1.1使用Servlet处理表单提交的请求
创建并通过注解配置名为MyServlet的Servlet类,此类继承HttpServlet类并重写了dopost()方法,用于 处理浏览器的请求:
package yuan; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.PrintWriter; @WebServlet("/MyServlet") public class MyServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public MyServlet() { super(); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); String name=request.getParameter("name"); PrintWriter writer=response.getWriter(); if(name!=null) { writer.write("hello"+name+"!"); writer.flush(); writer.close(); } } }
说明:从HttpServletResponse对象中获取的输出流,在完成业务逻辑处理后应刷新缓冲区的数据后关闭输出流对象,以及时释放资源.
创建名为index.jsp的页面,作为程序的主页面,在其中编写一个表单,用于向Servlet提交请求。
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> <form action="MyServlet" method="post"> <p>请输入您的姓名:<input type="text" name="name"></p> <p><input type="submit" value="提交"/></p> </form> </body> </html>
运行结果:
------------------------------------------------------------------------------------
单击“提交”按钮后出现的效果
1.2使用servlet实现页面转发:
创建名称为ForwardServlet.java的类文件,该类继承了HttpServlet类,在该servlet的doGet()方法中调用RequestDispatcher接口的forward()方法向页面转发到main.jsp页面。下面就是ForwardServlet类的具体代码(servlet):
package com.wgh; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.RequestDispatcher; /** * Servlet implementation class FordwardServlet */ @WebServlet("/FordwardServlet") public class FordwardServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public FordwardServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { RequestDispatcher requestDispatcher=request.getRequestDispatcher("main.jsp"); requestDispatcher.forward(request,response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }
main.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>主界面</title> </head> <body> 欢迎访问明日科技网站!——main.jsp </body> </html>
运行结果;
1.3在Servlet中获取当前副武器的路径:
SurePath.java:
package com.wgh; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet实现类SurePath */ @WebServlet("/SurePath") public class SurePath extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public SurePath() { super(); } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html; charset=UTF-8"); ServletContext context = this.getServletContext(); PrintWriter out = response.getWriter(); out.print("获取当前服务器的真实路径:" + context.getRealPath("") + ""); } }
web.xml:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>7.2</display-name> <welcome-file-list> <welcome-file>SurePath</welcome-file> </welcome-file-list> </web-app>
运行结果: