developmentManyaspweb服务器

*DatabaseDrivenWebApplicationClientsApplicationServersincludingwebserversDatabaseServerTraditionalclient-server(2-tierarchitecture):client:userinterfacedatabaseserver:storesdata.
businesslogic:residesonbothThreeormulti-tierarchitecture:Presentationlayer:client,browserBusinesslayer:webserver,handleswebrequestsandactualfunctionalityDatabaselayer:databaseserver,storesdata*Three-TierArchitecture*BenefitsofWebApplicationsStandard&thinclient:webbrowserEasymaintenancebothserverandclientEasyupgradebothserverandclientFastdevelopmentMaturetechnologiesandplatformsSecurityhttps,passwordprotection,firewalltransparentLimitationsCompatibilityofdifferentwebbrowsersLimitedfunctionalities*WebTechnolgiesClient-sideHTMLCSS(CascadingStyleSheets)XML(ExtensibleMarkupLanguage)JavaScriptVBScriptFlashJavaappletServer-sidePHPPERL/CGIASP(ActiveServerPages)&ASP.
NETJSP(JavaServerPages)JavaServletsC++/CDatabaseODBC,JDBCMSSQL,Oracle,DB2,mysql…*WebApplicationOption1:LAMPLAMPLinuxOSApacheWebServerMySQLDatabasePHPscripting(HypertextPreprocessor)AdvantageFreeOpensourceProvedtobeoneofthemostreliablewaysforwebdevelopmentDisadvantageTechsupportHigherHRcost*WebApplicationOption2:MicrosoftMicrosofttechnologiesWindows2003/vistaOSIIS(InternetInformationServer)WebServerSQLDatabaseASP.
NETscripting(ActiveServerPage)AdvantageTechsupportFastdevelopmentLowerHRcostContinuousimprovementonreliabilityandsecurityDisadvantageCommercialsoftwareNotopensourceSecurity,reliabilityandstability*WebApplicationOption3:JavaJavatechnologiesUnix/LinuxOSApache+Tomcat/Websphere/WeblogicWebServerOracle/Sybase/DB2/MysqlDatabaseJSPscripting(JavaServerPage)andServeletAdvantageProvedtobeoneofthemostreliableandsecurewaysforwebdevelopmentManythirdpartysoftwareDisadvantageHighdevelopmentcostHighHRcostFutureunclearHTMLwww.
w3schools.
com**FormsHTMLandformsareusedtobuildfront-endapplicationCGI/ASP/PHP/JSPareusedtobuildtheback-endapplicationAFormATextInputBoxARadioButtonACheckBoxAHiddenVaribleASubmitButton*Apache,MySQLandPHPIntegration*PHPErrorTurnonphperrorreporting:Fordevelopmentserver,veryuseful;forproductionserver,don'tdothat.
php.
inidisplay_errors=Onerror_reporting=E_ALL&~E_NOTICEhttpd.
confphp_flagdisplay_errorsonphp_valueerror_reporting2039*PHPOverviewOpenSourceserver-sidescriptinglanguagedesignedspecificallyfortheweb.
Conceivedin1994,nowusedon+10millionwebsites.
OutputsnotonlyHTMLbutcanoutputXML,images(JPG&PNG),PDFfilesandevenFlashmoviesallgeneratedonthefly.
Canwritethesefilestothefilesystem.
Supportsawide-rangeofdatabases(20+ODBC).
PHPalsohassupportfortalkingtootherservicesusingprotocolssuchasLDAP,IMAP,SNMP,NNTP,POP3,HTTP.
EasylearningcurveSyntaxPerl-andC-likesyntax.
Relativelyeasytolearn.
LargefunctionlibraryEmbeddeddirectlyintoHTMLTheseparationofHTMLdesignandPHPtagsInterpreted,noneedtocompile*PHPTagsSeewww.
w3schools.
comPHPcodemustbesurroundedwithspecialtagsWritetexttothebrowserwiththeechocommandTowriteHello,World!
tothebrowser,includethefollowinginhello.
phpHello,World";>PhpcodecanbeprettymuchanywhereinHTMLdocument.
*PHPVariablesVariablenamescanbeofanylength;canincludeletters,numbersandunderscores;case-sensitiveToassignvaluestovariables:$foo='bar';DataType:String$foo=1;DataType:integer$foo=5.
34;DataType:Double$foo=array("bar","united");DataType:ArrayDataTypesareautomaticallyassignedthoughyoucanforceadatatypebytypecasting.
Forexample:$foo='Hello';$bar=(int)$foo;$barnowequals0Almostallvariablesarelocal.
Globalsinclude$_POSTArray:$names[0]='Helen';$names[1]='Susan';$names[2]='Marc';*PHPOperatorsOperatorsAssignment(e.
g.
Arithmetic(e.
g.
Comparison(e.
g.
Logical(e.
g.
Comments///**/Goodcodewilluseindentsandcomments.
Usefuldebuggingskillputechocommandsinthemiddleofyourcode,toobservetheoutputvalueanddebug,thenjustcommentouttheechocommands.
*1stPHPscriptHelloWorld!
Hello,Worldphp$myvar="HelloWorld";echo$myvar;body>Onserver,saveitase3.
phpin$HOME/.
WWW-orion/,Onclientbrowser,visithttp://orion.
csl.
mtu.
edu/~yourid/e3.
php*ControlStructuresConditionalstructures(e.
g.
if/else)Repetitionstructures(e.
g.
whileloops).
Exampleif/elseif/elsestatement:if($foo==0){echo'Thevariablefooisequalto0';}elseif(($foo>0)&&($fooYouclickedSubmit!
";elseif($_POST["cancel"echo"YouclickedCancel!
";>*PHP-SessionsSessionsstoretheiridentifierinacookieintheclient'sbrowserEverypagethatusessessiondatamustbeproceededbythesession_start()functionSessionvariablesarethensetandretrievedbyaccessingtheglobal$_SESSION[]Savethisexampleassession.
php".
$_SESSION["count"].
"ahref="session.
phpcount=yes">Clickheretocount*DBselectAListofUsersWhoHaveSignedUpForOscarPool'.
$username.
'\n';}mysql_close($dbh);>Saveitasdata.
php*DBupdateDatabaseupdate");>Saveitasupdate.
php*WebProjectDevelopmentHowtodevelopphp/asp/jspwebpageSeparatetheHTMLdesignandphp/asp/jspcodingTheartistsdesignthelookandfeelofthewebpageThecodersinsertphp/asp/jspcodeintoHTMLfilesSeveraloldadvisesUsethestandardsoftwareengineeringprocesstoguidewebprojectdevelopmentEnduserinteractionanduserrequirementanalysisareimportantandsometimecumbersome…Doasmallproject(aprototype)totestdevelopmentstaffanduserreaction.
SeparatedevelopmentplatformandproductionplatformLookforhelponlineandinlocalcommunity