假如，现在我做了一个给用户使用的html页面：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<h1>helloPost!</h1>
<body>
<form method="post" action="SelectBeer.do">
<p>Select beer</p>
<select name="color" size="1">
<option value="light"> light</option>
<option value="amber"> amber</option>
<option value="brown"> brown</option>
<option value="dark"> dark</option>
</select>
<center>
<input type="submit">
</center>
</form>>
</body>
</html>
<form method="post" action="SelectBeer.do"> 中的SelectBeer.do有点像资源名。最终会被http:/127.0.0.1:8080/文件名/SelectBeer.do 的形式访问到。 这是我又写了后台servlet程序，实现了get,post的方法：
package com.example.web;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Time;
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 implementation class HelloWorld2
*/
@WebServlet("/HelloWorld2")
public class HelloWorld2 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* Default constructor.
*/
public HelloWorld2() {
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
@SuppressWarnings("deprecation")
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out = response.getWriter();
//out.print("helloWorld");
//String outPut=request.getParameter("input");
out.print(request);
System.out.println(request);
String c = request.getParameter("color");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("Beer Selection Advice<br>");
String c = request.getParameter("color");
out.println("<br> Got beer color"+c);
System.out.println(c);
}
}
把html放到servlet目录下，发现前后端无法通信。
这时还需要在web.xml下进行设置。
<servlet>
<servlet-name>123123</servlet-name>
<servlet-class>com.example.web.HelloWorld2</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>123123</servlet-name>
<url-pattern>/SelectBeer.do</url-pattern>
</servlet-mapping>
servlet：可以自己设置servlet的资源名字， 然后写上对应的servlet类名
servlet-mapping：自己的servlet与资源的映射关系 发送Post请求：
返回：
发送get请求：参考：head first,servlet & jsp
参考：head first,servlet & jsp时间： 2024-08-02 04:45:13