{"id":6821,"date":"2020-05-10T08:50:00","date_gmt":"2020-05-10T05:50:00","guid":{"rendered":"https:\/\/www.kampuskod.com\/?p=6821"},"modified":"2020-05-26T22:19:07","modified_gmt":"2020-05-26T19:19:07","slug":"java-servlet-nedir-java-dersleri","status":"publish","type":"post","link":"https:\/\/www.kampuskod.com\/yazilim\/java\/java-servlet-nedir-java-dersleri\/","title":{"rendered":"Java Servlet Nedir? – Java Dersleri"},"content":{"rendered":"\n

Java Web teknolojisinin temelini anlamak i\u00e7in Java Servlet kavram\u0131n\u0131 inceleyece\u011fiz. Java Servlet kavram\u0131 Java EE taraf\u0131nda s\u0131k\u00e7a kullan\u0131l\u0131yor. \u00c7\u00fcnk\u00fc projelerin neredeyse tamam\u0131 web platformlar\u0131 \u00fczerinde. Peki, nedir bu Java Servlet?<\/h4>\n\n\n\n

Servlet Nedir?<\/strong><\/h2>\n\n\n\n
Servletler, bir Web veya uygulama sunucusu \u00fczerinde \u00e7al\u0131\u015fan ve bir Web taray\u0131c\u0131s\u0131ndan veya ba\u015fka bir HTTP istemcisinden gelen istekler ile HTTP sunucusu \u00fczerindeki veritabanlar\u0131 veya uygulamalar aras\u0131nda orta bir katman gibi davranan programlard\u0131r.<\/strong> (\u00c7ok karma\u015f\u0131k gelmi\u015f olabilir bu tan\u0131m, \u015fekil ile a\u00e7\u0131klayal\u0131m \ud83d\ude42 )<\/p>\n\n\n\n
$\"\"$ <\/figure><\/div>\n\n\n\n
Servlet, dinamik bir web uygulamas\u0131 olu\u015fturmak i\u00e7in sunucu (server) \u00fczerinde uygulamay\u0131 \u00e7al\u0131\u015ft\u0131ran bir web bile\u015fenidir. Servlet bir Java s\u0131n\u0131f\u0131d\u0131r.<\/p>\n\n\n\n
Servlet Kullanman\u0131n Avantajlar\u0131 Nelerdir?<\/strong><\/h2>\n\n\n\n
Daha iyi bir performans sa\u011flar.<\/li>
Servletler, her istemci (client) iste\u011fini kar\u015f\u0131lamak i\u00e7in ayr\u0131 bir i\u015flem (process) olu\u015fturmaya ihtiya\u00e7 duymaz.<\/li>
Javada yaz\u0131ld\u0131\u011f\u0131 i\u00e7in Servetler platform ba\u011f\u0131ms\u0131zd\u0131r.<\/li>
Sunucu \u00fczerindeki Java g\u00fcvenlik y\u00f6neticisi, bir sunucu makinesindeki kaynaklar\u0131 korumak i\u00e7in bir dizi k\u0131s\u0131tlama uygular. Bu y\u00fczden servletler g\u00fcvenilirdir.<\/li>
Java s\u0131n\u0131f\u0131 k\u00fct\u00fcphaneleri tam fonksiyonelli\u011fi bir servlet taraf\u0131ndan kullan\u0131labilir. Yani database, grafiksel aray\u00fcz (applet) vb. s\u0131n\u0131flar ile ileti\u015fim kurabilir.<\/li><\/ul>\n\n\n\n
Servletlerin Yapabilecekleri<\/strong><\/h2>\n\n\n\n
\u0130stemciler (clients) \/ Taray\u0131c\u0131lar taraf\u0131ndan g\u00f6nderilen a\u00e7\u0131k (explicit) verileri<\/strong> okuyun. Bir web sayfas\u0131 \u00fczerindeki form verileri veya bir aray\u00fcz (applet) \u00fczerinden gelen veriler.<\/li>
\u0130stemciler (clients) \/ Taray\u0131c\u0131lar taraf\u0131ndan g\u00f6nderilen kapal\u0131 (implicit) HTTP istek verilerini<\/strong> okuyun. Bu istekler taray\u0131c\u0131n\u0131n anlad\u0131\u011f\u0131 \u00e7erezleri, medya t\u00fcrlerini ve s\u0131k\u0131\u015ft\u0131rma \u015femalar\u0131n\u0131 i\u00e7erir. <\/li>
Verileri i\u015fleyin ve sonu\u00e7lar\u0131 olu\u015fturun. Bu a\u015famada veritaban\u0131 ile ba\u011flant\u0131 kurman\u0131z gerekebilir.<\/li>
\u0130stemcilere (clients) \/ Taray\u0131c\u0131lara a\u00e7\u0131k veriler g\u00f6nderin. HTML, XML, .gif ve EXCEL gibi<\/li>
