–Form 表单简介 –创建并提交表单 –使用Servlet处理表单
• 读取多个表单
• 读取所有参数名称
–实例• 注册会员 ###############Michael分割线#################–Form 表单简介
• 表单是web程序和用户交互的主要途径之一，例如：搜索引擎、用户登录、注册等操作都离不开表单的使用
• 常用表单元素
–input
» text
» password
» radio
» checkbox
» hidden
» file
» button
» reset
» submit
–select
» option
–textarea• 创建并提交表单
–一个简单的表单（例如：登录），如下所示
–当单击“登录”按钮时表单被提交• 使用Servlet处理表单
–读取单个请求参数
• String user = request.getParameter(“user”);RegisterServlet.javapackage com.michael.servletform;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegisterServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public RegisterServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* 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");
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.println("username:"+username);
out.println("username:"+password);
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 {
doGet(request,response);
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}
}register.html<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>register.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
<form action="/Servlet_Form/servlet/RegisterServlet" method="post">
用户名称：<input type="text" name="username"><br>
用户密码：<input type="password" name="password"><br>
<input type="submit" value="注册">
</body>
</html>web.xml<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="/xml/ns/j2ee"
xmlns:xsi="/2001/XMLSchema-instance"
xsi:schemaLocation="/xml/ns/j2ee
/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>RegisterServlet</servlet-name>
<servlet-class>com.michael.servletform.RegisterServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegisterServlet</servlet-name>
<url-pattern>/servlet/RegisterServlet</url-pattern>
</servlet-mapping>
</web-app>测试
–读取多个表单
• String[] hobby = request.getParameterValues(“hobby”);register.html<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>register.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
<form action="/Servlet_Form/servlet/RegisterServlet" method="post">
用户名称：<input type="text" name="username"><br>
用户密码：<input type="password" name="password"><br>
用户爱好：<input type="checkbox" name="hobby" value="1">游泳
<input type="checkbox" name="hobby" value="2">足球<br>
<input type="submit" value="注册">
</body>
</html>RegisterServlet.javapackage com.michael.servletform;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegisterServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public RegisterServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* 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");
String[] hobby = request.getParameterValues("hobby");
if(hobby!=null&&hobby.length>0){
for(int i=0;i<hobby.length;i++){
System.out.println(hobby[i]);
}
}
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.println("username:"+username);
out.println("password:"+password);
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 {
doGet(request,response);
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}
}测试一下hobby输出到控制台了 ##########Michael分割线################
