• 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-----");
}
*/
}
看下效果
重定向了
############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-----");
}
*/
}
测试
############Michael分割线################
本文出自 “王乾De技术博客” 博客，谢绝转载！