JavaWeb中Servlet的深入理解

1.servlet:定义:

接口

2.配置servlet:

public class HelloServlet extends HttpServlet {}
HttpServlet 固定的

IDEA配置v好了
类

package com.example.demo1;

import java.io.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;

@WebServlet(name = "helloServlet", value = "/hello-servlet")

public class HelloServlet extends HttpServlet {
  private String message;

  public void init() {
      message = "Hello World!";
  }

  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
      response.setContentType("text/html");

      // Hello
      PrintWriter out = response.getWriter();
      out.println("<html><body>");
      out.println("<h1>" + message + "</h1>");
      out.println("</body></html>");
  }

  public void destroy() {
  }
}

xml：

<servlet-name>demo1</servlet-name>//把类的名称配个短的文字

<servlet-class>com.example.demo3.HelloServlet</servlet-class>//类的名称（路径）   //package com.example.demo3;可以利用包,来知道路径

<servlet-mapping>                              //映射
  <servlet-name>demo1</servlet-name>  //
  <url-pattern>/demo1</url-pattern>       //将来能通过这个路径访问类
</servlet-mapping>

/servlet-class //标签

<servlet>
      <servlet-name>demo1</servlet-name>
      <servlet-class>com.example.demo3.HelloServlet</servlet-class>
      <load-on-startup>5</load-on-startup>
  </servlet>



<servlet-mapping>
  <servlet-name>demo13</servlet-name>
  <url-pattern>demo13</url-pattern>
</servlet-mapping>