Servlet implementation of the interface

Servlet Servlet interface of the specification, define the main scope of the method.

1, public void init (ServletConfig servletConfig) (initialization)

Effect parameters:

(1) call the object's methods ServletConfig, get the name of the Servlet:

Profiles:

<?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">
    <servlet>
        <servlet-name>MyServletname</servlet-name>
        <servlet-class>MyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServletname</servlet-name>
        <url-pattern>/abc</url-pattern>
    </servlet-mapping>
</web-app>

  public void init(ServletConfig servletConfig) throws ServletException {
        String servletName=servletConfig.getServletName();
        System.out.println(servletName);
    }

operation result:

 (2) obtaining initialization parameter configuration file:

    <servlet>
        <servlet-name>MyServletname</servlet-name>
        <servlet-class>MyServlet</servlet-class>
        <init-param>
            <param-name>zhai</param-name>
            <param-value>I love study</param-value>
        </init-param>
    </servlet>

  public void init(ServletConfig servletConfig) throws ServletException {
        String paramvalue =servletConfig.getInitParameter("zhai");
        System.out.println(paramvalue);
    }

 

 (3) This method is only executed when the servlet object is created (refresh the browser)

2、public void service(ServletRequest servletRequest, ServletResponse servletResponse)方法：

ServletRequest: representative requested information.

ServletResponse: represents the response information.

Every time an object is created servletRequest and servletResponse.

 

3、public void destroy()方法：

When executed destroyed servlet objects.

4, servlet life cycle:

Initialization function only be executed if the first visit, service function will be executed each time it is accessed.

 

 dastory function when the object is destroyed (closed server).