Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3)

时间:2022-11-23 22:53:07
�C提交表单的方法
• get
• post

�CServlet 生命周期
�C使用Servlet 输出HTML页面
�C获得Servlet初始化参数
�C页面导航
• 请求重定向
�Cresponse.sendRedirect(“url”);

• 请求转发
�Crequest.getRequestDispatcher(“url”).forward(request,response);
• 请求包含
�Crequest.getRequestDispatcher(“url”).include(request,response);
############Michael分割线################
请求重定向 ServletBasic.java package com.michael.servlet;    

import java.io.IOException;    
import java.io.PrintWriter;    
import java.util.Enumeration;    

import javax.servlet.ServletException;    
import javax.servlet.http.HttpServlet;    
import javax.servlet.http.HttpServletRequest;    
import javax.servlet.http.HttpServletResponse;    

public class ServletBasic extends HttpServlet {    

        /**    
         * Constructor of the object.    
         */
    
        public ServletBasic() {    
                super();    
                System.out.println("-----ServletBasic-----");    
        }    

        /**    
         * Destruction of the servlet. <br>    
         */
    
        public void destroy() {    
                super.destroy();    
                System.out.println("-----destroy-----");    
        }    

        /**    
         * The doGet method of the servlet. <br>    
         *    
         * This method is called when a form has its tag value method equals to get.    
         *    
         * @param request the request send by the client to the server    
         * @param response the response send by the server to the client    
         * @throws ServletException if an error occurred    
         * @throws IOException if an error occurred    
         */
    
        public void doGet(HttpServletRequest request, HttpServletResponse response)    
                        throws ServletException, IOException {    
                String username = request.getParameter("username");    
                String password = request.getParameter("password");    
                System.out.println("username="+username);    
                response.sendRedirect("http://redking.blog.51cto.com");    
                /*    
                if(username!=null&&username.equals("redking")){    
                        request.getRequestDispatcher("/successfull.html").forward(request,response);    
                }else{    
                        request.getRequestDispatcher("/failure.html").forward(request,response);    
                }    
                */
    
                /*    
                System.out.println("-----doGet-----");    

                response.setContentType("text/html");    
                PrintWriter out = response.getWriter();    
                out    
                                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");    
                out.println("<HTML>");    
                out.println("    <HEAD><TITLE>A Servlet</TITLE></HEAD>");    
                out.println("    <BODY>");    
                out.print("        This is ");    
                out.print(this.getClass());    
                out.println(", using the GET method");    
                out.println("    </BODY>");    
                out.println("</HTML>");    
                out.flush();    
                out.close();    
        */
        
        }

        /**    
         * The doPost method of the servlet. <br>    
         *    
         * This method is called when a form has its tag value method equals to post.    
         *    
         * @param request the request send by the client to the server    
         * @param response the response send by the server to the client    
         * @throws ServletException if an error occurred    
         * @throws IOException if an error occurred    
         */
    
        public void doPost(HttpServletRequest request, HttpServletResponse response)    
                        throws ServletException, IOException {    
                System.out.println("-----doPost-----");    
                response.setContentType("text/html");    
                PrintWriter out = response.getWriter();    
                out    
                                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");    
                out.println("<HTML>");    
                out.println("    <HEAD><TITLE>A Servlet</TITLE></HEAD>");    
                out.println("    <BODY>");    
                out.print("        This is ");    
                out.print(this.getClass());    
                out.println(", using the POST method");    
                out.println("    </BODY>");    
                out.println("</HTML>");    
                out.flush();    
                out.close();    
        }    

        /**    
         * Initialization of the servlet. <br>    
         *    
         * @throws ServletException if an error occure    
         */
    
        public void init() throws ServletException {    
                /*    
                //第一种方法    
                String driver = this.getServletContext().getInitParameter("driver");    
                String url = this.getServletContext().getInitParameter("url");    
                System.out.println(driver);    
                System.out.println(url);    
                //第二种方法    
                Enumeration enu = this.getServletContext().getInitParameterNames();    
                while(enu.hasMoreElements()){    
                        String name = (String) enu.nextElement();    
                        String value = this.getServletContext().getInitParameter(name);    
                        System.out.println(name+":"+value);    
                }    
                */
    
                String username = this.getInitParameter("username");    
                String password = this.getInitParameter("password");    
                System.out.println(username);    
                System.out.println(password);    
                System.out.println("-----init-----");    
        }    
        /*    
        @Override    
        protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {    
                // TODO Auto-generated method stub    
                System.out.println("-----service-----");    
        }    
        */
    