\u0130stemcilere (clients) \/ Taray\u0131c\u0131lara kapal\u0131 HTTP yan\u0131tlar\u0131 g\u00f6nderin. (\u00c7erezler (cookies) ve cache paratmeleri gibi)<\/li><\/ul>\n\n\n\n
Servetler, b\u00fcy\u00fck \u00f6l\u00e7ekli geli\u015ftirme projelerini destekleyen Java s\u0131n\u0131f k\u00fct\u00fcphanelerinin geni\u015fletilmi\u015f bir versiyonu olan Java Enterprise Edition’un (Kurumsal S\u00fcr\u00fcm) standart bir par\u00e7as\u0131 olan javax.servlet<\/strong> ve javax.servlet.http<\/strong> paketleri kullan\u0131larak olu\u015fturulabilir.<\/p>\n\n\n\n
\n\n\n\n
$\"Java$ <\/a><\/figure>
\n
Java Programlama Dersleri<\/a><\/p>\n<\/div><\/div>\n\n\n\n
\n\n\n\n
Servlet Ya\u015fam D\u00f6ng\u00fcs\u00fc<\/strong><\/h2>\n\n\n\n
$\"\"$ <\/figure><\/div>\n\n\n\n
Servlet, init() metotu<\/strong> \u00e7a\u011fr\u0131larak ba\u015flat\u0131l\u0131r (initialize<\/em>).<\/li>
Servlet, bir istemcinin iste\u011fini i\u015flemek i\u00e7in service() metotunu<\/strong> \u00e7a\u011f\u0131r\u0131r.<\/li>
Servlet, destroy() metotu <\/strong>\u00e7a\u011fr\u0131larak sonlan\u0131r (terminate<\/em>).<\/li>
Sonunda, servlet Java Sanal Makinesinin (JVM) \u00e7\u00f6p toplay\u0131c\u0131s\u0131 (garbage collector<\/em>) taraf\u0131ndan toplanan \u00e7\u00f6pt\u00fcr.<\/li><\/ul>\n\n\n\ninit() Metotu<\/h3>\n\n\n\n
init() moetotu sadece bir kez \u00e7a\u011fr\u0131l\u0131r. Sadece servlet olu\u015fturuldu\u011funda init() metotu \u00e7a\u011fr\u0131l\u0131r ve daha sonra herhangi bir kullan\u0131c\u0131 istekleri i\u00e7in \u00e7a\u011fr\u0131lmaz.<\/p>\n\n\n\n
Servlet normalde bir kullan\u0131c\u0131 servlet’e kar\u015f\u0131l\u0131k gelen bir URL’i ilk kez \u00e7a\u011f\u0131rd\u0131\u011f\u0131nda olu\u015fturulur ancak, sunucu ilk ba\u015flat\u0131ld\u0131\u011f\u0131nda servlet y\u00fcklenmesini dahi belirtebilirsiniz.<\/p>\n\n\n\n
init() metot imzas\u0131:<\/p>\n\n\n\n
`public void init() throws ServletException {\n \/\/ Initialization code...\n}<\/code><\/pre>\n\n\n\n`
service() Metotu<\/h3>\n\n\n\n
Service metotu, as\u0131l g\u00f6revleri ger\u00e7ekle\u015ftirmek i\u00e7in ana metottur. Servlet konteyneri, istemciden(taray\u0131c\u0131lardan) genlen istekleri kar\u015f\u0131lamak ve istemciye yan\u0131t d\u00f6nmek i\u00e7in service() metotunu \u00e7a\u011f\u0131r\u0131r.<\/p>\n\n\n\n
Service metotu, HTTP istek tipini (GET, POST, PUT, DELETE vb.) kontrol eder ve doGet, doPost, doPut, doDelete gibi metotlar\u0131 uygun \u015fekilde \u00e7a\u011f\u0131r\u0131r.<\/p>\n\n\n\n
service metot imzas\u0131:<\/p>\n\n\n\n
public void service(ServletRequest request, ServletResponse response) \n throws ServletException, IOException {\n}<\/code><\/pre>\n\n\n\ndoGet() Metotu<\/h3>\n\n\n\nBir GET iste\u011fi, normal bir URL iste\u011finden veya tan\u0131mlanm\u0131\u015f metotu olmayan bir HTML formundan kaynaklan\u0131r ve doGet() metotu taraf\u0131ndan kar\u015f\u0131lanmal\u0131d\u0131r.<\/p>\n\n\n\n public void doGet(HttpServletRequest request, HttpServletResponse response)\n throws ServletException, IOException {\n \/\/ Servlet code\n}<\/code><\/pre>\n\n\n\ndoPost() Metotu<\/h3>\n\n\n\nBir POST iste\u011fi, metot olarak POST alan bir HTML formundan kaynaklan\u0131r ve doPost() metotu taraf\u0131ndan kar\u015f\u0131lanmal\u0131d\u0131r.