public class Hello World extends Http Servlet public

Простейший сервлет public class Hello. World extends Http. Servlet{ public void do. Get(Http. Servlet. Request request, Http. Servlet. Response responser) throws Servlet. Exception, IOException{ response. set. Content. Type(“text/html”); Print. Writer out = response. get. Writer(); out. println(“<HTML>”); out. println(“<HEAD><TITLE>Hello World!</TITLE></HEAD>”); out. println(“<BODY>”); out. println(“<b>Hello World!</b>”); out. println(“</BODY></HTML>”); } }

Настройка web-приложения для работы web. xml: <servlet> <servlet-name>Hello. World</servlet-name> <servlet-class>Hello. World</servlet-class> </servlet> <servlet-mapping> <servlet-name>Hello. World</servlet-name> <url-pattern>/servlet/Hello. World</url-pattern> </servlet-mapping>

Получение информации об окружении сервлета Http. Servlet. Request: get. Protocol() get. Method() get. Path. Info() get. Path. Translated() get. Servlet. Path() get. Real. Path() get. Query. String()

Получение информации о сервере Http. Servlet. Request: get. Server. Name() get. Server. Port() get. Session() Servlet. Context: get. Server. Info() get. Attribute. Names(); get. Attribute(String name)

Получение информации о клиенте Http. Servlet. Request: get. Remote. Host() get. Remote. Addr() get. Auth. Type() get. Remote. User() get. Content. Type() get. Content. Length()

Методы Http. Servlet. Response void send. Error (int status. Code) void send. Redirect(String location) void set. Status (int status. Code) void set. Header(String name, String value)

Переадресация запроса response. send. Redirect(site); = response. set. Status(SC_MOVED_TEMPORARILY); response. set. Header(“Location”, site);

Уведомление об ошибках e. print. Stack. Trace(response. get. Writer()) java. lang. Exception: ошибка! at Hello. World. do. Get(Hello. World. java: 57) at javax. servlet. http. Http. Servlet. service(Http. Servlet. java: 697) at javax. servlet. http. Http. Servlet. service(Http. Servlet. java: 802) at org. apache. catalina. core. Application. Filter. Chain. internal. Do. Filter(Application. Filter. Chain. ja va: 237) at org. apache. catalina. core. Application. Filter. Chain. do. Filter(Application. Filter. Chain. java: 157) at org. apache. catalina. core. Standard. Wrapper. Valve. invoke(Standard. Wrapper. Valve. java: 214 ) at org. apache. catalina. core. Standard. Valve. Context. invoke. Next(Standard. Valve. Context. java: 104) at org. apache. catalina. core. Standard. Pipeline. invoke(Standard. Pipeline. java: 520) at org. apache. catalina. core. Standard. Context. Valve. invoke. Internal(Standard. Context. Valve. ja va: 198) at org. apache. catalina. core. Standard. Context. Valve. invoke(Standard. Context. Valve. java: 152) at org. apache. catalina. core. Standard. Valve. Context. invoke. Next(Standard. Valve. Context. java: 104) at org. apache. catalina. core. Standard. Pipeline. invoke(Standard. Pipeline. java: 520) at

Ведение журнала работы (лога) get. Servlet. Context(). log (String message, Throwable exception) get. Servlet. Context(). log (String message)

Объект Http. Session Http. Servletrequest. get. Session(boolean create) Http. Session. put. Value(String name, Object value) Http. Session. get. Value(String name) Http. Session. get. Value. Names() Http. Session. remove. Value(String name) Http. Session. get. Creation. Time() Http. Session. get. Last. Accessed. Time() Http. Session. invalidate() Http. Session. get. Id() Http. Servlet. Response. encode. URL()