}
Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) 看下效果 Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) 重定向了 Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) ############Michael分割线################ 请求包含 ServletBasic.java package com.michael.servlet;    

import java.io.IOException;    
import java.io.PrintWriter;    
import java.util.Enumeration;    

import javax.servlet.ServletException;    
import javax.servlet.http.HttpServlet;    
import javax.servlet.http.HttpServletRequest;    
import javax.servlet.http.HttpServletResponse;    

public class ServletBasic extends HttpServlet {    

        /**    
         * Constructor of the object.    
         */
    
        public ServletBasic() {    
                super();    
                System.out.println("-----ServletBasic-----");    
        }    

        /**    
         * Destruction of the servlet. <br>    
         */
    
        public void destroy() {    
                super.destroy();    
                System.out.println("-----destroy-----");    
        }    

        /**    
         * The doGet method of the servlet. <br>    
         *    
         * This method is called when a form has its tag value method equals to get.    
         *    
         * @param request the request send by the client to the server    
         * @param response the response send by the server to the client    
         * @throws ServletException if an error occurred    
         * @throws IOException if an error occurred    
         */
    
        public void doGet(HttpServletRequest request, HttpServletResponse response)    
                        throws ServletException, IOException {    
                String username = request.getParameter("username");    
                String password = request.getParameter("password");    
                System.out.println("username="+username);    
                //请求重定向    
                //response.sendRedirect("http://redking.blog.51cto.com");    
                //请求包含    
                PrintWriter out = response.getWriter();    
                out.println("This is Servlet Page~~~");    
                request.getRequestDispatcher("/successfull.html").include(request,response);    
                /*    
                //请求转发    
                if(username!=null&&username.equals("redking")){    
                        request.getRequestDispatcher("/successfull.html").forward(request,response);    
                }else{    
                        request.getRequestDispatcher("/failure.html").forward(request,response);    
                }    
                */
    
                /*    
                System.out.println("-----doGet-----");    

                response.setContentType("text/html");    
                PrintWriter out = response.getWriter();    
                out    
                                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");    
                out.println("<HTML>");    
                out.println("    <HEAD><TITLE>A Servlet</TITLE></HEAD>");    
                out.println("    <BODY>");    
                out.print("        This is ");    
                out.print(this.getClass());    
                out.println(", using the GET method");    
                out.println("    </BODY>");    
                out.println("</HTML>");    
                out.flush();    
                out.close();    
        */
        
        }

        /**    
         * The doPost method of the servlet. <br>    
         *    
         * This method is called when a form has its tag value method equals to post.    
         *    
         * @param request the request send by the client to the server    
         * @param response the response send by the server to the client    
         * @throws ServletException if an error occurred    
         * @throws IOException if an error occurred    
         */
    
        public void doPost(HttpServletRequest request, HttpServletResponse response)    
                        throws ServletException, IOException {    
                System.out.println("-----doPost-----");    
                response.setContentType("text/html");    
                PrintWriter out = response.getWriter();    
                out    
                                .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");    
                out.println("<HTML>");    
                out.println("    <HEAD><TITLE>A Servlet</TITLE></HEAD>");    
                out.println("    <BODY>");    
                out.print("        This is ");    
                out.print(this.getClass());    
                out.println(", using the POST method");    
                out.println("    </BODY>");    
                out.println("</HTML>");    
                out.flush();    
                out.close();    
        }    

        /**    
         * Initialization of the servlet. <br>    
         *    
         * @throws ServletException if an error occure    
         */
    
        public void init() throws ServletException {    
                /*    
                //第一种方法    
                String driver = this.getServletContext().getInitParameter("driver");    
                String url = this.getServletContext().getInitParameter("url");    
                System.out.println(driver);    
                System.out.println(url);    
                //第二种方法    
                Enumeration enu = this.getServletContext().getInitParameterNames();    
                while(enu.hasMoreElements()){    
                        String name = (String) enu.nextElement();    
                        String value = this.getServletContext().getInitParameter(name);    
                        System.out.println(name+":"+value);    
                }    
                */
    
                String username = this.getInitParameter("username");    
                String password = this.getInitParameter("password");    
                System.out.println(username);    
                System.out.println(password);    
                System.out.println("-----init-----");    
        }    
        /*    
        @Override    
        protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {    
                // TODO Auto-generated method stub    
                System.out.println("-----service-----");    
        }    
        */
    
}
Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) 测试 Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之12.Servlet基础(3) ############Michael分割线################

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