µe JDBC, se
  Windows JDBC-ODBC bridge)
•  Ta JDBC e??a? database independent. ?? µe a??a??
  2 ??aµµ?? ??d??a µp????µe ?a a??????µe t?? Sybase
  ß?s? µa? se Oracle, ????? a??a?? t?? ?p????p??
  ??d??a
•  ????µe ep????? ?a epe?e??ast??µe st???e?a ap?
  d?af??et???? ?a? a??µ????e?e?? ß?se?? µ?s? t??
  ??d??a.
• ????? p?e????t?µa e??a? ?t? ta Servlets µp?????
  ?a d?at????? Open Database Connections, µe
  ap?t??esµa ?a µp????? p???? requests ?a
  e??p??et????? ap? ??a ???esµa, se a?t??es? µe ta
  CGI.

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?? ???? µp????µe ?a ?????µe µe ta Servlets ? (1/2)

• ?p?????? p????? t??p?? µe t??? ?p????? ??a
  servlet µp??e? ?a ep????????se? µe ??a ????
  servlet
• a) Servlet Chaining ( ?????ta? d?ad????? Post,
  Get )
• ?p????µe ?a a??s?d?s??µe µ?a se??? ap? servlets ,
  µe
• t?? ?d?? t??p? p?? ?a t? ???aµe µe ta CGIs
• Ta µp????se p?,?a e??a? µ?a d?ad????? ?ata????s?
  ded?µ????.

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?? ???? µp????µe ?a ?????µe µe ta Servlets ? (2/2)

• ß) Servlet Interface through a Database ( p? ??a
  ??a Chat Room )
• ?p????µe ?a ?ata?????µe st???e?a ap? ??a servlet
  se µ?a ß?s? ded?µ???? ?p??, µp??e? ?a ta
  a?a?t?se? ??a ???? servlet ta?t?????a ?a? ?a
  d??eta? ? e????a ?t? ep?????????? ta?t?????a.

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?e???????a JSP

• JavaServer Pages

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?e??e??µe?a ???t?ta? 3

• ?? JSP se??de? ?a? ta Servlets
• ? ????? t?? JSPs ?a? t?? Servlets
• ?? JSP se??de?
• ??a pa??de??µa JSP µe t? a?t?st???? Java bean

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?? JSP ?a? ta Servlets

• ???s?µ?p?????
• JSP Servlet Container
• J2EE Container

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O ????? t?? JSP ?a? t?? Servlets

• O? Entry point st?? efa?µ????
• O? a?????ep?d?as? µe t?? ??? ??sµ?(s?????? µ?s?
  HTTP)
• ? Client µp??e? ?a e??a?
• Browser
• Applet
• Desktop application (Java Web Start)
• Wireless Device
• Server application (B2B)

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?? JSP se??de?

• ?? JSP se??de? e??a? textual documents
• p?? pe???????
• ???t?pa ded?µ??a
• ???aµ??? p????f???a
• ?a? ?????? ???s?
• JavaBeans
• Tag Libraries

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??a pa??de??µa JSP se??da? (1/3)

• lt!-- Number Guess Game
• Written by Papadakis Nikos ltnkpap_at_hotmail.comgt,
  
• http//www.nkpap.com
• --gt
• lt_at_ page import "org.nkpap.test.NumberGuessBean"
  gt
• ltjspuseBean id"numguess" class"org.nkpap.test.N
  umberGuessBean" scope"session"/gt
• ltjspsetProperty name"numguess" property""/gt
• lthtmlgt
• ltheadgtlttitlegtNumber Guesslt/titlegtlt/headgt
• ltbody bgcolor"white"gt
• ltfont size4gt
• lt if (numguess.getNamez()null
  numguess.getNamez().equals("")) gt
• ltform methodgetgt
• What's your Name? ltinput typetext nameNamezgt
• ltinput typesubmit value"Submit"gt

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??a pa??de??µa JSP se??da? (2/3)

• lt else gt
• lt if (numguess.getSuccess()) gt
• Congratulations! ltfont color"FF0000"gtltfont
  size"4"gt lt numguess.getNamez() gtlt/fontgt
  lt/fontgt You got it.
• And after just lt numguess.getNumGuesses() gt
  tries.ltpgt
• lt numguess.reset() gt
• Care to lta href"numguess.jsp"gttry againlt/agt?
• lt else if (numguess.getNumGuesses() 0) gt
• Welcome ltfont size"5"gtlt numguess.getNamez()
  gt lt/fontgt to the Number Guess game.ltpgt
• I'm thinking of a number between 1 and 100.ltpgt
• ltform methodgetgt
• What's your guess? ltinput typetext nameguessgt
• ltinput typesubmit value"Submit"gt
• lt/formgt

42
??a pa??de??µa JSP se??da? (3/3)

• lt else gt
• Good guess, but nope. Try ltbgtlt
  numguess.getHint() gtlt/bgt.
• You have made lt numguess.getNumGuesses() gt
  guesses.ltpgt
• I'm thinking of a number between 1 and 100.ltpgt
• ltform methodgetgt
• What's your guess? ltinput typetext nameguessgt
• ltinput typesubmit value"Submit"gt
• lt/formgt
• lt gt
• lt/fontgt
• lt/bodygt
• lt/htmlgt

43
??a pa??de??µa JSP se??da? (t? java bean)

• // Number Guess Game
• package num
• import java.util.
• public class NumberGuessBean
• int answer
• boolean success
• String hint
• int numGuesses
• public NumberGuessBean()
• reset()
• public void setGuess(String guess)
• numGuesses
• int g

• if (g answer)
• success true
• else if (g -1)
• hint "a number next time"
• else if (g lt answer)
• hint "higher"
• else if (g gt answer)
• hint "lower"
• public boolean getSuccess()
• return success
• public String getHint()
• return "" hint

44
?e?? ?ata???e?? t?? a??e???

• ?a a??e?a JSP µp????? ?a ????? e?te t?? ?at?????
  .jsp e?te t?? .jspf ? .jsf (s?????? ??a ta
  fragments)
• To top a??e?? ?a p??pe? ?µ?? ?a f??e? t??
  ?at????? .jsp

45
Combining Data
JSP Page
Client
XML Source
???e? p????
?ML
46
?e??e??µe?a ???t?ta? 4

• Links
• Industry support

47
Links

• JSP home page http//java.sun.com/products/jsp
• Servlet home page http//java.sun.com/products/ser
  vlet
• Java 2 Platform, Standard Edition
  http//java.sun.com/products/jdk/1.3
• Java 2 Platform, Enterprise Edition
  http//java.sun.com/j2ee
• XML in the Java Platform home page
  http//java.sun.com/xml
• JavaBeans technology home page
  http//java.sun.com/beans
• XML home page at W3C http//www.w3.org/XML
• HTML home page at W3C http//www.w3.org/MarkUp
• XML.org home page http//www.xml.org

48
Industry Support