Jva Servlet 的简单教程。不定时更新……
Servlet 根接口public interface Servlet{ServletConfig getServletConfig(); service(ServletRequest req, ServletResponse res) throws ServletException, IOException;public void destroy(); // servlet卸载时调用。}
Servlet HelloWorldimport javax.servlet.*;import javax.servlet.http.*;import java.io.*;// 一般来说，一个URL代表一个servletpublic calss ServletsRule extends HttpServlet{int i = 0;public void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException{res.setContentType(“text/html”);PrintWriter out = res.getWriter();out.print(“<HEAD><TITLE>”);out.print(“A server-side strategy”);out.print(“</TITLE></HEAD><BODY>”);out.print(“<H1>Servlets Rule! ” + i++);out.print(“</H1></BODY>”);out.close();}}
Servlet 表单处理javax.servlet.*;import javax.servlet.http.*;import java.io.*;import java.util.*;public calss EchoForm extends HttpServlet{public void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException{res.setContentType(“text/html”);PrintWriter out = res.getWriter();Enumeration flds = req.getParameterNames();if(!flds.hasMoreElements()){// 如果表单内没有数据，我们为了测试，香港服务器租用，就在下面加入了一个表单数据项。out.print(“<html>”);out.print(“<form method=\”POST\”” + ” action=\”EchoForm\”>”);for(int i = 0; i < 10; i++){out.print(“…”);out.print(“…”);}else{// 如果表单内有数据，out.print(“<H1>Your form contained:</H1>”);while(flds.hasMoreElements()){String field = (String)flds.nextElement();String value = req.getParameter(field);out.print(field + ” = ” + value + “<br />”);}}out.close();}}}
Servlet 线程安全// 使用synchronized子句达到线程安全的目的。import javax.servlet.*;import javax.servlet.http.*;import java.io.*;public class ThreadServlet extends HttpServlet{in i;public void service(HttpServletResponse res, HttpServletRequest req){res.setContentType(“text/html”);PrintWriter out = res.getWriter();synchronized(this){try{Thread.currentThread().sleep(5000);}catch(InterruptedException e){System.err.println(“Interrupted”);}}out.print(“<H1>Finished ” + i++ + “</H1>”);out.close();}}
Servlet Session处理// Session。import javax.servlet.*;import javax.servlet.http.*;import java.io.*;import java.util.*;public class SessionPeek extends HttpServlet{in i;public void service(HttpServletResponse res, HttpServletRequest req){HttpSession session = req.getSession(); //res.setContentType(“text/html”);PrintWriter out = res.getWriter();Integer ival = (Integer)session.getAttribute(“SessionPeek.cntr”, ival);// …session.setAttribute(“SessionPeek.cntr”, ival.intValue() + 1)// … Enumeration sesNames = session.getAttributeNames();while(sesNames.hasMoreElements()){String name = sesNames.nextElement().toString();Object value = session.getAttribute(name);/…}session.getId();session.isNew();session.getCreationTime();session.getLastAccessedTime();sssion.getMaxInactiveInterval();req.getRequestedSessionId();req.isRequestedSessionIdFromCookie();req.isRequestedSessionIdFromURL();req.isRequestedSessionIdValid();out.close();}}
，美国空间，香港虚拟主机经受雨，面对另一个轮回。
