JavaWeb实现表单提交的示例详解

2024-04-02 19:55

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register.html

<!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=UTF-8">
<title>register.html</title>
</head>
<body>
	<center><h1>注册表单</h1></center>
	<center>
		<form action="register" method="get">
			用户名:<input type="text" name="username"/><br/>
			密码:<input type="password" name="pwd"/><br/>
			
			 请选择感兴趣的研究方向：
              <label for="01">人工智能</label>
              <input type="checkbox" name="interest" value="AI" id="01" />
              <label for="02">机器学习</label>
              <input type="checkbox" name="interest" value="ML" id="02" />
              <label for="03">自动驾驶</label>
              <input type="checkbox" name="interest" value="AutoDrive" id="03" />
              <label for="04">网络安全</label>
              <input type="checkbox" name="interest" value="Network" id="04" />
              <br/>&nbsp;<input type="submit" name="smt" value="提交"/>
		</form>
	</center>
</body>
</html>

RegisterServlet.java

package request;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
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 RegisterServlet extends HttpServlet{

	//调出doGet方法
	protected void doGet(HttpServletRequest req,HttpServletResponse res)
			throws ServletException,IOException {
		//使用req接收请求参数
		String strName=req.getParameter("username");
		//处理中文乱发问题
		byte[] bs=strName.getBytes("iso8859-1");
		String name=new String(bs,"utf-8");
		System.out.println(name);
	}
	//调出doPost方法
	protected void doPost(HttpServletRequest req,HttpServletResponse res)
			throws ServletException,IOException {
		//设置请求参数中的编码
		req.setCharacterEncoding("utf-8");
		//使用req接收请求参数
		String strName=req.getParameter("username");
		System.out.println("strName");
	}
	//调出service方法
	protected void service(HttpServletRequest request,HttpServletResponse response) 
			throws ServletException,IOException{
		PrintWriter pw=response.getWriter();
		System.out.println("注册。。。");
		//1.获取浏览器端发送请求的完整路径；
		StringBuffer sbuf=request.getRequestURL();
		pw.println("url:"+sbuf);
		//System.out.println(sbuf);
		//2.获取资源名部分-请求路径中8080后的地址;
		String uri=request.getRequestURI();
		pw.println("uri:"+uri); 
		//3.获取请求路径中参数;
		String qs=request.getQueryString();
		pw.println("qs:"+qs);
		//4.获取请求路径中的ip地址;
		String ip=request.getRemoteAddr();
		pw.println("ip:"+ip);//ip=127.0.0.1
		//5.获取浏览器发送请求的方式(get请求、post请求)
		//在浏览器端，浏览器地址栏回车、超链接、表单的默认方式都是get请求方式
		//在浏览器端，表单设置method="post"的方式提交是post请求方式
		String method=request.getMethod();
		pw.println("method="+method);//method=GET
		//6.获取web应用名
		String cp=request.getContextPath();
		pw.println("cp="+cp);//cp=/servlet
		//接收表单提交发送过来的参数
		//获得单个value值
		String strName=request.getParameter("username");
		String strPwd=request.getParameter("pwd");
		pw.println("Name:"+strName+" Pwd:"+strPwd);
		//获得多个对应value值
		String[] strInterest=request.getParameterValues("interest");
		pw.println(Arrays.toString(strInterest));
		//获取请求参数中所有的name值
		Enumeration<String> names=request.getAttributeNames();
		pw.println(names);
		//使用循环将names中的内容取出
		while(names.hasMoreElements()){
			System.out.println(names.nextElement());
		}
	}
	
	
}

修改web.xml,添加如下code

<!-- 配置RegisterServlet -->
  <servlet>
  		<servlet-name>RegisterServlet</servlet-name>
  		<!-- 配置Servlet的路径：包名+类名 -->
  		<servlet-class>request.RegisterServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  		<servlet-name>RegisterServlet</servlet-name>
  		<url-pattern>/register</url-pattern>
  </servlet-mapping>