Servlet快速入门 ***
-
页面与服务端程序有什么关系
-
什么是Servlet?
Servlet就是运行在服务端的JAVA小程序
Servlet快速入门***
- 直接new Servlet
- 设置项目的访问地址
Demo1Servlet
Demo2Servlet - 设置Servlet的访问地址
- 设置方法请求方式
- 设置参数
Demo3GetDataServlet
创建第一个Servlet
Demo01Servlet.java
@WebServlet("/demo01") //指定访问具体的哪个Servlet类
public class Demo01Servlet extends HttpServlet {
//当你使用post请求访问时，当前的doPost自动执行了
//表单里面的method设置为post
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("doPost");
}
//当你使用get请求访问时，当前的doGet自动执行了
//地址栏访问就是get
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("doGet");
}
}
不同的Servlet有不同的访问地址
Demo02Servlet .java
@WebServlet("/demo02")
public class Demo02Servlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("doPost");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("doGet");
}
}
Servlet只做三件事
Demo03GetDataServlet .java
@WebServlet("/demo03")
public class Demo03GetDataServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response); //在项目中一般，让servlet以相同的方式处理get/post请求
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1:接收请求，获取参数
String username = request.getParameter("username");//根据参数名获取参数值;
String password = request.getParameter("password");
//2:处理
System.out.println(username);
System.out.println(password);
//3:返回响应
response.getWriter().println("success");
}
}
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<!--post调用doPost方法-->
<!--action指定调哪个servlet-->
<form method="post" action="/myweb01/demo03">
账号： <input name="username" type="text"><br/>
密码： <input name="password" type="password"><br/>
<input type="submit" value="登录">
</form>
</body>
</html>