HttpServlet

作者: 丫甘九 | 来源:发表于2019-03-29 14:53 被阅读0次

10-撩课JavaEE-HttpServlet
10-码蚁JavaWeb之HttpServlet
HttpServlet
HttpServlet
HttpServlet
HttpServlet
HttpServlet
Servlet
创建httpservlet
GenericServlet & HttpServlet

在三个请求中，HttpServlet用的最多，最简单的，继承javax.servlet.http.HttpServlet类，类名说明了他与http协议有关，他有俩种用的最多的请求方式，doGet（）和DoPost（）

httpservlet类下有一个方法service（）方法

protected void service(HttpServletRequest request,HttpServletReponse reponse)
throws ServletException,IOException{

}

-servlet接口中的生命周期方法

public void service(ServletRequest request,ServletReponse reponse)
throws ServletException,IOException{

}

我们不需要重写public void service(ServletRequest request,ServletReponse reponse)
throws ServletException,IOException{

}这个方法，因为tomcat会自动将ServletRequest request,ServletReponse reponse转化成HttpServletRequest request,HttpServletReponse reponse（强转成与http有关的类型），tomcat调用生命周期方法，然后强制转化成http类型，然后调用这个含有http类型的方法

image.png

类

package baoming;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CServlet extends HttpServlet {
    public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException{
        System.out.println("doPost()....");
    }
}

html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/LxServlet/CServlet" method="post">
    <input type="submit" value="提交">

</form>
</body>
</html>

xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <display-name>LxServlet</display-name>


    <welcome-file-list>
    <!--<welcome-file>index.jsp</welcome-file>-->
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>

    <servlet>

        <servlet-name>LxServlet</servlet-name>
        <servlet-class>baoming.LxServlet</servlet-class>

    </servlet>

    <servlet-mapping>

        <servlet-name>LxServlet</servlet-name>
        <url-pattern>/LxServlet</url-pattern>

    </servlet-mapping>

    <servlet>

        <servlet-name>CServlet</servlet-name>
        <servlet-class>baoming.CServlet</servlet-class>

    </servlet>

    <servlet-mapping>

        <servlet-name>CServlet</servlet-name>
        <url-pattern>/CServlet</url-pattern>

    </servlet-mapping>
</web-app>

页面