<\/p>\n\n\n\n public void doPost(HttpServletRequest request, HttpServletResponse response)\n throws ServletException, IOException {\n \/\/ Servlet code\n}<\/code><\/pre>\n\n\n\ndestroy() Metotu<\/h3>\n\n\n\nDestroy metotu, servletin ya\u015fam d\u00f6ng\u00fcs\u00fcn\u00fcn en sonunda sadece bir kez \u00e7a\u011fr\u0131l\u0131r. Bu metot, veritaban\u0131 ba\u011flant\u0131lar\u0131n\u0131 kapatmak, arka plandaki threadleri durdurmak vb. i\u015fleri yapmak i\u00e7in servlet’e bir \u015fans verir.<\/p>\n\n\n\n Destroy metotu \u00e7a\u011fr\u0131ld\u0131ktan sonra, servlet nesnesi \u00e7\u00f6p toplama (garbage collection<\/em>) i\u00e7in i\u015faretlenir.<\/strong><\/p>\n\n\n\n destroy metotu tan\u0131mlamas\u0131:<\/p>\n\n\n\n public void destroy() {\n \/\/ Finalization code...\n}<\/code><\/pre>\n\n\n\n \n\n\n\u0130rlanda \u00d6\u011frenci Vizesi i\u00e7in Gerekli Belgeler<\/a><\/li>\n (Solved) Error ‘npm ERR! ERESOLVE unable to resolve dependency tree’ and & How to fix NPM warnings<\/a><\/li>\n Mikroservis Mimarisi Nedir? Monolitik Mimari Nedir? Microservice vs Monolithic<\/a><\/li>\n Metaverse nedir? Metaverse teknolojisi hayat\u0131m\u0131zda neleri de\u011fi\u015ftirecek?<\/a><\/li>\n Keycloak Kullanarak G\u00fcvenli Java Spring Boot REST API Uygulamas\u0131<\/a><\/li>\n<\/ul>\n\n\n \n\n\n\nYararland\u0131\u011f\u0131m Kaynaklar<\/p>\n\n\n\nhttps:\/\/www.tutorialspoint.com\/servlets\/index.htm<\/a><\/p>\n\n\n\n https:\/\/docs.oracle.com\/javaee\/7\/api\/javax\/servlet\/Servlet.html<\/a><\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Java Web teknolojisinin temelini anlamak i\u00e7in Java Servlet kavram\u0131n\u0131 inceleyece\u011fiz. Java Servlet kavram\u0131 Java EE taraf\u0131nda s\u0131k\u00e7a kullan\u0131l\u0131yor. \u00c7\u00fcnk\u00fc projelerin neredeyse tamam\u0131 web platformlar\u0131 \u00fczerinde. Peki, nedir bu Java Servlet? Servlet Nedir? Servletler, bir Web veya uygulama sunucusu \u00fczerinde \u00e7al\u0131\u015fan ve bir Web taray\u0131c\u0131s\u0131ndan veya ba\u015fka bir HTTP istemcisinden gelen istekler ile HTTP sunucusu \u00fczerindeki […]<\/p>\n","protected":false},"author":4,"featured_media":6866,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"tdm_status":"","tdm_grid_status":""},"categories":[3414],"tags":[420,3435,3678,3423,3675,3677,417,3415,3676],"_links":{"self":[{"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/posts\/6821"}],"collection":[{"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/comments?post=6821"}],"version-history":[{"count":18,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/posts\/6821\/revisions"}],"predecessor-version":[{"id":7464,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/posts\/6821\/revisions\/7464"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/media\/6866"}],"wp:attachment":[{"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/media?parent=6821"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/categories?post=6821"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kampuskod.com\/wp-json\/wp\/v2\/tags?post=6821"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Servlet Ya\u015fam D\u00f6ng\u00fcs\u00fc<\/strong><\/h2>\n\n\n\n<\/figure><\/div>\n\n\n\n